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| 9 |
| 10 <h1 id="title">Selectors</h1> |
| 11 |
| 12 <h2>W3C Working Draft 15 December 2005</h2> |
| 13 |
| 14 <dl> |
| 15 |
| 16 <dt>This version: |
| 17 |
| 18 <dd><a href="http://www.w3.org/TR/2005/WD-css3-selectors-20051215"> |
| 19 http://www.w3.org/TR/2005/WD-css3-selectors-20051215</a> |
| 20 |
| 21 <dt>Latest version: |
| 22 |
| 23 <dd><a href="http://www.w3.org/TR/css3-selectors"> |
| 24 http://www.w3.org/TR/css3-selectors</a> |
| 25 |
| 26 <dt>Previous version: |
| 27 |
| 28 <dd><a href="http://www.w3.org/TR/2001/CR-css3-selectors-20011113"> |
| 29 http://www.w3.org/TR/2001/CR-css3-selectors-20011113</a> |
| 30 |
| 31 <dt><a name=editors-list></a>Editors: |
| 32 |
| 33 <dd class="vcard"><span class="fn">Daniel Glazman</span> (Invited Expert)</d
d> |
| 34 |
| 35 <dd class="vcard"><a lang="tr" class="url fn" href="http://www.tantek.com/">
Tantek Çelik</a> (Invited Expert) |
| 36 |
| 37 <dd class="vcard"><a href="mailto:ian@hixie.ch" class="url fn">Ian Hickson</
a> (<span |
| 38 class="company"><a href="http://www.google.com/">Google</a></span>) |
| 39 |
| 40 <dd class="vcard"><span class="fn">Peter Linss</span> (former editor, <span
class="company"><a |
| 41 href="http://www.netscape.com/">Netscape/AOL</a></span>) |
| 42 |
| 43 <dd class="vcard"><span class="fn">John Williams</span> (former editor, <spa
n class="company"><a |
| 44 href="http://www.quark.com/">Quark, Inc.</a></span>) |
| 45 |
| 46 </dl> |
| 47 |
| 48 <p class="copyright"><a |
| 49 href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright"> |
| 50 Copyright</a> © 2005 <a href="http://www.w3.org/"><abbr |
| 51 title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup> |
| 52 (<a href="http://www.csail.mit.edu/"><abbr title="Massachusetts |
| 53 Institute of Technology">MIT</abbr></a>, <a |
| 54 href="http://www.ercim.org/"><acronym title="European Research |
| 55 Consortium for Informatics and Mathematics">ERCIM</acronym></a>, <a |
| 56 href="http://www.keio.ac.jp/">Keio</a>), All Rights Reserved. W3C |
| 57 <a |
| 58 href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liabili
ty</a>, |
| 59 <a |
| 60 href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark
</a>, |
| 61 <a |
| 62 href="http://www.w3.org/Consortium/Legal/copyright-documents">document |
| 63 use</a> rules apply. |
| 64 |
| 65 <hr title="Separator for header"> |
| 66 |
| 67 </div> |
| 68 |
| 69 <h2><a name=abstract></a>Abstract</h2> |
| 70 |
| 71 <p><em>Selectors</em> are patterns that match against elements in a |
| 72 tree. Selectors have been optimized for use with HTML and XML, and |
| 73 are designed to be usable in performance-critical code.</p> |
| 74 |
| 75 <p><acronym title="Cascading Style Sheets">CSS</acronym> (Cascading |
| 76 Style Sheets) is a language for describing the rendering of <acronym |
| 77 title="Hypertext Markup Language">HTML</acronym> and <acronym |
| 78 title="Extensible Markup Language">XML</acronym> documents on |
| 79 screen, on paper, in speech, etc. CSS uses Selectors for binding |
| 80 style properties to elements in the document. This document |
| 81 describes extensions to the selectors defined in CSS level 2. These |
| 82 extended selectors will be used by CSS level 3. |
| 83 |
| 84 <p>Selectors define the following function:</p> |
| 85 |
| 86 <pre>expression ∗ element → boolean</pre> |
| 87 |
| 88 <p>That is, given an element and a selector, this specification |
| 89 defines whether that element matches the selector.</p> |
| 90 |
| 91 <p>These expressions can also be used, for instance, to select a set |
| 92 of elements, or a single element from a set of elements, by |
| 93 evaluating the expression across all the elements in a |
| 94 subtree. <acronym title="Simple Tree Transformation |
| 95 Sheets">STTS</acronym> (Simple Tree Transformation Sheets), a |
| 96 language for transforming XML trees, uses this mechanism. <a href="#refsSTTS">
[STTS]</a></p> |
| 97 |
| 98 <h2><a name=status></a>Status of this document</h2> |
| 99 |
| 100 <p><em>This section describes the status of this document at the |
| 101 time of its publication. Other documents may supersede this |
| 102 document. A list of current W3C publications and the latest revision |
| 103 of this technical report can be found in the <a |
| 104 href="http://www.w3.org/TR/">W3C technical reports index at |
| 105 http://www.w3.org/TR/.</a></em></p> |
| 106 |
| 107 <p>This document describes the selectors that already exist in <a |
| 108 href="#refsCSS1"><abbr title="CSS level 1">CSS1</abbr></a> and <a |
| 109 href="#refsCSS21"><abbr title="CSS level 2">CSS2</abbr></a>, and |
| 110 also proposes new selectors for <abbr title="CSS level |
| 111 3">CSS3</abbr> and other languages that may need them.</p> |
| 112 |
| 113 <p>The CSS Working Group doesn't expect that all implementations of |
| 114 CSS3 will have to implement all selectors. Instead, there will |
| 115 probably be a small number of variants of CSS3, called profiles. For |
| 116 example, it may be that only a profile for interactive user agents |
| 117 will include all of the selectors.</p> |
| 118 |
| 119 <p>This specification is a last call working draft for the the <a |
| 120 href="http://www.w3.org/Style/CSS/members">CSS Working Group</a> |
| 121 (<a href="/Style/">Style Activity</a>). This |
| 122 document is a revision of the <a |
| 123 href="http://www.w3.org/TR/2001/CR-css3-selectors-20011113/">Candidate |
| 124 Recommendation dated 2001 November 13</a>, and has incorporated |
| 125 implementation feedback received in the past few years. It is |
| 126 expected that this last call will proceed straight to Proposed |
| 127 Recommendation stage since it is believed that interoperability will |
| 128 be demonstrable.</p> |
| 129 |
| 130 <p>All persons are encouraged to review and implement this |
| 131 specification and return comments to the (<a |
| 132 href="http://lists.w3.org/Archives/Public/www-style/">archived</a>) |
| 133 public mailing list <a |
| 134 href="http://www.w3.org/Mail/Lists.html#www-style">www-style</a> |
| 135 (see <a href="http://www.w3.org/Mail/Request">instructions</a>). W3C |
| 136 Members can also send comments directly to the CSS Working |
| 137 Group. |
| 138 The deadline for comments is 14 January 2006.</p> |
| 139 |
| 140 <p>This is still a draft document and may be updated, replaced, or |
| 141 obsoleted by other documents at any time. It is inappropriate to |
| 142 cite a W3C Working Draft as other than "work in progress". |
| 143 |
| 144 <p>This document may be available in <a |
| 145 href="http://www.w3.org/Style/css3-selectors-updates/translations">translation
</a>. |
| 146 The English version of this specification is the only normative |
| 147 version. |
| 148 |
| 149 <div class="subtoc"> |
| 150 |
| 151 <h2 id="test10"><a name=contents>Table of contents</a></h2> |
| 152 |
| 153 <ul class="toc"> |
| 154 <li class="tocline2"><a href="#context">1. Introduction</a> |
| 155 <ul> |
| 156 <li><a href="#dependencies">1.1. Dependencies</a> </li> |
| 157 <li><a href="#terminology">1.2. Terminology</a> </li> |
| 158 <li><a href="#changesFromCSS2">1.3. Changes from CSS2</a> </li> |
| 159 </ul> |
| 160 <li class="tocline2"><a href="#selectors">2. Selectors</a> |
| 161 <li class="tocline2"><a href="#casesens">3. Case sensitivity</a> |
| 162 <li class="tocline2"><a href="#selector-syntax">4. Selector syntax</a> |
| 163 <li class="tocline2"><a href="#grouping">5. Groups of selectors</a> |
| 164 <li class="tocline2"><a href="#simple-selectors">6. Simple selectors</a> |
| 165 <ul class="toc"> |
| 166 <li class="tocline3"><a href="#type-selectors">6.1. Type selectors</a> |
| 167 <ul class="toc"> |
| 168 <li class="tocline4"><a href="#typenmsp">6.1.1. Type selectors and names
paces</a></li> |
| 169 </ul> |
| 170 <li class="tocline3"><a href="#universal-selector">6.2. Universal selector
</a> |
| 171 <ul> |
| 172 <li><a href="#univnmsp">6.2.1. Universal selector and namespaces</a></li
> |
| 173 </ul> |
| 174 <li class="tocline3"><a href="#attribute-selectors">6.3. Attribute selecto
rs</a> |
| 175 <ul class="toc"> |
| 176 <li class="tocline4"><a href="#attribute-representation">6.3.1. Represen
tation of attributes and attributes values</a> |
| 177 <li><a href="#attribute-substrings">6.3.2. Substring matching attribute
selectors</a> |
| 178 <li class="tocline4"><a href="#attrnmsp">6.3.3. Attribute selectors and
namespaces</a> |
| 179 <li class="tocline4"><a href="#def-values">6.3.4. Default attribute valu
es in DTDs</a></li> |
| 180 </ul> |
| 181 <li class="tocline3"><a href="#class-html">6.4. Class selectors</a> |
| 182 <li class="tocline3"><a href="#id-selectors">6.5. ID selectors</a> |
| 183 <li class="tocline3"><a href="#pseudo-classes">6.6. Pseudo-classes</a> |
| 184 <ul class="toc"> |
| 185 <li class="tocline4"><a href="#dynamic-pseudos">6.6.1. Dynamic pseudo-cl
asses</a> |
| 186 <li class="tocline4"><a href="#target-pseudo">6.6.2. The :target pseudo-
class</a> |
| 187 <li class="tocline4"><a href="#lang-pseudo">6.6.3. The :lang() pseudo-cl
ass</a> |
| 188 <li class="tocline4"><a href="#UIstates">6.6.4. UI element states pseudo
-classes</a> |
| 189 <li class="tocline4"><a href="#structural-pseudos">6.6.5. Structural pse
udo-classes</a> |
| 190 <ul> |
| 191 <li><a href="#root-pseudo">:root pseudo-class</a> |
| 192 <li><a href="#nth-child-pseudo">:nth-child() pseudo-class</a> |
| 193 <li><a href="#nth-last-child-pseudo">:nth-last-child()</a> |
| 194 <li><a href="#nth-of-type-pseudo">:nth-of-type() pseudo-class</a> |
| 195 <li><a href="#nth-last-of-type-pseudo">:nth-last-of-type()</a> |
| 196 <li><a href="#first-child-pseudo">:first-child pseudo-class</a> |
| 197 <li><a href="#last-child-pseudo">:last-child pseudo-class</a> |
| 198 <li><a href="#first-of-type-pseudo">:first-of-type pseudo-class</a> |
| 199 <li><a href="#last-of-type-pseudo">:last-of-type pseudo-class</a> |
| 200 <li><a href="#only-child-pseudo">:only-child pseudo-class</a> |
| 201 <li><a href="#only-of-type-pseudo">:only-of-type pseudo-class</a> |
| 202 <li><a href="#empty-pseudo">:empty pseudo-class</a></li> |
| 203 </ul> |
| 204 <li class="tocline4"><a href="#negation">6.6.7. The negation pseudo-clas
s</a></li> |
| 205 </ul> |
| 206 </li> |
| 207 </ul> |
| 208 <li><a href="#pseudo-elements">7. Pseudo-elements</a> |
| 209 <ul> |
| 210 <li><a href="#first-line">7.1. The ::first-line pseudo-element</a> |
| 211 <li><a href="#first-letter">7.2. The ::first-letter pseudo-element</a> |
| 212 <li><a href="#UIfragments">7.3. The ::selection pseudo-element</a> |
| 213 <li><a href="#gen-content">7.4. The ::before and ::after pseudo-elements</
a></li> |
| 214 </ul> |
| 215 <li class="tocline2"><a href="#combinators">8. Combinators</a> |
| 216 <ul class="toc"> |
| 217 <li class="tocline3"><a href="#descendant-combinators">8.1. Descendant com
binators</a> |
| 218 <li class="tocline3"><a href="#child-combinators">8.2. Child combinators</
a> |
| 219 <li class="tocline3"><a href="#sibling-combinators">8.3. Sibling combinato
rs</a> |
| 220 <ul class="toc"> |
| 221 <li class="tocline4"><a href="#adjacent-sibling-combinators">8.3.1. Adja
cent sibling combinator</a> |
| 222 <li class="tocline4"><a href="#general-sibling-combinators">8.3.2. Gener
al sibling combinator</a></li> |
| 223 </ul> |
| 224 </li> |
| 225 </ul> |
| 226 <li class="tocline2"><a href="#specificity">9. Calculating a selector's spec
ificity</a> |
| 227 <li class="tocline2"><a href="#w3cselgrammar">10. The grammar of Selectors</
a> |
| 228 <ul class="toc"> |
| 229 <li class="tocline3"><a href="#grammar">10.1. Grammar</a> |
| 230 <li class="tocline3"><a href="#lex">10.2. Lexical scanner</a></li> |
| 231 </ul> |
| 232 <li class="tocline2"><a href="#downlevel">11. Namespaces and down-level clie
nts</a> |
| 233 <li class="tocline2"><a href="#profiling">12. Profiles</a> |
| 234 <li><a href="#Conformance">13. Conformance and requirements</a> |
| 235 <li><a href="#Tests">14. Tests</a> |
| 236 <li><a href="#ACKS">15. Acknowledgements</a> |
| 237 <li class="tocline2"><a href="#references">16. References</a> |
| 238 </ul> |
| 239 |
| 240 </div> |
| 241 |
| 242 <h2><a name=context>1. Introduction</a></h2> |
| 243 |
| 244 <h3><a name=dependencies></a>1.1. Dependencies</h3> |
| 245 |
| 246 <p>Some features of this specification are specific to CSS, or have |
| 247 particular limitations or rules specific to CSS. In this |
| 248 specification, these have been described in terms of CSS2.1. <a |
| 249 href="#refsCSS21">[CSS21]</a></p> |
| 250 |
| 251 <h3><a name=terminology></a>1.2. Terminology</h3> |
| 252 |
| 253 <p>All of the text of this specification is normative except |
| 254 examples, notes, and sections explicitly marked as |
| 255 non-normative.</p> |
| 256 |
| 257 <h3><a name=changesFromCSS2></a>1.3. Changes from CSS2</h3> |
| 258 |
| 259 <p><em>This section is non-normative.</em></p> |
| 260 |
| 261 <p>The main differences between the selectors in CSS2 and those in |
| 262 Selectors are: |
| 263 |
| 264 <ul> |
| 265 |
| 266 <li>the list of basic definitions (selector, group of selectors, |
| 267 simple selector, etc.) has been changed; in particular, what was |
| 268 referred to in CSS2 as a simple selector is now called a sequence |
| 269 of simple selectors, and the term "simple selector" is now used for |
| 270 the components of this sequence</li> |
| 271 |
| 272 <li>an optional namespace component is now allowed in type element |
| 273 selectors, the universal selector and attribute selectors</li> |
| 274 |
| 275 <li>a <a href="#general-sibling-combinators">new combinator</a> has been intr
oduced</li> |
| 276 |
| 277 <li>new simple selectors including substring matching attribute |
| 278 selectors, and new pseudo-classes</li> |
| 279 |
| 280 <li>new pseudo-elements, and introduction of the "::" convention |
| 281 for pseudo-elements</li> |
| 282 |
| 283 <li>the grammar has been rewritten</li> |
| 284 |
| 285 <li>profiles to be added to specifications integrating Selectors |
| 286 and defining the set of selectors which is actually supported by |
| 287 each specification</li> |
| 288 |
| 289 <li>Selectors are now a CSS3 Module and an independent |
| 290 specification; other specifications can now refer to this document |
| 291 independently of CSS</li> |
| 292 |
| 293 <li>the specification now has its own test suite</li> |
| 294 |
| 295 </ul> |
| 296 |
| 297 <h2><a name=selectors></a>2. Selectors</h2> |
| 298 |
| 299 <p><em>This section is non-normative, as it merely summarizes the |
| 300 following sections.</em></p> |
| 301 |
| 302 <p>A Selector represents a structure. This structure can be used as a |
| 303 condition (e.g. in a CSS rule) that determines which elements a |
| 304 selector matches in the document tree, or as a flat description of the |
| 305 HTML or XML fragment corresponding to that structure.</p> |
| 306 |
| 307 <p>Selectors may range from simple element names to rich contextual |
| 308 representations.</p> |
| 309 |
| 310 <p>The following table summarizes the Selector syntax:</p> |
| 311 |
| 312 <table class="selectorsReview"> |
| 313 <thead> |
| 314 <tr> |
| 315 <th class="pattern">Pattern</th> |
| 316 <th class="meaning">Meaning</th> |
| 317 <th class="described">Described in section</th> |
| 318 <th class="origin">First defined in CSS level</th></tr> |
| 319 <tbody> |
| 320 <tr> |
| 321 <td class="pattern">*</td> |
| 322 <td class="meaning">any element</td> |
| 323 <td class="described"><a |
| 324 href="#universal-selector">Universal |
| 325 selector</a></td> |
| 326 <td class="origin">2</td></tr> |
| 327 <tr> |
| 328 <td class="pattern">E</td> |
| 329 <td class="meaning">an element of type E</td> |
| 330 <td class="described"><a |
| 331 href="#type-selectors">Type selector</a></td> |
| 332 <td class="origin">1</td></tr> |
| 333 <tr> |
| 334 <td class="pattern">E[foo]</td> |
| 335 <td class="meaning">an E element with a "foo" attribute</td> |
| 336 <td class="described"><a |
| 337 href="#attribute-selectors">Attribute |
| 338 selectors</a></td> |
| 339 <td class="origin">2</td></tr> |
| 340 <tr> |
| 341 <td class="pattern">E[foo="bar"]</td> |
| 342 <td class="meaning">an E element whose "foo" attribute value is exactly |
| 343 equal to "bar"</td> |
| 344 <td class="described"><a |
| 345 href="#attribute-selectors">Attribute |
| 346 selectors</a></td> |
| 347 <td class="origin">2</td></tr> |
| 348 <tr> |
| 349 <td class="pattern">E[foo~="bar"]</td> |
| 350 <td class="meaning">an E element whose "foo" attribute value is a list of |
| 351 space-separated values, one of which is exactly equal to "bar"</td> |
| 352 <td class="described"><a |
| 353 href="#attribute-selectors">Attribute |
| 354 selectors</a></td> |
| 355 <td class="origin">2</td></tr> |
| 356 <tr> |
| 357 <td class="pattern">E[foo^="bar"]</td> |
| 358 <td class="meaning">an E element whose "foo" attribute value begins exactly |
| 359 with the string "bar"</td> |
| 360 <td class="described"><a |
| 361 href="#attribute-selectors">Attribute |
| 362 selectors</a></td> |
| 363 <td class="origin">3</td></tr> |
| 364 <tr> |
| 365 <td class="pattern">E[foo$="bar"]</td> |
| 366 <td class="meaning">an E element whose "foo" attribute value ends exactly |
| 367 with the string "bar"</td> |
| 368 <td class="described"><a |
| 369 href="#attribute-selectors">Attribute |
| 370 selectors</a></td> |
| 371 <td class="origin">3</td></tr> |
| 372 <tr> |
| 373 <td class="pattern">E[foo*="bar"]</td> |
| 374 <td class="meaning">an E element whose "foo" attribute value contains the |
| 375 substring "bar"</td> |
| 376 <td class="described"><a |
| 377 href="#attribute-selectors">Attribute |
| 378 selectors</a></td> |
| 379 <td class="origin">3</td></tr> |
| 380 <tr> |
| 381 <td class="pattern">E[hreflang|="en"]</td> |
| 382 <td class="meaning">an E element whose "hreflang" attribute has a hyphen-sep
arated |
| 383 list of values beginning (from the left) with "en"</td> |
| 384 <td class="described"><a |
| 385 href="#attribute-selectors">Attribute |
| 386 selectors</a></td> |
| 387 <td class="origin">2</td></tr> |
| 388 <tr> |
| 389 <td class="pattern">E:root</td> |
| 390 <td class="meaning">an E element, root of the document</td> |
| 391 <td class="described"><a |
| 392 href="#structural-pseudos">Structural |
| 393 pseudo-classes</a></td> |
| 394 <td class="origin">3</td></tr> |
| 395 <tr> |
| 396 <td class="pattern">E:nth-child(n)</td> |
| 397 <td class="meaning">an E element, the n-th child of its parent</td> |
| 398 <td class="described"><a |
| 399 href="#structural-pseudos">Structural |
| 400 pseudo-classes</a></td> |
| 401 <td class="origin">3</td></tr> |
| 402 <tr> |
| 403 <td class="pattern">E:nth-last-child(n)</td> |
| 404 <td class="meaning">an E element, the n-th child of its parent, counting |
| 405 from the last one</td> |
| 406 <td class="described"><a |
| 407 href="#structural-pseudos">Structural |
| 408 pseudo-classes</a></td> |
| 409 <td class="origin">3</td></tr> |
| 410 <tr> |
| 411 <td class="pattern">E:nth-of-type(n)</td> |
| 412 <td class="meaning">an E element, the n-th sibling of its type</td> |
| 413 <td class="described"><a |
| 414 href="#structural-pseudos">Structural |
| 415 pseudo-classes</a></td> |
| 416 <td class="origin">3</td></tr> |
| 417 <tr> |
| 418 <td class="pattern">E:nth-last-of-type(n)</td> |
| 419 <td class="meaning">an E element, the n-th sibling of its type, counting |
| 420 from the last one</td> |
| 421 <td class="described"><a |
| 422 href="#structural-pseudos">Structural |
| 423 pseudo-classes</a></td> |
| 424 <td class="origin">3</td></tr> |
| 425 <tr> |
| 426 <td class="pattern">E:first-child</td> |
| 427 <td class="meaning">an E element, first child of its parent</td> |
| 428 <td class="described"><a |
| 429 href="#structural-pseudos">Structural |
| 430 pseudo-classes</a></td> |
| 431 <td class="origin">2</td></tr> |
| 432 <tr> |
| 433 <td class="pattern">E:last-child</td> |
| 434 <td class="meaning">an E element, last child of its parent</td> |
| 435 <td class="described"><a |
| 436 href="#structural-pseudos">Structural |
| 437 pseudo-classes</a></td> |
| 438 <td class="origin">3</td></tr> |
| 439 <tr> |
| 440 <td class="pattern">E:first-of-type</td> |
| 441 <td class="meaning">an E element, first sibling of its type</td> |
| 442 <td class="described"><a |
| 443 href="#structural-pseudos">Structural |
| 444 pseudo-classes</a></td> |
| 445 <td class="origin">3</td></tr> |
| 446 <tr> |
| 447 <td class="pattern">E:last-of-type</td> |
| 448 <td class="meaning">an E element, last sibling of its type</td> |
| 449 <td class="described"><a |
| 450 href="#structural-pseudos">Structural |
| 451 pseudo-classes</a></td> |
| 452 <td class="origin">3</td></tr> |
| 453 <tr> |
| 454 <td class="pattern">E:only-child</td> |
| 455 <td class="meaning">an E element, only child of its parent</td> |
| 456 <td class="described"><a |
| 457 href="#structural-pseudos">Structural |
| 458 pseudo-classes</a></td> |
| 459 <td class="origin">3</td></tr> |
| 460 <tr> |
| 461 <td class="pattern">E:only-of-type</td> |
| 462 <td class="meaning">an E element, only sibling of its type</td> |
| 463 <td class="described"><a |
| 464 href="#structural-pseudos">Structural |
| 465 pseudo-classes</a></td> |
| 466 <td class="origin">3</td></tr> |
| 467 <tr> |
| 468 <td class="pattern">E:empty</td> |
| 469 <td class="meaning">an E element that has no children (including text |
| 470 nodes)</td> |
| 471 <td class="described"><a |
| 472 href="#structural-pseudos">Structural |
| 473 pseudo-classes</a></td> |
| 474 <td class="origin">3</td></tr> |
| 475 <tr> |
| 476 <td class="pattern">E:link<br>E:visited</td> |
| 477 <td class="meaning">an E element being the source anchor of a hyperlink of |
| 478 which the target is not yet visited (:link) or already visited |
| 479 (:visited)</td> |
| 480 <td class="described"><a |
| 481 href="#link">The link |
| 482 pseudo-classes</a></td> |
| 483 <td class="origin">1</td></tr> |
| 484 <tr> |
| 485 <td class="pattern">E:active<br>E:hover<br>E:focus</td> |
| 486 <td class="meaning">an E element during certain user actions</td> |
| 487 <td class="described"><a |
| 488 href="#useraction-pseudos">The user |
| 489 action pseudo-classes</a></td> |
| 490 <td class="origin">1 and 2</td></tr> |
| 491 <tr> |
| 492 <td class="pattern">E:target</td> |
| 493 <td class="meaning">an E element being the target of the referring URI</td> |
| 494 <td class="described"><a |
| 495 href="#target-pseudo">The target |
| 496 pseudo-class</a></td> |
| 497 <td class="origin">3</td></tr> |
| 498 <tr> |
| 499 <td class="pattern">E:lang(fr)</td> |
| 500 <td class="meaning">an element of type E in language "fr" (the document |
| 501 language specifies how language is determined)</td> |
| 502 <td class="described"><a |
| 503 href="#lang-pseudo">The :lang() |
| 504 pseudo-class</a></td> |
| 505 <td class="origin">2</td></tr> |
| 506 <tr> |
| 507 <td class="pattern">E:enabled<br>E:disabled</td> |
| 508 <td class="meaning">a user interface element E which is enabled or |
| 509 disabled</td> |
| 510 <td class="described"><a |
| 511 href="#UIstates">The UI element states |
| 512 pseudo-classes</a></td> |
| 513 <td class="origin">3</td></tr> |
| 514 <tr> |
| 515 <td class="pattern">E:checked<!--<br>E:indeterminate--></td> |
| 516 <td class="meaning">a user interface element E which is checked<!-- or in an |
| 517 indeterminate state--> (for instance a radio-button or checkbox)</td> |
| 518 <td class="described"><a |
| 519 href="#UIstates">The UI element states |
| 520 pseudo-classes</a></td> |
| 521 <td class="origin">3</td></tr> |
| 522 <tr> |
| 523 <td class="pattern">E::first-line</td> |
| 524 <td class="meaning">the first formatted line of an E element</td> |
| 525 <td class="described"><a |
| 526 href="#first-line">The ::first-line |
| 527 pseudo-element</a></td> |
| 528 <td class="origin">1</td></tr> |
| 529 <tr> |
| 530 <td class="pattern">E::first-letter</td> |
| 531 <td class="meaning">the first formatted letter of an E element</td> |
| 532 <td class="described"><a |
| 533 href="#first-letter">The ::first-letter |
| 534 pseudo-element</a></td> |
| 535 <td class="origin">1</td></tr> |
| 536 <tr> |
| 537 <td class="pattern">E::selection</td> |
| 538 <td class="meaning">the portion of an E element that is currently |
| 539 selected/highlighted by the user</td> |
| 540 <td class="described"><a |
| 541 href="#UIfragments">The UI element |
| 542 fragments pseudo-elements</a></td> |
| 543 <td class="origin">3</td></tr> |
| 544 <tr> |
| 545 <td class="pattern">E::before</td> |
| 546 <td class="meaning">generated content before an E element</td> |
| 547 <td class="described"><a |
| 548 href="#gen-content">The ::before |
| 549 pseudo-element</a></td> |
| 550 <td class="origin">2</td></tr> |
| 551 <tr> |
| 552 <td class="pattern">E::after</td> |
| 553 <td class="meaning">generated content after an E element</td> |
| 554 <td class="described"><a |
| 555 href="#gen-content">The ::after |
| 556 pseudo-element</a></td> |
| 557 <td class="origin">2</td></tr> |
| 558 <tr> |
| 559 <td class="pattern">E.warning</td> |
| 560 <td class="meaning">an E element whose class is |
| 561 "warning" (the document language specifies how class is determined).</td> |
| 562 <td class="described"><a |
| 563 href="#class-html">Class |
| 564 selectors</a></td> |
| 565 <td class="origin">1</td></tr> |
| 566 <tr> |
| 567 <td class="pattern">E#myid</td> |
| 568 <td class="meaning">an E element with ID equal to "myid".</td> |
| 569 <td class="described"><a |
| 570 href="#id-selectors">ID |
| 571 selectors</a></td> |
| 572 <td class="origin">1</td></tr> |
| 573 <tr> |
| 574 <td class="pattern">E:not(s)</td> |
| 575 <td class="meaning">an E element that does not match simple selector s</td> |
| 576 <td class="described"><a |
| 577 href="#negation">Negation |
| 578 pseudo-class</a></td> |
| 579 <td class="origin">3</td></tr> |
| 580 <tr> |
| 581 <td class="pattern">E F</td> |
| 582 <td class="meaning">an F element descendant of an E element</td> |
| 583 <td class="described"><a |
| 584 href="#descendant-combinators">Descendant |
| 585 combinator</a></td> |
| 586 <td class="origin">1</td></tr> |
| 587 <tr> |
| 588 <td class="pattern">E > F</td> |
| 589 <td class="meaning">an F element child of an E element</td> |
| 590 <td class="described"><a |
| 591 href="#child-combinators">Child |
| 592 combinator</a></td> |
| 593 <td class="origin">2</td></tr> |
| 594 <tr> |
| 595 <td class="pattern">E + F</td> |
| 596 <td class="meaning">an F element immediately preceded by an E element</td> |
| 597 <td class="described"><a |
| 598 href="#adjacent-sibling-combinators">Adjacent sibling combinator</a></td> |
| 599 <td class="origin">2</td></tr> |
| 600 <tr> |
| 601 <td class="pattern">E ~ F</td> |
| 602 <td class="meaning">an F element preceded by an E element</td> |
| 603 <td class="described"><a |
| 604 href="#general-sibling-combinators">General sibling combinator</a></td> |
| 605 <td class="origin">3</td></tr></tbody></table> |
| 606 |
| 607 <p>The meaning of each selector is derived from the table above by |
| 608 prepending "matches" to the contents of each cell in the "Meaning" |
| 609 column.</p> |
| 610 |
| 611 <h2><a name=casesens>3. Case sensitivity</a></h2> |
| 612 |
| 613 <p>The case sensitivity of document language element names, attribute |
| 614 names, and attribute values in selectors depends on the document |
| 615 language. For example, in HTML, element names are case-insensitive, |
| 616 but in XML, they are case-sensitive.</p> |
| 617 |
| 618 <h2><a name=selector-syntax>4. Selector syntax</a></h2> |
| 619 |
| 620 <p>A <dfn><a name=selector>selector</a></dfn> is a chain of one |
| 621 or more <a href="#sequence">sequences of simple selectors</a> |
| 622 separated by <a href="#combinators">combinators</a>.</p> |
| 623 |
| 624 <p>A <dfn><a name=sequence>sequence of simple selectors</a></dfn> |
| 625 is a chain of <a href="#simple-selectors-dfn">simple selectors</a> |
| 626 that are not separated by a <a href="#combinators">combinator</a>. It |
| 627 always begins with a <a href="#type-selectors">type selector</a> or a |
| 628 <a href="#universal-selector">universal selector</a>. No other type |
| 629 selector or universal selector is allowed in the sequence.</p> |
| 630 |
| 631 <p>A <dfn><a name=simple-selectors-dfn></a><a |
| 632 href="#simple-selectors">simple selector</a></dfn> is either a <a |
| 633 href="#type-selectors">type selector</a>, <a |
| 634 href="#universal-selector">universal selector</a>, <a |
| 635 href="#attribute-selectors">attribute selector</a>, <a |
| 636 href="#class-html">class selector</a>, <a |
| 637 href="#id-selectors">ID selector</a>, <a |
| 638 href="#content-selectors">content selector</a>, or <a |
| 639 href="#pseudo-classes">pseudo-class</a>. One <a |
| 640 href="#pseudo-elements">pseudo-element</a> may be appended to the last |
| 641 sequence of simple selectors.</p> |
| 642 |
| 643 <p><dfn>Combinators</dfn> are: white space, "greater-than |
| 644 sign" (U+003E, <code>></code>), "plus sign" (U+002B, |
| 645 <code>+</code>) and "tilde" (U+007E, <code>~</code>). White |
| 646 space may appear between a combinator and the simple selectors around |
| 647 it. <a name=whitespace></a>Only the characters "space" (U+0020), "tab" |
| 648 (U+0009), "line feed" (U+000A), "carriage return" (U+000D), and "form |
| 649 feed" (U+000C) can occur in white space. Other space-like characters, |
| 650 such as "em-space" (U+2003) and "ideographic space" (U+3000), are |
| 651 never part of white space.</p> |
| 652 |
| 653 <p>The elements of a document tree that are represented by a selector |
| 654 are the <dfn><a name=subject></a>subjects of the selector</dfn>. A |
| 655 selector consisting of a single sequence of simple selectors |
| 656 represents any element satisfying its requirements. Prepending another |
| 657 sequence of simple selectors and a combinator to a sequence imposes |
| 658 additional matching constraints, so the subjects of a selector are |
| 659 always a subset of the elements represented by the last sequence of |
| 660 simple selectors.</p> |
| 661 |
| 662 <p>An empty selector, containing no sequence of simple selectors and |
| 663 no pseudo-element, is an <a href="#Conformance">invalid |
| 664 selector</a>.</p> |
| 665 |
| 666 <h2><a name=grouping>5. Groups of selectors</a></h2> |
| 667 |
| 668 <p>When several selectors share the same declarations, they may be |
| 669 grouped into a comma-separated list. (A comma is U+002C.)</p> |
| 670 |
| 671 <div class="example"> |
| 672 <p>CSS examples:</p> |
| 673 <p>In this example, we condense three rules with identical |
| 674 declarations into one. Thus,</p> |
| 675 <pre>h1 { font-family: sans-serif } |
| 676 h2 { font-family: sans-serif } |
| 677 h3 { font-family: sans-serif }</pre> |
| 678 <p>is equivalent to:</p> |
| 679 <pre>h1, h2, h3 { font-family: sans-serif }</pre> |
| 680 </div> |
| 681 |
| 682 <p><strong>Warning</strong>: the equivalence is true in this example |
| 683 because all the selectors are valid selectors. If just one of these |
| 684 selectors were invalid, the entire group of selectors would be |
| 685 invalid. This would invalidate the rule for all three heading |
| 686 elements, whereas in the former case only one of the three individual |
| 687 heading rules would be invalidated.</p> |
| 688 |
| 689 |
| 690 <h2><a name=simple-selectors>6. Simple selectors</a></h2> |
| 691 |
| 692 <h3><a name=type-selectors>6.1. Type selector</a></h3> |
| 693 |
| 694 <p>A <dfn>type selector</dfn> is the name of a document language |
| 695 element type. A type selector represents an instance of the element |
| 696 type in the document tree.</p> |
| 697 |
| 698 <div class="example"> |
| 699 <p>Example:</p> |
| 700 <p>The following selector represents an <code>h1</code> element in the document
tree:</p> |
| 701 <pre>h1</pre> |
| 702 </div> |
| 703 |
| 704 |
| 705 <h4><a name=typenmsp>6.1.1. Type selectors and namespaces</a></h4> |
| 706 |
| 707 <p>Type selectors allow an optional namespace (<a |
| 708 href="#refsXMLNAMES">[XMLNAMES]</a>) component. A namespace prefix |
| 709 that has been previously declared may be prepended to the element name |
| 710 separated by the namespace separator "vertical bar" |
| 711 (U+007C, <code>|</code>).</p> |
| 712 |
| 713 <p>The namespace component may be left empty to indicate that the |
| 714 selector is only to represent elements with no declared namespace.</p> |
| 715 |
| 716 <p>An asterisk may be used for the namespace prefix, indicating that |
| 717 the selector represents elements in any namespace (including elements |
| 718 with no namespace).</p> |
| 719 |
| 720 <p>Element type selectors that have no namespace component (no |
| 721 namespace separator), represent elements without regard to the |
| 722 element's namespace (equivalent to "<code>*|</code>") unless a default |
| 723 namespace has been declared. If a default namespace has been declared, |
| 724 the selector will represent only elements in the default |
| 725 namespace.</p> |
| 726 |
| 727 <p>A type selector containing a namespace prefix that has not been |
| 728 previously declared is an <a href="#Conformance">invalid</a> selector. |
| 729 The mechanism for declaring a namespace prefix is left up to the |
| 730 language implementing Selectors. In CSS, such a mechanism is defined |
| 731 in the General Syntax module.</p> |
| 732 |
| 733 <p>In a namespace-aware client, element type selectors will only match |
| 734 against the <a |
| 735 href="http://www.w3.org/TR/REC-xml-names/#NT-LocalPart">local part</a> |
| 736 of the element's <a |
| 737 href="http://www.w3.org/TR/REC-xml-names/#ns-qualnames">qualified |
| 738 name</a>. See <a href="#downlevel">below</a> for notes about matching |
| 739 behaviors in down-level clients.</p> |
| 740 |
| 741 <p>In summary:</p> |
| 742 |
| 743 <dl> |
| 744 <dt><code>ns|E</code></dt> |
| 745 <dd>elements with name E in namespace ns</dd> |
| 746 <dt><code>*|E</code></dt> |
| 747 <dd>elements with name E in any namespace, including those without any |
| 748 declared namespace</dd> |
| 749 <dt><code>|E</code></dt> |
| 750 <dd>elements with name E without any declared namespace</dd> |
| 751 <dt><code>E</code></dt> |
| 752 <dd>if no default namespace has been specified, this is equivalent to *|E. |
| 753 Otherwise it is equivalent to ns|E where ns is the default namespace.</dd> |
| 754 </dl> |
| 755 |
| 756 <div class="example"> |
| 757 <p>CSS examples:</p> |
| 758 |
| 759 <pre>@namespace foo url(http://www.example.com); |
| 760 foo|h1 { color: blue } |
| 761 foo|* { color: yellow } |
| 762 |h1 { color: red } |
| 763 *|h1 { color: green } |
| 764 h1 { color: green }</pre> |
| 765 |
| 766 <p>The first rule will match only <code>h1</code> elements in the |
| 767 "http://www.example.com" namespace.</p> |
| 768 |
| 769 <p>The second rule will match all elements in the |
| 770 "http://www.example.com" namespace.</p> |
| 771 |
| 772 <p>The third rule will match only <code>h1</code> elements without |
| 773 any declared namespace.</p> |
| 774 |
| 775 <p>The fourth rule will match <code>h1</code> elements in any |
| 776 namespace (including those without any declared namespace).</p> |
| 777 |
| 778 <p>The last rule is equivalent to the fourth rule because no default |
| 779 namespace has been defined.</p> |
| 780 |
| 781 </div> |
| 782 |
| 783 <h3><a name=universal-selector>6.2. Universal selector</a> </h3> |
| 784 |
| 785 <p>The <dfn>universal selector</dfn>, written "asterisk" |
| 786 (<code>*</code>), represents the qualified name of any element |
| 787 type. It represents any single element in the document tree in any |
| 788 namespace (including those without any declared namespace) if no |
| 789 default namespace has been specified. If a default namespace has been |
| 790 specified, see <a href="#univnmsp">Universal selector and |
| 791 Namespaces</a> below.</p> |
| 792 |
| 793 <p>If the universal selector is not the only component of a sequence |
| 794 of simple selectors, the <code>*</code> may be omitted.</p> |
| 795 |
| 796 <div class="example"> |
| 797 <p>Examples:</p> |
| 798 <ul> |
| 799 <li><code>*[hreflang|=en]</code> and <code>[hreflang|=en]</code> are equivalen
t,</li> |
| 800 <li><code>*.warning</code> and <code>.warning</code> are equivalent,</li> |
| 801 <li><code>*#myid</code> and <code>#myid</code> are equivalent.</li> |
| 802 </ul> |
| 803 </div> |
| 804 |
| 805 <p class="note"><strong>Note:</strong> it is recommended that the |
| 806 <code>*</code>, representing the universal selector, not be |
| 807 omitted.</p> |
| 808 |
| 809 <h4><a name=univnmsp>6.2.1. Universal selector and namespaces</a></h4> |
| 810 |
| 811 <p>The universal selector allows an optional namespace component. It |
| 812 is used as follows:</p> |
| 813 |
| 814 <dl> |
| 815 <dt><code>ns|*</code></dt> |
| 816 <dd>all elements in namespace ns</dd> |
| 817 <dt><code>*|*</code></dt> |
| 818 <dd>all elements</dd> |
| 819 <dt><code>|*</code></dt> |
| 820 <dd>all elements without any declared namespace</dd> |
| 821 <dt><code>*</code></dt> |
| 822 <dd>if no default namespace has been specified, this is equivalent to *|*. |
| 823 Otherwise it is equivalent to ns|* where ns is the default namespace.</dd> |
| 824 </dl> |
| 825 |
| 826 <p>A universal selector containing a namespace prefix that has not |
| 827 been previously declared is an <a href="#Conformance">invalid</a> |
| 828 selector. The mechanism for declaring a namespace prefix is left up |
| 829 to the language implementing Selectors. In CSS, such a mechanism is |
| 830 defined in the General Syntax module.</p> |
| 831 |
| 832 |
| 833 <h3><a name=attribute-selectors>6.3. Attribute selectors</a></h3> |
| 834 |
| 835 <p>Selectors allow the representation of an element's attributes. When |
| 836 a selector is used as an expression to match against an element, |
| 837 attribute selectors must be considered to match an element if that |
| 838 element has an attribute that matches the attribute represented by the |
| 839 attribute selector.</p> |
| 840 |
| 841 <h4><a name=attribute-representation>6.3.1. Attribute presence and values |
| 842 selectors</a></h4> |
| 843 |
| 844 <p>CSS2 introduced four attribute selectors:</p> |
| 845 |
| 846 <dl> |
| 847 <dt><code>[att]</code> |
| 848 <dd>Represents an element with the <code>att</code> attribute, whatever the va
lue of |
| 849 the attribute.</dd> |
| 850 <dt><code>[att=val]</code></dt> |
| 851 <dd>Represents an element with the <code>att</code> attribute whose value is e
xactly |
| 852 "val".</dd> |
| 853 <dt><code>[att~=val]</code></dt> |
| 854 <dd>Represents an element with the <code>att</code> attribute whose value is a
<a |
| 855 href="#whitespace">whitespace</a>-separated list of words, one of |
| 856 which is exactly "val". If "val" contains whitespace, it will never |
| 857 represent anything (since the words are <em>separated</em> by |
| 858 spaces).</dd> |
| 859 <dt><code>[att|=val]</code> |
| 860 <dd>Represents an element with the <code>att</code> attribute, its value eithe
r |
| 861 being exactly "val" or beginning with "val" immediately followed by |
| 862 "-" (U+002D). This is primarily intended to allow language subcode |
| 863 matches (e.g., the <code>hreflang</code> attribute on the |
| 864 <code>link</code> element in HTML) as described in RFC 3066 (<a |
| 865 href="#refsRFC3066">[RFC3066]</a>). For <code>lang</code> (or |
| 866 <code>xml:lang</code>) language subcode matching, please see <a |
| 867 href="#lang-pseudo">the <code>:lang</code> pseudo-class</a>.</dd> |
| 868 </dl> |
| 869 |
| 870 <p>Attribute values must be identifiers or strings. The |
| 871 case-sensitivity of attribute names and values in selectors depends on |
| 872 the document language.</p> |
| 873 |
| 874 <div class="example"> |
| 875 |
| 876 <p>Examples:</p> |
| 877 |
| 878 <p>The following attribute selector represents an <code>h1</code> |
| 879 element that carries the <code>title</code> attribute, whatever its |
| 880 value:</p> |
| 881 |
| 882 <pre>h1[title]</pre> |
| 883 |
| 884 <p>In the following example, the selector represents a |
| 885 <code>span</code> element whose <code>class</code> attribute has |
| 886 exactly the value "example":</p> |
| 887 |
| 888 <pre>span[class="example"]</pre> |
| 889 |
| 890 <p>Multiple attribute selectors can be used to represent several |
| 891 attributes of an element, or several conditions on the same |
| 892 attribute. Here, the selector represents a <code>span</code> element |
| 893 whose <code>hello</code> attribute has exactly the value "Cleveland" |
| 894 and whose <code>goodbye</code> attribute has exactly the value |
| 895 "Columbus":</p> |
| 896 |
| 897 <pre>span[hello="Cleveland"][goodbye="Columbus"]</pre> |
| 898 |
| 899 <p>The following selectors illustrate the differences between "=" |
| 900 and "~=". The first selector will represent, for example, the value |
| 901 "copyright copyleft copyeditor" on a <code>rel</code> attribute. The |
| 902 second selector will only represent an <code>a</code> element with |
| 903 an <code>href</code> attribute having the exact value |
| 904 "http://www.w3.org/".</p> |
| 905 |
| 906 <pre>a[rel~="copyright"] |
| 907 a[href="http://www.w3.org/"]</pre> |
| 908 |
| 909 <p>The following selector represents a <code>link</code> element |
| 910 whose <code>hreflang</code> attribute is exactly "fr".</p> |
| 911 |
| 912 <pre>link[hreflang=fr]</pre> |
| 913 |
| 914 <p>The following selector represents a <code>link</code> element for |
| 915 which the values of the <code>hreflang</code> attribute begins with |
| 916 "en", including "en", "en-US", and "en-cockney":</p> |
| 917 |
| 918 <pre>link[hreflang|="en"]</pre> |
| 919 |
| 920 <p>Similarly, the following selectors represents a |
| 921 <code>DIALOGUE</code> element whenever it has one of two different |
| 922 values for an attribute <code>character</code>:</p> |
| 923 |
| 924 <pre>DIALOGUE[character=romeo] |
| 925 DIALOGUE[character=juliet]</pre> |
| 926 |
| 927 </div> |
| 928 |
| 929 <h4><a name=attribute-substrings></a>6.3.2. Substring matching attribute |
| 930 selectors</h4> |
| 931 |
| 932 <p>Three additional attribute selectors are provided for matching |
| 933 substrings in the value of an attribute:</p> |
| 934 |
| 935 <dl> |
| 936 <dt><code>[att^=val]</code></dt> |
| 937 <dd>Represents an element with the <code>att</code> attribute whose value begi
ns |
| 938 with the prefix "val".</dd> |
| 939 <dt><code>[att$=val]</code> |
| 940 <dd>Represents an element with the <code>att</code> attribute whose value ends
with |
| 941 the suffix "val".</dd> |
| 942 <dt><code>[att*=val]</code> |
| 943 <dd>Represents an element with the <code>att</code> attribute whose value cont
ains |
| 944 at least one instance of the substring "val".</dd> |
| 945 </dl> |
| 946 |
| 947 <p>Attribute values must be identifiers or strings. The |
| 948 case-sensitivity of attribute names in selectors depends on the |
| 949 document language.</p> |
| 950 |
| 951 <div class="example"> |
| 952 <p>Examples:</p> |
| 953 <p>The following selector represents an HTML <code>object</code>, referencing a
n |
| 954 image:</p> |
| 955 <pre>object[type^="image/"]</pre> |
| 956 <p>The following selector represents an HTML anchor <code>a</code> with an |
| 957 <code>href</code> attribute whose value ends with ".html".</p> |
| 958 <pre>a[href$=".html"]</pre> |
| 959 <p>The following selector represents an HTML paragraph with a <code>title</code
> |
| 960 attribute whose value contains the substring "hello"</p> |
| 961 <pre>p[title*="hello"]</pre> |
| 962 </div> |
| 963 |
| 964 <h4><a name=attrnmsp>6.3.3. Attribute selectors and namespaces</a></h4> |
| 965 |
| 966 <p>Attribute selectors allow an optional namespace component to the |
| 967 attribute name. A namespace prefix that has been previously declared |
| 968 may be prepended to the attribute name separated by the namespace |
| 969 separator "vertical bar" (<code>|</code>). In keeping with |
| 970 the Namespaces in the XML recommendation, default namespaces do not |
| 971 apply to attributes, therefore attribute selectors without a namespace |
| 972 component apply only to attributes that have no declared namespace |
| 973 (equivalent to "<code>|attr</code>"). An asterisk may be used for the |
| 974 namespace prefix indicating that the selector is to match all |
| 975 attribute names without regard to the attribute's namespace. |
| 976 |
| 977 <p>An attribute selector with an attribute name containing a namespace |
| 978 prefix that has not been previously declared is an <a |
| 979 href="#Conformance">invalid</a> selector. The mechanism for declaring |
| 980 a namespace prefix is left up to the language implementing Selectors. |
| 981 In CSS, such a mechanism is defined in the General Syntax module. |
| 982 |
| 983 <div class="example"> |
| 984 <p>CSS examples:</p> |
| 985 <pre>@namespace foo "http://www.example.com"; |
| 986 [foo|att=val] { color: blue } |
| 987 [*|att] { color: yellow } |
| 988 [|att] { color: green } |
| 989 [att] { color: green }</pre> |
| 990 |
| 991 <p>The first rule will match only elements with the attribute |
| 992 <code>att</code> in the "http://www.example.com" namespace with the |
| 993 value "val".</p> |
| 994 |
| 995 <p>The second rule will match only elements with the attribute |
| 996 <code>att</code> regardless of the namespace of the attribute |
| 997 (including no declared namespace).</p> |
| 998 |
| 999 <p>The last two rules are equivalent and will match only elements |
| 1000 with the attribute <code>att</code> where the attribute is not |
| 1001 declared to be in a namespace.</p> |
| 1002 |
| 1003 </div> |
| 1004 |
| 1005 <h4><a name=def-values>6.3.4. Default attribute values in DTDs</a></h4> |
| 1006 |
| 1007 <p>Attribute selectors represent explicitly set attribute values in |
| 1008 the document tree. Default attribute values may be defined in a DTD or |
| 1009 elsewhere, but cannot always be selected by attribute |
| 1010 selectors. Selectors should be designed so that they work even if the |
| 1011 default values are not included in the document tree.</p> |
| 1012 |
| 1013 <p>More precisely, a UA is <em>not</em> required to read an "external |
| 1014 subset" of the DTD but <em>is</em> required to look for default |
| 1015 attribute values in the document's "internal subset." (See <a |
| 1016 href="#refsXML10">[XML10]</a> for definitions of these subsets.)</p> |
| 1017 |
| 1018 <p>A UA that recognizes an XML namespace <a |
| 1019 href="#refsXMLNAMES">[XMLNAMES]</a> is not required to use its |
| 1020 knowledge of that namespace to treat default attribute values as if |
| 1021 they were present in the document. (For example, an XHTML UA is not |
| 1022 required to use its built-in knowledge of the XHTML DTD.)</p> |
| 1023 |
| 1024 <p class="note"><strong>Note:</strong> Typically, implementations |
| 1025 choose to ignore external subsets.</p> |
| 1026 |
| 1027 <div class="example"> |
| 1028 <p>Example:</p> |
| 1029 |
| 1030 <p>Consider an element EXAMPLE with an attribute "notation" that has a |
| 1031 default value of "decimal". The DTD fragment might be</p> |
| 1032 |
| 1033 <pre class="dtd-example"><!ATTLIST EXAMPLE notation (decimal,octal) "decimal"
></pre> |
| 1034 |
| 1035 <p>If the style sheet contains the rules</p> |
| 1036 |
| 1037 <pre>EXAMPLE[notation=decimal] { /*... default property settings ...*/ } |
| 1038 EXAMPLE[notation=octal] { /*... other settings...*/ }</pre> |
| 1039 |
| 1040 <p>the first rule will not match elements whose "notation" attribute |
| 1041 is set by default, i.e. not set explicitly. To catch all cases, the |
| 1042 attribute selector for the default value must be dropped:</p> |
| 1043 |
| 1044 <pre>EXAMPLE { /*... default property settings ...*/ } |
| 1045 EXAMPLE[notation=octal] { /*... other settings...*/ }</pre> |
| 1046 |
| 1047 <p>Here, because the selector <code>EXAMPLE[notation=octal]</code> is |
| 1048 more specific than the tag |
| 1049 selector alone, the style declarations in the second rule will override |
| 1050 those in the first for elements that have a "notation" attribute value |
| 1051 of "octal". Care has to be taken that all property declarations that |
| 1052 are to apply only to the default case are overridden in the non-default |
| 1053 cases' style rules.</p> |
| 1054 |
| 1055 </div> |
| 1056 |
| 1057 <h3><a name=class-html>6.4. Class selectors</a></h3> |
| 1058 |
| 1059 <p>Working with HTML, authors may use the period (U+002E, |
| 1060 <code>.</code>) notation as an alternative to the <code>~=</code> |
| 1061 notation when representing the <code>class</code> attribute. Thus, for |
| 1062 HTML, <code>div.value</code> and <code>div[class~=value]</code> have |
| 1063 the same meaning. The attribute value must immediately follow the |
| 1064 "period" (<code>.</code>).</p> |
| 1065 |
| 1066 <p>UAs may apply selectors using the period (.) notation in XML |
| 1067 documents if the UA has namespace-specific knowledge that allows it to |
| 1068 determine which attribute is the "class" attribute for the |
| 1069 respective namespace. One such example of namespace-specific knowledge |
| 1070 is the prose in the specification for a particular namespace (e.g. SVG |
| 1071 1.0 <a href="#refsSVG">[SVG]</a> describes the <a |
| 1072 href="http://www.w3.org/TR/2001/PR-SVG-20010719/styling.html#ClassAttribute">SVG |
| 1073 "class" attribute</a> and how a UA should interpret it, and |
| 1074 similarly MathML 1.01 <a href="#refsMATH">[MATH]</a> describes the <a |
| 1075 href="http://www.w3.org/1999/07/REC-MathML-19990707/chapter2.html#sec2.3.4">Math
ML |
| 1076 "class" attribute</a>.)</p> |
| 1077 |
| 1078 <div class="example"> |
| 1079 <p>CSS examples:</p> |
| 1080 |
| 1081 <p>We can assign style information to all elements with |
| 1082 <code>class~="pastoral"</code> as follows:</p> |
| 1083 |
| 1084 <pre>*.pastoral { color: green } /* all elements with class~=pastoral */</pre
> |
| 1085 |
| 1086 <p>or just</p> |
| 1087 |
| 1088 <pre>.pastoral { color: green } /* all elements with class~=pastoral */</pre> |
| 1089 |
| 1090 <p>The following assigns style only to H1 elements with |
| 1091 <code>class~="pastoral"</code>:</p> |
| 1092 |
| 1093 <pre>H1.pastoral { color: green } /* H1 elements with class~=pastoral */</pre
> |
| 1094 |
| 1095 <p>Given these rules, the first H1 instance below would not have |
| 1096 green text, while the second would:</p> |
| 1097 |
| 1098 <pre><H1>Not green</H1> |
| 1099 <H1 class="pastoral">Very green</H1></pre> |
| 1100 |
| 1101 </div> |
| 1102 |
| 1103 <p>To represent a subset of "class" values, each value must be preceded |
| 1104 by a ".", in any order.</P> |
| 1105 |
| 1106 <div class="example"> |
| 1107 |
| 1108 <p>CSS example:</p> |
| 1109 |
| 1110 <p>The following rule matches any P element whose "class" attribute |
| 1111 has been assigned a list of <a |
| 1112 href="#whitespace">whitespace</a>-separated values that includes |
| 1113 "pastoral" and "marine":</p> |
| 1114 |
| 1115 <pre>p.pastoral.marine { color: green }</pre> |
| 1116 |
| 1117 <p>This rule matches when <code>class="pastoral blue aqua |
| 1118 marine"</code> but does not match for <code>class="pastoral |
| 1119 blue"</code>.</p> |
| 1120 |
| 1121 </div> |
| 1122 |
| 1123 <p class="note"><strong>Note:</strong> Because CSS gives considerable |
| 1124 power to the "class" attribute, authors could conceivably design their |
| 1125 own "document language" based on elements with almost no associated |
| 1126 presentation (such as DIV and SPAN in HTML) and assigning style |
| 1127 information through the "class" attribute. Authors should avoid this |
| 1128 practice since the structural elements of a document language often |
| 1129 have recognized and accepted meanings and author-defined classes may |
| 1130 not.</p> |
| 1131 |
| 1132 <p class="note"><strong>Note:</strong> If an element has multiple |
| 1133 class attributes, their values must be concatenated with spaces |
| 1134 between the values before searching for the class. As of this time the |
| 1135 working group is not aware of any manner in which this situation can |
| 1136 be reached, however, so this behavior is explicitly non-normative in |
| 1137 this specification.</p> |
| 1138 |
| 1139 <h3><a name=id-selectors>6.5. ID selectors</a></h3> |
| 1140 |
| 1141 <p>Document languages may contain attributes that are declared to be |
| 1142 of type ID. What makes attributes of type ID special is that no two |
| 1143 such attributes can have the same value in a document, regardless of |
| 1144 the type of the elements that carry them; whatever the document |
| 1145 language, an ID typed attribute can be used to uniquely identify its |
| 1146 element. In HTML all ID attributes are named "id"; XML applications |
| 1147 may name ID attributes differently, but the same restriction |
| 1148 applies.</p> |
| 1149 |
| 1150 <p>An ID-typed attribute of a document language allows authors to |
| 1151 assign an identifier to one element instance in the document tree. W3C |
| 1152 ID selectors represent an element instance based on its identifier. An |
| 1153 ID selector contains a "number sign" (U+0023, |
| 1154 <code>#</code>) immediately followed by the ID value, which must be an |
| 1155 identifier.</p> |
| 1156 |
| 1157 <p>Selectors does not specify how a UA knows the ID-typed attribute of |
| 1158 an element. The UA may, e.g., read a document's DTD, have the |
| 1159 information hard-coded or ask the user. |
| 1160 |
| 1161 <div class="example"> |
| 1162 <p>Examples:</p> |
| 1163 <p>The following ID selector represents an <code>h1</code> element |
| 1164 whose ID-typed attribute has the value "chapter1":</p> |
| 1165 <pre>h1#chapter1</pre> |
| 1166 <p>The following ID selector represents any element whose ID-typed |
| 1167 attribute has the value "chapter1":</p> |
| 1168 <pre>#chapter1</pre> |
| 1169 <p>The following selector represents any element whose ID-typed |
| 1170 attribute has the value "z98y".</p> |
| 1171 <pre>*#z98y</pre> |
| 1172 </div> |
| 1173 |
| 1174 <p class="note"><strong>Note.</strong> In XML 1.0 <a |
| 1175 href="#refsXML10">[XML10]</a>, the information about which attribute |
| 1176 contains an element's IDs is contained in a DTD or a schema. When |
| 1177 parsing XML, UAs do not always read the DTD, and thus may not know |
| 1178 what the ID of an element is (though a UA may have namespace-specific |
| 1179 knowledge that allows it to determine which attribute is the ID |
| 1180 attribute for that namespace). If a style sheet designer knows or |
| 1181 suspects that a UA may not know what the ID of an element is, he |
| 1182 should use normal attribute selectors instead: |
| 1183 <code>[name=p371]</code> instead of <code>#p371</code>. Elements in |
| 1184 XML 1.0 documents without a DTD do not have IDs at all.</p> |
| 1185 |
| 1186 <p>If an element has multiple ID attributes, all of them must be |
| 1187 treated as IDs for that element for the purposes of the ID |
| 1188 selector. Such a situation could be reached using mixtures of xml:id, |
| 1189 DOM3 Core, XML DTDs, and namespace-specific knowledge.</p> |
| 1190 |
| 1191 <h3><a name=pseudo-classes>6.6. Pseudo-classes</a></h3> |
| 1192 |
| 1193 <p>The pseudo-class concept is introduced to permit selection based on |
| 1194 information that lies outside of the document tree or that cannot be |
| 1195 expressed using the other simple selectors.</p> |
| 1196 |
| 1197 <p>A pseudo-class always consists of a "colon" |
| 1198 (<code>:</code>) followed by the name of the pseudo-class and |
| 1199 optionally by a value between parentheses.</p> |
| 1200 |
| 1201 <p>Pseudo-classes are allowed in all sequences of simple selectors |
| 1202 contained in a selector. Pseudo-classes are allowed anywhere in |
| 1203 sequences of simple selectors, after the leading type selector or |
| 1204 universal selector (possibly omitted). Pseudo-class names are |
| 1205 case-insensitive. Some pseudo-classes are mutually exclusive, while |
| 1206 others can be applied simultaneously to the same |
| 1207 element. Pseudo-classes may be dynamic, in the sense that an element |
| 1208 may acquire or lose a pseudo-class while a user interacts with the |
| 1209 document.</p> |
| 1210 |
| 1211 |
| 1212 <h4><a name=dynamic-pseudos>6.6.1. Dynamic pseudo-classes</a></h4> |
| 1213 |
| 1214 <p>Dynamic pseudo-classes classify elements on characteristics other |
| 1215 than their name, attributes, or content, in principle characteristics |
| 1216 that cannot be deduced from the document tree.</p> |
| 1217 |
| 1218 <p>Dynamic pseudo-classes do not appear in the document source or |
| 1219 document tree.</p> |
| 1220 |
| 1221 |
| 1222 <h5>The <a name=link>link pseudo-classes: :link and :visited</a></h5> |
| 1223 |
| 1224 <p>User agents commonly display unvisited links differently from |
| 1225 previously visited ones. Selectors |
| 1226 provides the pseudo-classes <code>:link</code> and |
| 1227 <code>:visited</code> to distinguish them:</p> |
| 1228 |
| 1229 <ul> |
| 1230 <li>The <code>:link</code> pseudo-class applies to links that have |
| 1231 not yet been visited.</li> |
| 1232 <li>The <code>:visited</code> pseudo-class applies once the link has |
| 1233 been visited by the user. </li> |
| 1234 </ul> |
| 1235 |
| 1236 <p>After some amount of time, user agents may choose to return a |
| 1237 visited link to the (unvisited) ':link' state.</p> |
| 1238 |
| 1239 <p>The two states are mutually exclusive.</p> |
| 1240 |
| 1241 <div class="example"> |
| 1242 |
| 1243 <p>Example:</p> |
| 1244 |
| 1245 <p>The following selector represents links carrying class |
| 1246 <code>external</code> and already visited:</p> |
| 1247 |
| 1248 <pre>a.external:visited</pre> |
| 1249 |
| 1250 </div> |
| 1251 |
| 1252 <p class="note"><strong>Note:</strong> It is possible for style sheet |
| 1253 authors to abuse the :link and :visited pseudo-classes to determine |
| 1254 which sites a user has visited without the user's consent. |
| 1255 |
| 1256 <p>UAs may therefore treat all links as unvisited links, or implement |
| 1257 other measures to preserve the user's privacy while rendering visited |
| 1258 and unvisited links differently.</p> |
| 1259 |
| 1260 <h5>The <a name=useraction-pseudos>user action pseudo-classes |
| 1261 :hover, :active, and :focus</a></h5> |
| 1262 |
| 1263 <p>Interactive user agents sometimes change the rendering in response |
| 1264 to user actions. Selectors provides |
| 1265 three pseudo-classes for the selection of an element the user is |
| 1266 acting on.</p> |
| 1267 |
| 1268 <ul> |
| 1269 |
| 1270 <li>The <code>:hover</code> pseudo-class applies while the user |
| 1271 designates an element with a pointing device, but does not activate |
| 1272 it. For example, a visual user agent could apply this pseudo-class |
| 1273 when the cursor (mouse pointer) hovers over a box generated by the |
| 1274 element. User agents not that do not support <a |
| 1275 href="http://www.w3.org/TR/REC-CSS2/media.html#interactive-media-group">intera
ctive |
| 1276 media</a> do not have to support this pseudo-class. Some conforming |
| 1277 user agents that support <a |
| 1278 href="http://www.w3.org/TR/REC-CSS2/media.html#interactive-media-group">intera
ctive |
| 1279 media</a> may not be able to support this pseudo-class (e.g., a pen |
| 1280 device that does not detect hovering).</li> |
| 1281 |
| 1282 <li>The <code>:active</code> pseudo-class applies while an element |
| 1283 is being activated by the user. For example, between the times the |
| 1284 user presses the mouse button and releases it.</li> |
| 1285 |
| 1286 <li>The <code>:focus</code> pseudo-class applies while an element |
| 1287 has the focus (accepts keyboard or mouse events, or other forms of |
| 1288 input). </li> |
| 1289 |
| 1290 </ul> |
| 1291 |
| 1292 <p>There may be document language or implementation specific limits on |
| 1293 which elements can become <code>:active</code> or acquire |
| 1294 <code>:focus</code>.</p> |
| 1295 |
| 1296 <p>These pseudo-classes are not mutually exclusive. An element may |
| 1297 match several pseudo-classes at the same time.</p> |
| 1298 |
| 1299 <p>Selectors doesn't define if the parent of an element that is |
| 1300 ':active' or ':hover' is also in that state.</p> |
| 1301 |
| 1302 <div class="example"> |
| 1303 <p>Examples:</p> |
| 1304 <pre>a:link /* unvisited links */ |
| 1305 a:visited /* visited links */ |
| 1306 a:hover /* user hovers */ |
| 1307 a:active /* active links */</pre> |
| 1308 <p>An example of combining dynamic pseudo-classes:</p> |
| 1309 <pre>a:focus |
| 1310 a:focus:hover</pre> |
| 1311 <p>The last selector matches <code>a</code> elements that are in |
| 1312 the pseudo-class :focus and in the pseudo-class :hover.</p> |
| 1313 </div> |
| 1314 |
| 1315 <p class="note"><strong>Note:</strong> An element can be both ':visited' |
| 1316 and ':active' (or ':link' and ':active').</p> |
| 1317 |
| 1318 <h4><a name=target-pseudo>6.6.2. The target pseudo-class :target</a></h4> |
| 1319 |
| 1320 <p>Some URIs refer to a location within a resource. This kind of URI |
| 1321 ends with a "number sign" (#) followed by an anchor |
| 1322 identifier (called the fragment identifier).</p> |
| 1323 |
| 1324 <p>URIs with fragment identifiers link to a certain element within the |
| 1325 document, known as the target element. For instance, here is a URI |
| 1326 pointing to an anchor named <code>section_2</code> in an HTML |
| 1327 document:</p> |
| 1328 |
| 1329 <pre>http://example.com/html/top.html#section_2</pre> |
| 1330 |
| 1331 <p>A target element can be represented by the <code>:target</code> |
| 1332 pseudo-class. If the document's URI has no fragment identifier, then |
| 1333 the document has no target element.</p> |
| 1334 |
| 1335 <div class="example"> |
| 1336 <p>Example:</p> |
| 1337 <pre>p.note:target</pre> |
| 1338 <p>This selector represents a <code>p</code> element of class |
| 1339 <code>note</code> that is the target element of the referring |
| 1340 URI.</p> |
| 1341 </div> |
| 1342 |
| 1343 <div class="example"> |
| 1344 <p>CSS example:</p> |
| 1345 <p>Here, the <code>:target</code> pseudo-class is used to make the |
| 1346 target element red and place an image before it, if there is one:</p> |
| 1347 <pre>*:target { color : red } |
| 1348 *:target::before { content : url(target.png) }</pre> |
| 1349 </div> |
| 1350 |
| 1351 <h4><a name=lang-pseudo>6.6.3. The language pseudo-class :lang</a></h4> |
| 1352 |
| 1353 <p>If the document language specifies how the human language of an |
| 1354 element is determined, it is possible to write selectors that |
| 1355 represent an element based on its language. For example, in HTML <a |
| 1356 href="#refsHTML4">[HTML4]</a>, the language is determined by a |
| 1357 combination of the <code>lang</code> attribute, the <code>meta</code> |
| 1358 element, and possibly by information from the protocol (such as HTTP |
| 1359 headers). XML uses an attribute called <code>xml:lang</code>, and |
| 1360 there may be other document language-specific methods for determining |
| 1361 the language.</p> |
| 1362 |
| 1363 <p>The pseudo-class <code>:lang(C)</code> represents an element that |
| 1364 is in language C. Whether an element is represented by a |
| 1365 <code>:lang()</code> selector is based solely on the identifier C |
| 1366 being either equal to, or a hyphen-separated substring of, the |
| 1367 element's language value, in the same way as if performed by the <a |
| 1368 href="#attribute-representation">'|='</a> operator in attribute |
| 1369 selectors. The identifier C does not have to be a valid language |
| 1370 name.</p> |
| 1371 |
| 1372 <p>C must not be empty. (If it is, the selector is invalid.)</p> |
| 1373 |
| 1374 <p class="note"><strong>Note:</strong> It is recommended that |
| 1375 documents and protocols indicate language using codes from RFC 3066 <a |
| 1376 href="#refsRFC3066">[RFC3066]</a> or its successor, and by means of |
| 1377 "xml:lang" attributes in the case of XML-based documents <a |
| 1378 href="#refsXML10">[XML10]</a>. See <a |
| 1379 href="http://www.w3.org/International/questions/qa-lang-2or3.html"> |
| 1380 "FAQ: Two-letter or three-letter language codes."</a></p> |
| 1381 |
| 1382 <div class="example"> |
| 1383 <p>Examples:</p> |
| 1384 <p>The two following selectors represent an HTML document that is in |
| 1385 Belgian, French, or German. The two next selectors represent |
| 1386 <code>q</code> quotations in an arbitrary element in Belgian, French, |
| 1387 or German.</p> |
| 1388 <pre>html:lang(fr-be) |
| 1389 html:lang(de) |
| 1390 :lang(fr-be) > q |
| 1391 :lang(de) > q</pre> |
| 1392 </div> |
| 1393 |
| 1394 <h4><a name=UIstates>6.6.4. The UI element states pseudo-classes</a></h4> |
| 1395 |
| 1396 <h5><a name=enableddisabled>The :enabled and :disabled pseudo-classes</a></h5> |
| 1397 |
| 1398 <p>The <code>:enabled</code> pseudo-class allows authors to customize |
| 1399 the look of user interface elements that are enabled — which the |
| 1400 user can select or activate in some fashion (e.g. clicking on a button |
| 1401 with a mouse). There is a need for such a pseudo-class because there |
| 1402 is no way to programmatically specify the default appearance of say, |
| 1403 an enabled <code>input</code> element without also specifying what it |
| 1404 would look like when it was disabled.</p> |
| 1405 |
| 1406 <p>Similar to <code>:enabled</code>, <code>:disabled</code> allows the |
| 1407 author to specify precisely how a disabled or inactive user interface |
| 1408 element should look.</p> |
| 1409 |
| 1410 <p>Most elements will be neither enabled nor disabled. An element is |
| 1411 enabled if the user can either activate it or transfer the focus to |
| 1412 it. An element is disabled if it could be enabled, but the user cannot |
| 1413 presently activate it or transfer focus to it.</p> |
| 1414 |
| 1415 |
| 1416 <h5><a name=checked>The :checked pseudo-class</a></h5> |
| 1417 |
| 1418 <p>Radio and checkbox elements can be toggled by the user. Some menu |
| 1419 items are "checked" when the user selects them. When such elements are |
| 1420 toggled "on" the <code>:checked</code> pseudo-class applies. The |
| 1421 <code>:checked</code> pseudo-class initially applies to such elements |
| 1422 that have the HTML4 <code>selected</code> and <code>checked</code> |
| 1423 attributes as described in <a |
| 1424 href="http://www.w3.org/TR/REC-html40/interact/forms.html#h-17.2.1">Section |
| 1425 17.2.1 of HTML4</a>, but of course the user can toggle "off" such |
| 1426 elements in which case the <code>:checked</code> pseudo-class would no |
| 1427 longer apply. While the <code>:checked</code> pseudo-class is dynamic |
| 1428 in nature, and is altered by user action, since it can also be based |
| 1429 on the presence of the semantic HTML4 <code>selected</code> and |
| 1430 <code>checked</code> attributes, it applies to all media. |
| 1431 |
| 1432 |
| 1433 <h5><a name=indeterminate>The :indeterminate pseudo-class</a></h5> |
| 1434 |
| 1435 <div class="note"> |
| 1436 |
| 1437 <p>Radio and checkbox elements can be toggled by the user, but are |
| 1438 sometimes in an indeterminate state, neither checked nor unchecked. |
| 1439 This can be due to an element attribute, or DOM manipulation.</p> |
| 1440 |
| 1441 <p>A future version of this specification may introduce an |
| 1442 <code>:indeterminate</code> pseudo-class that applies to such elements. |
| 1443 <!--While the <code>:indeterminate</code> pseudo-class is dynamic in |
| 1444 nature, and is altered by user action, since it can also be based on |
| 1445 the presence of an element attribute, it applies to all media.</p> |
| 1446 |
| 1447 <p>Components of a radio-group initialized with no pre-selected choice |
| 1448 are an example of :indeterminate state.--></p> |
| 1449 |
| 1450 </div> |
| 1451 |
| 1452 |
| 1453 <h4><a name=structural-pseudos>6.6.5. Structural pseudo-classes</a></h4> |
| 1454 |
| 1455 <p>Selectors introduces the concept of <dfn>structural |
| 1456 pseudo-classes</dfn> to permit selection based on extra information that lies in |
| 1457 the document tree but cannot be represented by other simple selectors or |
| 1458 combinators. |
| 1459 |
| 1460 <p>Note that standalone pieces of PCDATA (text nodes in the DOM) are |
| 1461 not counted when calculating the position of an element in the list of |
| 1462 children of its parent. When calculating the position of an element in |
| 1463 the list of children of its parent, the index numbering starts at 1. |
| 1464 |
| 1465 |
| 1466 <h5><a name=root-pseudo>:root pseudo-class</a></h5> |
| 1467 |
| 1468 <p>The <code>:root</code> pseudo-class represents an element that is |
| 1469 the root of the document. In HTML 4, this is always the |
| 1470 <code>HTML</code> element. |
| 1471 |
| 1472 |
| 1473 <h5><a name=nth-child-pseudo>:nth-child() pseudo-class</a></h5> |
| 1474 |
| 1475 <p>The |
| 1476 <code>:nth-child(<var>a</var><code>n</code>+<var>b</var>)</code> |
| 1477 pseudo-class notation represents an element that has |
| 1478 <var>a</var><code>n</code>+<var>b</var>-1 siblings |
| 1479 <strong>before</strong> it in the document tree, for a given positive |
| 1480 integer or zero value of <code>n</code>, and has a parent element. In |
| 1481 other words, this matches the <var>b</var>th child of an element after |
| 1482 all the children have been split into groups of <var>a</var> elements |
| 1483 each. For example, this allows the selectors to address every other |
| 1484 row in a table, and could be used to alternate the color |
| 1485 of paragraph text in a cycle of four. The <var>a</var> and |
| 1486 <var>b</var> values must be zero, negative integers or positive |
| 1487 integers. The index of the first child of an element is 1. |
| 1488 |
| 1489 <p>In addition to this, <code>:nth-child()</code> can take |
| 1490 '<code>odd</code>' and '<code>even</code>' as arguments instead. |
| 1491 '<code>odd</code>' has the same signification as <code>2n+1</code>, |
| 1492 and '<code>even</code>' has the same signification as <code>2n</code>. |
| 1493 |
| 1494 |
| 1495 <div class="example"> |
| 1496 <p>Examples:</p> |
| 1497 <pre>tr:nth-child(2n+1) /* represents every odd row of an HTML table */ |
| 1498 tr:nth-child(odd) /* same */ |
| 1499 tr:nth-child(2n) /* represents every even row of an HTML table */ |
| 1500 tr:nth-child(even) /* same */ |
| 1501 |
| 1502 /* Alternate paragraph colours in CSS */ |
| 1503 p:nth-child(4n+1) { color: navy; } |
| 1504 p:nth-child(4n+2) { color: green; } |
| 1505 p:nth-child(4n+3) { color: maroon; } |
| 1506 p:nth-child(4n+4) { color: purple; }</pre> |
| 1507 </div> |
| 1508 |
| 1509 <p>When <var>a</var>=0, no repeating is used, so for example |
| 1510 <code>:nth-child(0n+5)</code> matches only the fifth child. When |
| 1511 <var>a</var>=0, the <var>a</var><code>n</code> part need not be |
| 1512 included, so the syntax simplifies to |
| 1513 <code>:nth-child(<var>b</var>)</code> and the last example simplifies |
| 1514 to <code>:nth-child(5)</code>. |
| 1515 |
| 1516 <div class="example"> |
| 1517 <p>Examples:</p> |
| 1518 <pre>foo:nth-child(0n+1) /* represents an element foo, first child of its pare
nt element */ |
| 1519 foo:nth-child(1) /* same */</pre> |
| 1520 </div> |
| 1521 |
| 1522 <p>When <var>a</var>=1, the number may be omitted from the rule. |
| 1523 |
| 1524 <div class="example"> |
| 1525 <p>Examples:</p> |
| 1526 <p>The following selectors are therefore equivalent:</p> |
| 1527 <pre>bar:nth-child(1n+0) /* represents all bar elements, specificity (0,1,1) *
/ |
| 1528 bar:nth-child(n+0) /* same */ |
| 1529 bar:nth-child(n) /* same */ |
| 1530 bar /* same but lower specificity (0,0,1) */</pre> |
| 1531 </div> |
| 1532 |
| 1533 <p>If <var>b</var>=0, then every <var>a</var>th element is picked. In |
| 1534 such a case, the <var>b</var> part may be omitted. |
| 1535 |
| 1536 <div class="example"> |
| 1537 <p>Examples:</p> |
| 1538 <pre>tr:nth-child(2n+0) /* represents every even row of an HTML table */ |
| 1539 tr:nth-child(2n) /* same */</pre> |
| 1540 </div> |
| 1541 |
| 1542 <p>If both <var>a</var> and <var>b</var> are equal to zero, the |
| 1543 pseudo-class represents no element in the document tree.</p> |
| 1544 |
| 1545 <p>The value <var>a</var> can be negative, but only the positive |
| 1546 values of <var>a</var><code>n</code>+<var>b</var>, for |
| 1547 <code>n</code>≥0, may represent an element in the document |
| 1548 tree.</p> |
| 1549 |
| 1550 <div class="example"> |
| 1551 <p>Example:</p> |
| 1552 <pre>html|tr:nth-child(-n+6) /* represents the 6 first rows of XHTML tables */<
/pre> |
| 1553 </div> |
| 1554 |
| 1555 <p>When the value <var>b</var> is negative, the "+" character in the |
| 1556 expression must be removed (it is effectively replaced by the "-" |
| 1557 character indicating the negative value of <var>b</var>).</p> |
| 1558 |
| 1559 <div class="example"> |
| 1560 <p>Examples:</p> |
| 1561 <pre>:nth-child(10n-1) /* represents the 9th, 19th, 29th, etc, element */ |
| 1562 :nth-child(10n+9) /* Same */ |
| 1563 :nth-child(10n+-1) /* Syntactically invalid, and would be ignored */</pre> |
| 1564 </div> |
| 1565 |
| 1566 |
| 1567 <h5><a name=nth-last-child-pseudo>:nth-last-child() pseudo-class</a></h5> |
| 1568 |
| 1569 <p>The <code>:nth-last-child(<var>a</var>n+<var>b</var>)</code> |
| 1570 pseudo-class notation represents an element that has |
| 1571 <var>a</var><code>n</code>+<var>b</var>-1 siblings |
| 1572 <strong>after</strong> it in the document tree, for a given positive |
| 1573 integer or zero value of <code>n</code>, and has a parent element. See |
| 1574 <code>:nth-child()</code> pseudo-class for the syntax of its argument. |
| 1575 It also accepts the '<code>even</code>' and '<code>odd</code>' values |
| 1576 as arguments. |
| 1577 |
| 1578 |
| 1579 <div class="example"> |
| 1580 <p>Examples:</p> |
| 1581 <pre>tr:nth-last-child(-n+2) /* represents the two last rows of an HTML table
*/ |
| 1582 |
| 1583 foo:nth-last-child(odd) /* represents all odd foo elements in their parent el
ement, |
| 1584 counting from the last one */</pre> |
| 1585 </div> |
| 1586 |
| 1587 |
| 1588 <h5><a name=nth-of-type-pseudo>:nth-of-type() pseudo-class</a></h5> |
| 1589 |
| 1590 <p>The <code>:nth-of-type(<var>a</var>n+<var>b</var>)</code> |
| 1591 pseudo-class notation represents an element that has |
| 1592 <var>a</var><code>n</code>+<var>b</var>-1 siblings with the same |
| 1593 element name <strong>before</strong> it in the document tree, for a |
| 1594 given zero or positive integer value of <code>n</code>, and has a |
| 1595 parent element. In other words, this matches the <var>b</var>th child |
| 1596 of that type after all the children of that type have been split into |
| 1597 groups of a elements each. See <code>:nth-child()</code> pseudo-class |
| 1598 for the syntax of its argument. It also accepts the |
| 1599 '<code>even</code>' and '<code>odd</code>' values. |
| 1600 |
| 1601 |
| 1602 <div class="example"> |
| 1603 <p>CSS example:</p> |
| 1604 <p>This allows an author to alternate the position of floated images:</p> |
| 1605 <pre>img:nth-of-type(2n+1) { float: right; } |
| 1606 img:nth-of-type(2n) { float: left; }</pre> |
| 1607 </div> |
| 1608 |
| 1609 |
| 1610 <h5><a name=nth-last-of-type-pseudo>:nth-last-of-type() pseudo-class</a></h5> |
| 1611 |
| 1612 <p>The <code>:nth-last-of-type(<var>a</var>n+<var>b</var>)</code> |
| 1613 pseudo-class notation represents an element that has |
| 1614 <var>a</var><code>n</code>+<var>b</var>-1 siblings with the same |
| 1615 element name <strong>after</strong> it in the document tree, for a |
| 1616 given zero or positive integer value of <code>n</code>, and has a |
| 1617 parent element. See <code>:nth-child()</code> pseudo-class for the |
| 1618 syntax of its argument. It also accepts the '<code>even</code>' and '<code>odd</
code>' values. |
| 1619 |
| 1620 |
| 1621 <div class="example"> |
| 1622 <p>Example:</p> |
| 1623 <p>To represent all <code>h2</code> children of an XHTML |
| 1624 <code>body</code> except the first and last, one could use the |
| 1625 following selector:</p> |
| 1626 <pre>body > h2:nth-of-type(n+2):nth-last-of-type(n+2)</pre> |
| 1627 <p>In this case, one could also use <code>:not()</code>, although the |
| 1628 selector ends up being just as long:</p> |
| 1629 <pre>body > h2:not(:first-of-type):not(:last-of-type)</pre> |
| 1630 </div> |
| 1631 |
| 1632 |
| 1633 <h5><a name=first-child-pseudo>:first-child pseudo-class</a></h5> |
| 1634 |
| 1635 <p>Same as <code>:nth-child(1)</code>. The <code>:first-child</code> pseudo-clas
s |
| 1636 represents an element that is the first child of some other element. |
| 1637 |
| 1638 |
| 1639 <div class="example"> |
| 1640 <p>Examples:</p> |
| 1641 <p>The following selector represents a <code>p</code> element that is |
| 1642 the first child of a <code>div</code> element:</p> |
| 1643 <pre>div > p:first-child</pre> |
| 1644 <p>This selector can represent the <code>p</code> inside the |
| 1645 <code>div</code> of the following fragment:</p> |
| 1646 <pre><p> The last P before the note.</p> |
| 1647 <div class="note"> |
| 1648 <p> The first P inside the note.</p> |
| 1649 </div></pre>but cannot represent the second <code>p</code> in the followin
g |
| 1650 fragment: |
| 1651 <pre><p> The last P before the note.</p> |
| 1652 <div class="note"> |
| 1653 <h2> Note </h2> |
| 1654 <p> The first P inside the note.</p> |
| 1655 </div></pre> |
| 1656 <p>The following two selectors are usually equivalent:</p> |
| 1657 <pre>* > a:first-child /* a is first child of any element */ |
| 1658 a:first-child /* Same (assuming a is not the root element) */</pre> |
| 1659 </div> |
| 1660 |
| 1661 <h5><a name=last-child-pseudo>:last-child pseudo-class</a></h5> |
| 1662 |
| 1663 <p>Same as <code>:nth-last-child(1)</code>. The <code>:last-child</code> pseudo-
class |
| 1664 represents an element that is the last child of some other element. |
| 1665 |
| 1666 <div class="example"> |
| 1667 <p>Example:</p> |
| 1668 <p>The following selector represents a list item <code>li</code> that |
| 1669 is the last child of an ordered list <code>ol</code>. |
| 1670 <pre>ol > li:last-child</pre> |
| 1671 </div> |
| 1672 |
| 1673 <h5><a name=first-of-type-pseudo>:first-of-type pseudo-class</a></h5> |
| 1674 |
| 1675 <p>Same as <code>:nth-of-type(1)</code>. The <code>:first-of-type</code> pseudo-
class |
| 1676 represents an element that is the first sibling of its type in the list of |
| 1677 children of its parent element. |
| 1678 |
| 1679 <div class="example"> |
| 1680 <p>Example:</p> |
| 1681 <p>The following selector represents a definition title |
| 1682 <code>dt</code> inside a definition list <code>dl</code>, this |
| 1683 <code>dt</code> being the first of its type in the list of children of |
| 1684 its parent element.</p> |
| 1685 <pre>dl dt:first-of-type</pre> |
| 1686 <p>It is a valid description for the first two <code>dt</code> |
| 1687 elements in the following example but not for the third one:</p> |
| 1688 <pre><dl> |
| 1689 <dt>gigogne</dt> |
| 1690 <dd> |
| 1691 <dl> |
| 1692 <dt>fusée</dt> |
| 1693 <dd>multistage rocket</dd> |
| 1694 <dt>table</dt> |
| 1695 <dd>nest of tables</dd> |
| 1696 </dl> |
| 1697 </dd> |
| 1698 </dl></pre> |
| 1699 </div> |
| 1700 |
| 1701 <h5><a name=last-of-type-pseudo>:last-of-type pseudo-class</a></h5> |
| 1702 |
| 1703 <p>Same as <code>:nth-last-of-type(1)</code>. The |
| 1704 <code>:last-of-type</code> pseudo-class represents an element that is |
| 1705 the last sibling of its type in the list of children of its parent |
| 1706 element.</p> |
| 1707 |
| 1708 <div class="example"> |
| 1709 <p>Example:</p> |
| 1710 <p>The following selector represents the last data cell |
| 1711 <code>td</code> of a table row.</p> |
| 1712 <pre>tr > td:last-of-type</pre> |
| 1713 </div> |
| 1714 |
| 1715 <h5><a name=only-child-pseudo>:only-child pseudo-class</a></h5> |
| 1716 |
| 1717 <p>Represents an element that has a parent element and whose parent |
| 1718 element has no other element children. Same as |
| 1719 <code>:first-child:last-child</code> or |
| 1720 <code>:nth-child(1):nth-last-child(1)</code>, but with a lower |
| 1721 specificity.</p> |
| 1722 |
| 1723 <h5><a name=only-of-type-pseudo>:only-of-type pseudo-class</a></h5> |
| 1724 |
| 1725 <p>Represents an element that has a parent element and whose parent |
| 1726 element has no other element children with the same element name. Same |
| 1727 as <code>:first-of-type:last-of-type</code> or |
| 1728 <code>:nth-of-type(1):nth-last-of-type(1)</code>, but with a lower |
| 1729 specificity.</p> |
| 1730 |
| 1731 |
| 1732 <h5><a name=empty-pseudo></a>:empty pseudo-class</h5> |
| 1733 |
| 1734 <p>The <code>:empty</code> pseudo-class represents an element that has |
| 1735 no children at all. In terms of the DOM, only element nodes and text |
| 1736 nodes (including CDATA nodes and entity references) whose data has a |
| 1737 non-zero length must be considered as affecting emptiness; comments, |
| 1738 PIs, and other nodes must not affect whether an element is considered |
| 1739 empty or not.</p> |
| 1740 |
| 1741 <div class="example"> |
| 1742 <p>Examples:</p> |
| 1743 <p><code>p:empty</code> is a valid representation of the following fragment:</p
> |
| 1744 <pre><p></p></pre> |
| 1745 <p><code>foo:empty</code> is not a valid representation for the |
| 1746 following fragments:</p> |
| 1747 <pre><foo>bar</foo></pre> |
| 1748 <pre><foo><bar>bla</bar></foo></pre> |
| 1749 <pre><foo>this is not <bar>:empty</bar></foo></pre> |
| 1750 </div> |
| 1751 |
| 1752 <h4><a name=content-selectors>6.6.6. Blank</a></h4> <!-- It's the Return of Appe
ndix H!!! Run away! --> |
| 1753 |
| 1754 <p>This section intentionally left blank.</p> |
| 1755 <!-- (used to be :contains()) --> |
| 1756 |
| 1757 <h4><a name=negation></a>6.6.7. The negation pseudo-class</h4> |
| 1758 |
| 1759 <p>The negation pseudo-class, <code>:not(<var>X</var>)</code>, is a |
| 1760 functional notation taking a <a href="#simple-selectors-dfn">simple |
| 1761 selector</a> (excluding the negation pseudo-class itself and |
| 1762 pseudo-elements) as an argument. It represents an element that is not |
| 1763 represented by the argument. |
| 1764 |
| 1765 <!-- pseudo-elements are not simple selectors, so the above paragraph |
| 1766 may be a bit confusing --> |
| 1767 |
| 1768 <div class="example"> |
| 1769 <p>Examples:</p> |
| 1770 <p>The following CSS selector matches all <code>button</code> |
| 1771 elements in an HTML document that are not disabled.</p> |
| 1772 <pre>button:not([DISABLED])</pre> |
| 1773 <p>The following selector represents all but <code>FOO</code> |
| 1774 elements.</p> |
| 1775 <pre>*:not(FOO)</pre> |
| 1776 <p>The following group of selectors represents all HTML elements |
| 1777 except links.</p> |
| 1778 <pre>html|*:not(:link):not(:visited)</pre> |
| 1779 </div> |
| 1780 |
| 1781 <p>Default namespace declarations do not affect the argument of the |
| 1782 negation pseudo-class unless the argument is a universal selector or a |
| 1783 type selector.</p> |
| 1784 |
| 1785 <div class="example"> |
| 1786 <p>Examples:</p> |
| 1787 <p>Assuming that the default namespace is bound to |
| 1788 "http://example.com/", the following selector represents all |
| 1789 elements that are not in that namespace:</p> |
| 1790 <pre>*|*:not(*)</pre> |
| 1791 <p>The following CSS selector matches any element being hovered, |
| 1792 regardless of its namespace. In particular, it is not limited to |
| 1793 only matching elements in the default namespace that are not being |
| 1794 hovered, and elements not in the default namespace don't match the |
| 1795 rule when they <em>are</em> being hovered.</p> |
| 1796 <pre>*|*:not(:hover)</pre> |
| 1797 </div> |
| 1798 |
| 1799 <p class="note"><strong>Note</strong>: the :not() pseudo allows |
| 1800 useless selectors to be written. For instance <code>:not(*|*)</code>, |
| 1801 which represents no element at all, or <code>foo:not(bar)</code>, |
| 1802 which is equivalent to <code>foo</code> but with a higher |
| 1803 specificity.</p> |
| 1804 |
| 1805 <h3><a name=pseudo-elements>7. Pseudo-elements</a></h3> |
| 1806 |
| 1807 <p>Pseudo-elements create abstractions about the document tree beyond |
| 1808 those specified by the document language. For instance, document |
| 1809 languages do not offer mechanisms to access the first letter or first |
| 1810 line of an element's content. Pseudo-elements allow designers to refer |
| 1811 to this otherwise inaccessible information. Pseudo-elements may also |
| 1812 provide designers a way to refer to content that does not exist in the |
| 1813 source document (e.g., the <code>::before</code> and |
| 1814 <code>::after</code> pseudo-elements give access to generated |
| 1815 content).</p> |
| 1816 |
| 1817 <p>A pseudo-element is made of two colons (<code>::</code>) followed |
| 1818 by the name of the pseudo-element.</p> |
| 1819 |
| 1820 <p>This <code>::</code> notation is introduced by the current document |
| 1821 in order to establish a discrimination between pseudo-classes and |
| 1822 pseudo-elements. For compatibility with existing style sheets, user |
| 1823 agents must also accept the previous one-colon notation for |
| 1824 pseudo-elements introduced in CSS levels 1 and 2 (namely, |
| 1825 <code>:first-line</code>, <code>:first-letter</code>, |
| 1826 <code>:before</code> and <code>:after</code>). This compatibility is |
| 1827 not allowed for the new pseudo-elements introduced in CSS level 3.</p> |
| 1828 |
| 1829 <p>Only one pseudo-element may appear per selector, and if present it |
| 1830 must appear after the sequence of simple selectors that represents the |
| 1831 <a href="#subject">subjects</a> of the selector. <span class="note">A |
| 1832 future version of this specification may allow multiple |
| 1833 pesudo-elements per selector.</span></p> |
| 1834 |
| 1835 <h4><a name=first-line>7.1. The ::first-line pseudo-element</a></h4> |
| 1836 |
| 1837 <p>The <code>::first-line</code> pseudo-element describes the contents |
| 1838 of the first formatted line of an element. |
| 1839 |
| 1840 <div class="example"> |
| 1841 <p>CSS example:</p> |
| 1842 <pre>p::first-line { text-transform: uppercase }</pre> |
| 1843 <p>The above rule means "change the letters of the first line of every |
| 1844 paragraph to uppercase".</p> |
| 1845 </div> |
| 1846 |
| 1847 <p>The selector <code>p::first-line</code> does not match any real |
| 1848 HTML element. It does match a pseudo-element that conforming user |
| 1849 agents will insert at the beginning of every paragraph.</p> |
| 1850 |
| 1851 <p>Note that the length of the first line depends on a number of |
| 1852 factors, including the width of the page, the font size, etc. Thus, |
| 1853 an ordinary HTML paragraph such as:</p> |
| 1854 |
| 1855 <pre> |
| 1856 <P>This is a somewhat long HTML |
| 1857 paragraph that will be broken into several |
| 1858 lines. The first line will be identified |
| 1859 by a fictional tag sequence. The other lines |
| 1860 will be treated as ordinary lines in the |
| 1861 paragraph.</P> |
| 1862 </pre> |
| 1863 |
| 1864 <p>the lines of which happen to be broken as follows: |
| 1865 |
| 1866 <pre> |
| 1867 THIS IS A SOMEWHAT LONG HTML PARAGRAPH THAT |
| 1868 will be broken into several lines. The first |
| 1869 line will be identified by a fictional tag |
| 1870 sequence. The other lines will be treated as |
| 1871 ordinary lines in the paragraph. |
| 1872 </pre> |
| 1873 |
| 1874 <p>This paragraph might be "rewritten" by user agents to include the |
| 1875 <em>fictional tag sequence</em> for <code>::first-line</code>. This |
| 1876 fictional tag sequence helps to show how properties are inherited.</p> |
| 1877 |
| 1878 <pre> |
| 1879 <P><b><P::first-line></b> This is a somewhat long HTML |
| 1880 paragraph that <b></P::first-line></b> will be broken into several |
| 1881 lines. The first line will be identified |
| 1882 by a fictional tag sequence. The other lines |
| 1883 will be treated as ordinary lines in the |
| 1884 paragraph.</P> |
| 1885 </pre> |
| 1886 |
| 1887 <p>If a pseudo-element breaks up a real element, the desired effect |
| 1888 can often be described by a fictional tag sequence that closes and |
| 1889 then re-opens the element. Thus, if we mark up the previous paragraph |
| 1890 with a <code>span</code> element:</p> |
| 1891 |
| 1892 <pre> |
| 1893 <P><b><SPAN class="test"></b> This is a somewhat long HTML |
| 1894 paragraph that will be broken into several |
| 1895 lines.<b></SPAN></b> The first line will be identified |
| 1896 by a fictional tag sequence. The other lines |
| 1897 will be treated as ordinary lines in the |
| 1898 paragraph.</P> |
| 1899 </pre> |
| 1900 |
| 1901 <p>the user agent could simulate start and end tags for |
| 1902 <code>span</code> when inserting the fictional tag sequence for |
| 1903 <code>::first-line</code>. |
| 1904 |
| 1905 <pre> |
| 1906 <P><P::first-line><b><SPAN class="test"></b> This is a |
| 1907 somewhat long HTML |
| 1908 paragraph that will <b></SPAN></b></P::first-line><b><SPAN class=
"test"></b> be |
| 1909 broken into several |
| 1910 lines.<b></SPAN></b> The first line will be identified |
| 1911 by a fictional tag sequence. The other lines |
| 1912 will be treated as ordinary lines in the |
| 1913 paragraph.</P> |
| 1914 </pre> |
| 1915 |
| 1916 <p>In CSS, the <code>::first-line</code> pseudo-element can only be |
| 1917 attached to a block-level element, an inline-block, a table-caption, |
| 1918 or a table-cell.</p> |
| 1919 |
| 1920 <p><a name="first-formatted-line"></a>The "first formatted line" of an |
| 1921 element may occur inside a |
| 1922 block-level descendant in the same flow (i.e., a block-level |
| 1923 descendant that is not positioned and not a float). E.g., the first |
| 1924 line of the <code>div</code> in <code><DIV><P>This |
| 1925 line...</P></DIV></code> is the first line of the <code>p</code> (assuming |
| 1926 that both <code>p</code> and <code>div</code> are block-level). |
| 1927 |
| 1928 <p>The first line of a table-cell or inline-block cannot be the first |
| 1929 formatted line of an ancestor element. Thus, in <code><DIV><P |
| 1930 STYLE="display: inline-block">Hello<BR>Goodbye</P> |
| 1931 etcetera</DIV></code> the first formatted line of the |
| 1932 <code>div</code> is not the line "Hello". |
| 1933 |
| 1934 <p class="note">Note that the first line of the <code>p</code> in this |
| 1935 fragment: <code><p><br>First...</code> doesn't contain any |
| 1936 letters (assuming the default style for <code>br</code> in HTML |
| 1937 4). The word "First" is not on the first formatted line. |
| 1938 |
| 1939 <p>A UA should act as if the fictional start tags of the |
| 1940 <code>::first-line</code> pseudo-elements were nested just inside the |
| 1941 innermost enclosing block-level element. (Since CSS1 and CSS2 were |
| 1942 silent on this case, authors should not rely on this behavior.) Here |
| 1943 is an example. The fictional tag sequence for</p> |
| 1944 |
| 1945 <pre> |
| 1946 <DIV> |
| 1947 <P>First paragraph</P> |
| 1948 <P>Second paragraph</P> |
| 1949 </DIV> |
| 1950 </pre> |
| 1951 |
| 1952 <p>is</p> |
| 1953 |
| 1954 <pre> |
| 1955 <DIV> |
| 1956 <P><DIV::first-line><P::first-line>First paragraph</P::first-line>
</DIV::first-line></P> |
| 1957 <P><P::first-line>Second paragraph</P::first-line></P> |
| 1958 </DIV> |
| 1959 </pre> |
| 1960 |
| 1961 <p>The <code>::first-line</code> pseudo-element is similar to an |
| 1962 inline-level element, but with certain restrictions. In CSS, the |
| 1963 following properties apply to a <code>::first-line</code> |
| 1964 pseudo-element: font properties, color property, background |
| 1965 properties, 'word-spacing', 'letter-spacing', 'text-decoration', |
| 1966 'vertical-align', 'text-transform', 'line-height'. UAs may apply other |
| 1967 properties as well.</p> |
| 1968 |
| 1969 |
| 1970 <h4><a name=first-letter>7.2. The ::first-letter pseudo-element</a></h4> |
| 1971 |
| 1972 <p>The <code>::first-letter</code> pseudo-element represents the first |
| 1973 letter of the first line of a block, if it is not preceded by any |
| 1974 other content (such as images or inline tables) on its line. The |
| 1975 ::first-letter pseudo-element may be used for "initial caps" and "drop |
| 1976 caps", which are common typographical effects. This type of initial |
| 1977 letter is similar to an inline-level element if its 'float' property |
| 1978 is 'none'; otherwise, it is similar to a floated element.</p> |
| 1979 |
| 1980 <p>In CSS, these are the properties that apply to <code>::first-letter</code> |
| 1981 pseudo-elements: font properties, 'text-decoration', 'text-transform', |
| 1982 'letter-spacing', 'word-spacing' (when appropriate), 'line-height', |
| 1983 'float', 'vertical-align' (only if 'float' is 'none'), margin |
| 1984 properties, padding properties, border properties, color property, |
| 1985 background properties. UAs may apply other properties as well. To |
| 1986 allow UAs to render a typographically correct drop cap or initial cap, |
| 1987 the UA may choose a line-height, width and height based on the shape |
| 1988 of the letter, unlike for normal elements.</p> |
| 1989 |
| 1990 <div class="example"> |
| 1991 <p>Example:</p> |
| 1992 <p>This example shows a possible rendering of an initial cap. Note |
| 1993 that the 'line-height' that is inherited by the <code>::first-letter</code> |
| 1994 pseudo-element is 1.1, but the UA in this example has computed the |
| 1995 height of the first letter differently, so that it doesn't cause any |
| 1996 unnecessary space between the first two lines. Also note that the |
| 1997 fictional start tag of the first letter is inside the <span>span</span>, and thu
s |
| 1998 the font weight of the first letter is normal, not bold as the <span>span</span>
: |
| 1999 <pre> |
| 2000 p { line-height: 1.1 } |
| 2001 p::first-letter { font-size: 3em; font-weight: normal } |
| 2002 span { font-weight: bold } |
| 2003 ... |
| 2004 <p><span>Het hemelsche</span> gerecht heeft zich ten lange lesten<br
> |
| 2005 Erbarremt over my en mijn benaeuwde vesten<br> |
| 2006 En arme burgery, en op mijn volcx gebed<br> |
| 2007 En dagelix geschrey de bange stad ontzet. |
| 2008 </pre> |
| 2009 <div class="figure"> |
| 2010 <p><img src="initial-cap.png" alt="Image illustrating the ::first-letter pseudo-
element"> |
| 2011 </div> |
| 2012 </div> |
| 2013 |
| 2014 <div class="example"> |
| 2015 <p>The following CSS will make a drop cap initial letter span about two lines:</
p> |
| 2016 |
| 2017 <pre> |
| 2018 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"> |
| 2019 <HTML> |
| 2020 <HEAD> |
| 2021 <TITLE>Drop cap initial letter</TITLE> |
| 2022 <STYLE type="text/css"> |
| 2023 P { font-size: 12pt; line-height: 1.2 } |
| 2024 P::first-letter { font-size: 200%; font-weight: bold; float: left } |
| 2025 SPAN { text-transform: uppercase } |
| 2026 </STYLE> |
| 2027 </HEAD> |
| 2028 <BODY> |
| 2029 <P><SPAN>The first</SPAN> few words of an article |
| 2030 in The Economist.</P> |
| 2031 </BODY> |
| 2032 </HTML> |
| 2033 </pre> |
| 2034 |
| 2035 <p>This example might be formatted as follows:</p> |
| 2036 |
| 2037 <div class="figure"> |
| 2038 <P><img src="first-letter.gif" alt="Image illustrating the combined effect of th
e ::first-letter and ::first-line pseudo-elements"></p> |
| 2039 </div> |
| 2040 |
| 2041 <p>The <span class="index-inst" title="fictional tag |
| 2042 sequence">fictional tag sequence</span> is:</p> |
| 2043 |
| 2044 <pre> |
| 2045 <P> |
| 2046 <SPAN> |
| 2047 <P::first-letter> |
| 2048 T |
| 2049 </P::first-letter>he first |
| 2050 </SPAN> |
| 2051 few words of an article in the Economist. |
| 2052 </P> |
| 2053 </pre> |
| 2054 |
| 2055 <p>Note that the <code>::first-letter</code> pseudo-element tags abut |
| 2056 the content (i.e., the initial character), while the ::first-line |
| 2057 pseudo-element start tag is inserted right after the start tag of the |
| 2058 block element.</p> </div> |
| 2059 |
| 2060 <p>In order to achieve traditional drop caps formatting, user agents |
| 2061 may approximate font sizes, for example to align baselines. Also, the |
| 2062 glyph outline may be taken into account when formatting.</p> |
| 2063 |
| 2064 <p>Punctuation (i.e, characters defined in Unicode in the "open" (Ps), |
| 2065 "close" (Pe), "initial" (Pi). "final" (Pf) and "other" (Po) |
| 2066 punctuation classes), that precedes or follows the first letter should |
| 2067 be included. <a href="#refsUNICODE">[UNICODE]</a></p> |
| 2068 |
| 2069 <div class="figure"> |
| 2070 <P><img src="first-letter2.gif" alt="Quotes that precede the |
| 2071 first letter should be included."></p> |
| 2072 </div> |
| 2073 |
| 2074 <p>The <code>::first-letter</code> also applies if the first letter is |
| 2075 in fact a digit, e.g., the "6" in "67 million dollars is a lot of |
| 2076 money."</p> |
| 2077 |
| 2078 <p>In CSS, the <code>::first-letter</code> pseudo-element applies to |
| 2079 block, list-item, table-cell, table-caption, and inline-block |
| 2080 elements. <span class="note">A future version of this specification |
| 2081 may allow this pesudo-element to apply to more element |
| 2082 types.</span></p> |
| 2083 |
| 2084 <p>The <code>::first-letter</code> pseudo-element can be used with all |
| 2085 such elements that contain text, or that have a descendant in the same |
| 2086 flow that contains text. A UA should act as if the fictional start tag |
| 2087 of the ::first-letter pseudo-element is just before the first text of |
| 2088 the element, even if that first text is in a descendant.</p> |
| 2089 |
| 2090 <div class="example"> |
| 2091 <p>Example:</p> |
| 2092 <p>The fictional tag sequence for this HTMLfragment: |
| 2093 <pre><div> |
| 2094 <p>The first text.</pre> |
| 2095 <p>is: |
| 2096 <pre><div> |
| 2097 <p><div::first-letter><p::first-letter>T</...></...>he first text
.</pre> |
| 2098 </div> |
| 2099 |
| 2100 <p>The first letter of a table-cell or inline-block cannot be the |
| 2101 first letter of an ancestor element. Thus, in <code><DIV><P |
| 2102 STYLE="display: inline-block">Hello<BR>Goodbye</P> |
| 2103 etcetera</DIV></code> the first letter of the <code>div</code> is not the |
| 2104 letter "H". In fact, the <code>div</code> doesn't have a first letter. |
| 2105 |
| 2106 <p>The first letter must occur on the <a |
| 2107 href="#first-formatted-line">first formatted line.</a> For example, in |
| 2108 this fragment: <code><p><br>First...</code> the first line |
| 2109 doesn't contain any letters and <code>::first-letter</code> doesn't |
| 2110 match anything (assuming the default style for <code>br</code> in HTML |
| 2111 4). In particular, it does not match the "F" of "First." |
| 2112 |
| 2113 <p>In CSS, if an element is a list item ('display: list-item'), the |
| 2114 <code>::first-letter</code> applies to the first letter in the |
| 2115 principal box after the marker. UAs may ignore |
| 2116 <code>::first-letter</code> on list items with 'list-style-position: |
| 2117 inside'. If an element has <code>::before</code> or |
| 2118 <code>::after</code> content, the <code>::first-letter</code> applies |
| 2119 to the first letter of the element <em>including</em> that content. |
| 2120 |
| 2121 <div class="example"> |
| 2122 <p>Example:</p> |
| 2123 <p>After the rule 'p::before {content: "Note: "}', the selector |
| 2124 'p::first-letter' matches the "N" of "Note".</p> |
| 2125 </div> |
| 2126 |
| 2127 <p>Some languages may have specific rules about how to treat certain |
| 2128 letter combinations. In Dutch, for example, if the letter combination |
| 2129 "ij" appears at the beginning of a word, both letters should be |
| 2130 considered within the <code>::first-letter</code> pseudo-element. |
| 2131 |
| 2132 <p>If the letters that would form the ::first-letter are not in the |
| 2133 same element, such as "'T" in <code><p>'<em>T...</code>, the UA |
| 2134 may create a ::first-letter pseudo-element from one of the elements, |
| 2135 both elements, or simply not create a pseudo-element.</p> |
| 2136 |
| 2137 <p>Similarly, if the first letter(s) of the block are not at the start |
| 2138 of the line (for example due to bidirectional reordering), then the UA |
| 2139 need not create the pseudo-element(s). |
| 2140 |
| 2141 <div class="example"> |
| 2142 <p>Example:</p> |
| 2143 <p><a name="overlapping-example">The following example</a> illustrates |
| 2144 how overlapping pseudo-elements may interact. The first letter of |
| 2145 each P element will be green with a font size of '24pt'. The rest of |
| 2146 the first formatted line will be 'blue' while the rest of the |
| 2147 paragraph will be 'red'.</p> |
| 2148 |
| 2149 <pre>p { color: red; font-size: 12pt } |
| 2150 p::first-letter { color: green; font-size: 200% } |
| 2151 p::first-line { color: blue } |
| 2152 |
| 2153 <P>Some text that ends up on two lines</P></pre> |
| 2154 |
| 2155 <p>Assuming that a line break will occur before the word "ends", the |
| 2156 <span class="index-inst" title="fictional tag sequence">fictional tag |
| 2157 sequence</span> for this fragment might be:</p> |
| 2158 |
| 2159 <pre><P> |
| 2160 <P::first-line> |
| 2161 <P::first-letter> |
| 2162 S |
| 2163 </P::first-letter>ome text that |
| 2164 </P::first-line> |
| 2165 ends up on two lines |
| 2166 </P></pre> |
| 2167 |
| 2168 <p>Note that the <code>::first-letter</code> element is inside the <code>::first
-line</code> |
| 2169 element. Properties set on <code>::first-line</code> are inherited by |
| 2170 <code>::first-letter</code>, but are overridden if the same property is set on |
| 2171 <code>::first-letter</code>.</p> |
| 2172 </div> |
| 2173 |
| 2174 |
| 2175 <h4><a name=UIfragments>7.3.</a> <a name=selection>The ::selection pseudo-elemen
t</a></h4> |
| 2176 |
| 2177 <p>The <code>::selection</code> pseudo-element applies to the portion |
| 2178 of a document that has been highlighted by the user. This also |
| 2179 applies, for example, to selected text within an editable text |
| 2180 field. This pseudo-element should not be confused with the <code><a |
| 2181 href="#checked">:checked</a></code> pseudo-class (which used to be |
| 2182 named <code>:selected</code>) |
| 2183 |
| 2184 <p>Although the <code>::selection</code> pseudo-element is dynamic in |
| 2185 nature, and is altered by user action, it is reasonable to expect that |
| 2186 when a UA re-renders to a static medium (such as a printed page, see |
| 2187 <a href="#refsCSS21">[CSS21]</a>) which was originally rendered to a |
| 2188 dynamic medium (like screen), the UA may wish to transfer the current |
| 2189 <code>::selection</code> state to that other medium, and have all the |
| 2190 appropriate formatting and rendering take effect as well. This is not |
| 2191 required — UAs may omit the <code>::selection</code> |
| 2192 pseudo-element for static media. |
| 2193 |
| 2194 <p>These are the CSS properties that apply to <code>::selection</code> |
| 2195 pseudo-elements: color, background, cursor (optional), outline |
| 2196 (optional). The computed value of the 'background-image' property on |
| 2197 <code>::selection</code> may be ignored. |
| 2198 |
| 2199 |
| 2200 <h4><a name=gen-content>7.4. The ::before and ::after pseudo-elements</a></h4> |
| 2201 |
| 2202 <p>The <code>::before</code> and <code>::after</code> pseudo-elements |
| 2203 can be used to describe generated content before or after an element's |
| 2204 content. They are explained in CSS 2.1 <a |
| 2205 href="#refsCSS21">[CSS21]</a>.</p> |
| 2206 |
| 2207 <p>When the <code>::first-letter</code> and <code>::first-line</code> |
| 2208 pseudo-elements are combined with <code>::before</code> and |
| 2209 <code>::after</code>, they apply to the first letter or line of the |
| 2210 element including the inserted text.</p> |
| 2211 |
| 2212 <h2><a name=combinators>8. Combinators</a></h2> |
| 2213 |
| 2214 <h3><a name=descendant-combinators>8.1. Descendant combinator</a></h3> |
| 2215 |
| 2216 <p>At times, authors may want selectors to describe an element that is |
| 2217 the descendant of another element in the document tree (e.g., "an |
| 2218 <code>EM</code> element that is contained within an <code>H1</code> |
| 2219 element"). Descendant combinators express such a relationship. A |
| 2220 descendant combinator is <a href="#whitespace">white space</a> that |
| 2221 separates two sequences of simple selectors. A selector of the form |
| 2222 "<code>A B</code>" represents an element <code>B</code> that is an |
| 2223 arbitrary descendant of some ancestor element <code>A</code>. |
| 2224 |
| 2225 <div class="example"> |
| 2226 <p>Examples:</p> |
| 2227 <p>For example, consider the following selector:</p> |
| 2228 <pre>h1 em</pre> |
| 2229 <p>It represents an <code>em</code> element being the descendant of |
| 2230 an <code>h1</code> element. It is a correct and valid, but partial, |
| 2231 description of the following fragment:</p> |
| 2232 <pre><h1>This <span class="myclass">headline |
| 2233 is <em>very</em> important</span></h1></pre> |
| 2234 <p>The following selector:</p> |
| 2235 <pre>div * p</pre> |
| 2236 <p>represents a <code>p</code> element that is a grandchild or later |
| 2237 descendant of a <code>div</code> element. Note the whitespace on |
| 2238 either side of the "*" is not part of the universal selector; the |
| 2239 whitespace is a combinator indicating that the DIV must be the |
| 2240 ancestor of some element, and that that element must be an ancestor |
| 2241 of the P.</p> |
| 2242 <p>The following selector, which combines descendant combinators and |
| 2243 <a href="#attribute-selectors">attribute selectors</a>, represents an |
| 2244 element that (1) has the <code>href</code> attribute set and (2) is |
| 2245 inside a <code>p</code> that is itself inside a <code>div</code>:</p> |
| 2246 <pre>div p *[href]</pre> |
| 2247 </div> |
| 2248 |
| 2249 <h3><a name=child-combinators>8.2. Child combinators</a></h3> |
| 2250 |
| 2251 <p>A <dfn>child combinator</dfn> describes a childhood relationship |
| 2252 between two elements. A child combinator is made of the |
| 2253 "greater-than sign" (<code>></code>) character and |
| 2254 separates two sequences of simple selectors. |
| 2255 |
| 2256 |
| 2257 <div class="example"> |
| 2258 <p>Examples:</p> |
| 2259 <p>The following selector represents a <code>p</code> element that is |
| 2260 child of <code>body</code>:</p> |
| 2261 <pre>body > p</pre> |
| 2262 <p>The following example combines descendant combinators and child |
| 2263 combinators.</p> |
| 2264 <pre>div ol>li p</pre><!-- LEAVE THOSE SPACES OUT! see below --> |
| 2265 <p>It represents a <code>p</code> element that is a descendant of an |
| 2266 <code>li</code> element; the <code>li</code> element must be the |
| 2267 child of an <code>ol</code> element; the <code>ol</code> element must |
| 2268 be a descendant of a <code>div</code>. Notice that the optional white |
| 2269 space around the ">" combinator has been left out.</p> |
| 2270 </div> |
| 2271 |
| 2272 <p>For information on selecting the first child of an element, please |
| 2273 see the section on the <code><a |
| 2274 href="#structural-pseudos">:first-child</a></code> pseudo-class |
| 2275 above.</p> |
| 2276 |
| 2277 <h3><a name=sibling-combinators>8.3. Sibling combinators</a></h3> |
| 2278 |
| 2279 <p>There are two different sibling combinators: the adjacent sibling |
| 2280 combinator and the general sibling combinator. In both cases, |
| 2281 non-element nodes (e.g. text between elements) are ignored when |
| 2282 considering adjacency of elements.</p> |
| 2283 |
| 2284 <h4><a name=adjacent-sibling-combinators>8.3.1. Adjacent sibling combinator</a><
/h4> |
| 2285 |
| 2286 <p>The adjacent sibling combinator is made of the "plus |
| 2287 sign" (U+002B, <code>+</code>) character that separates two |
| 2288 sequences of simple selectors. The elements represented by the two |
| 2289 sequences share the same parent in the document tree and the element |
| 2290 represented by the first sequence immediately precedes the element |
| 2291 represented by the second one.</p> |
| 2292 |
| 2293 <div class="example"> |
| 2294 <p>Examples:</p> |
| 2295 <p>The following selector represents a <code>p</code> element |
| 2296 immediately following a <code>math</code> element:</p> |
| 2297 <pre>math + p</pre> |
| 2298 <p>The following selector is conceptually similar to the one in the |
| 2299 previous example, except that it adds an attribute selector — it |
| 2300 adds a constraint to the <code>h1</code> element, that it must have |
| 2301 <code>class="opener"</code>:</p> |
| 2302 <pre>h1.opener + h2</pre> |
| 2303 </div> |
| 2304 |
| 2305 |
| 2306 <h4><a name=general-sibling-combinators>8.3.2. General sibling combinator</a></h
4> |
| 2307 |
| 2308 <p>The general sibling combinator is made of the "tilde" |
| 2309 (U+007E, <code>~</code>) character that separates two sequences of |
| 2310 simple selectors. The elements represented by the two sequences share |
| 2311 the same parent in the document tree and the element represented by |
| 2312 the first sequence precedes (not necessarily immediately) the element |
| 2313 represented by the second one.</p> |
| 2314 |
| 2315 <div class="example"> |
| 2316 <p>Example:</p> |
| 2317 <pre>h1 ~ pre</pre> |
| 2318 <p>represents a <code>pre</code> element following an <code>h1</code>. It |
| 2319 is a correct and valid, but partial, description of:</p> |
| 2320 <pre><h1>Definition of the function a</h1> |
| 2321 <p>Function a(x) has to be applied to all figures in the table.</p> |
| 2322 <pre>function a(x) = 12x/13.5</pre></pre> |
| 2323 </div> |
| 2324 |
| 2325 <h2><a name=specificity>9. Calculating a selector's specificity</a></h2> |
| 2326 |
| 2327 <p>A selector's specificity is calculated as follows:</p> |
| 2328 |
| 2329 <ul> |
| 2330 <li>count the number of ID selectors in the selector (= a)</li> |
| 2331 <li>count the number of class selectors, attributes selectors, and pseudo-clas
ses in the selector (= b)</li> |
| 2332 <li>count the number of element names in the selector (= c)</li> |
| 2333 <li>ignore pseudo-elements</li> |
| 2334 </ul> |
| 2335 |
| 2336 <p>Selectors inside <a href="#negation">the negation pseudo-class</a> |
| 2337 are counted like any other, but the negation itself does not count as |
| 2338 a pseudo-class.</p> |
| 2339 |
| 2340 <p>Concatenating the three numbers a-b-c (in a number system with a |
| 2341 large base) gives the specificity.</p> |
| 2342 |
| 2343 <div class="example"> |
| 2344 <p>Examples:</p> |
| 2345 <pre>* /* a=0 b=0 c=0 -> specificity = 0 */ |
| 2346 LI /* a=0 b=0 c=1 -> specificity = 1 */ |
| 2347 UL LI /* a=0 b=0 c=2 -> specificity = 2 */ |
| 2348 UL OL+LI /* a=0 b=0 c=3 -> specificity = 3 */ |
| 2349 H1 + *[REL=up] /* a=0 b=1 c=1 -> specificity = 11 */ |
| 2350 UL OL LI.red /* a=0 b=1 c=3 -> specificity = 13 */ |
| 2351 LI.red.level /* a=0 b=2 c=1 -> specificity = 21 */ |
| 2352 #x34y /* a=1 b=0 c=0 -> specificity = 100 */ |
| 2353 #s12:not(FOO) /* a=1 b=0 c=1 -> specificity = 101 */ |
| 2354 </pre> |
| 2355 </div> |
| 2356 |
| 2357 <p class="note"><strong>Note:</strong> the specificity of the styles |
| 2358 specified in an HTML <code>style</code> attribute is described in CSS |
| 2359 2.1. <a href="#refsCSS21">[CSS21]</a>.</p> |
| 2360 |
| 2361 <h2><a name=w3cselgrammar>10. The grammar of Selectors</a></h2> |
| 2362 |
| 2363 <h3><a name=grammar>10.1. Grammar</a></h3> |
| 2364 |
| 2365 <p>The grammar below defines the syntax of Selectors. It is globally |
| 2366 LL(1) and can be locally LL(2) (but note that most UA's should not use |
| 2367 it directly, since it doesn't express the parsing conventions). The |
| 2368 format of the productions is optimized for human consumption and some |
| 2369 shorthand notations beyond Yacc (see <a href="#refsYACC">[YACC]</a>) |
| 2370 are used:</p> |
| 2371 |
| 2372 <ul> |
| 2373 <li><b>*</b>: 0 or more |
| 2374 <li><b>+</b>: 1 or more |
| 2375 <li><b>?</b>: 0 or 1 |
| 2376 <li><b>|</b>: separates alternatives |
| 2377 <li><b>[ ]</b>: grouping </li> |
| 2378 </ul> |
| 2379 |
| 2380 <p>The productions are:</p> |
| 2381 |
| 2382 <pre>selectors_group |
| 2383 : selector [ COMMA S* selector ]* |
| 2384 ; |
| 2385 |
| 2386 selector |
| 2387 : simple_selector_sequence [ combinator simple_selector_sequence ]* |
| 2388 ; |
| 2389 |
| 2390 combinator |
| 2391 /* combinators can be surrounded by white space */ |
| 2392 : PLUS S* | GREATER S* | TILDE S* | S+ |
| 2393 ; |
| 2394 |
| 2395 simple_selector_sequence |
| 2396 : [ type_selector | universal ] |
| 2397 [ HASH | class | attrib | pseudo | negation ]* |
| 2398 | [ HASH | class | attrib | pseudo | negation ]+ |
| 2399 ; |
| 2400 |
| 2401 type_selector |
| 2402 : [ namespace_prefix ]? element_name |
| 2403 ; |
| 2404 |
| 2405 namespace_prefix |
| 2406 : [ IDENT | '*' ]? '|' |
| 2407 ; |
| 2408 |
| 2409 element_name |
| 2410 : IDENT |
| 2411 ; |
| 2412 |
| 2413 universal |
| 2414 : [ namespace_prefix ]? '*' |
| 2415 ; |
| 2416 |
| 2417 class |
| 2418 : '.' IDENT |
| 2419 ; |
| 2420 |
| 2421 attrib |
| 2422 : '[' S* [ namespace_prefix ]? IDENT S* |
| 2423 [ [ PREFIXMATCH | |
| 2424 SUFFIXMATCH | |
| 2425 SUBSTRINGMATCH | |
| 2426 '=' | |
| 2427 INCLUDES | |
| 2428 DASHMATCH ] S* [ IDENT | STRING ] S* |
| 2429 ]? ']' |
| 2430 ; |
| 2431 |
| 2432 pseudo |
| 2433 /* '::' starts a pseudo-element, ':' a pseudo-class */ |
| 2434 /* Exceptions: :first-line, :first-letter, :before and :after. */ |
| 2435 /* Note that pseudo-elements are restricted to one per selector and */ |
| 2436 /* occur only in the last simple_selector_sequence. */ |
| 2437 : ':' ':'? [ IDENT | functional_pseudo ] |
| 2438 ; |
| 2439 |
| 2440 functional_pseudo |
| 2441 : FUNCTION S* expression ')' |
| 2442 ; |
| 2443 |
| 2444 expression |
| 2445 /* In CSS3, the expressions are identifiers, strings, */ |
| 2446 /* or of the form "an+b" */ |
| 2447 : [ [ PLUS | '-' | DIMENSION | NUMBER | STRING | IDENT ] S* ]+ |
| 2448 ; |
| 2449 |
| 2450 negation |
| 2451 : NOT S* negation_arg S* ')' |
| 2452 ; |
| 2453 |
| 2454 negation_arg |
| 2455 : type_selector | universal | HASH | class | attrib | pseudo |
| 2456 ;</pre> |
| 2457 |
| 2458 |
| 2459 <h3><a name=lex>10.2. Lexical scanner</a></h3> |
| 2460 |
| 2461 <p>The following is the <a name=x3>tokenizer</a>, written in Flex (see |
| 2462 <a href="#refsFLEX">[FLEX]</a>) notation. The tokenizer is |
| 2463 case-insensitive.</p> |
| 2464 |
| 2465 <p>The two occurrences of "\377" represent the highest character |
| 2466 number that current versions of Flex can deal with (decimal 255). They |
| 2467 should be read as "\4177777" (decimal 1114111), which is the highest |
| 2468 possible code point in Unicode/ISO-10646. <a |
| 2469 href="#refsUNICODE">[UNICODE]</a></p> |
| 2470 |
| 2471 <pre>%option case-insensitive |
| 2472 |
| 2473 ident [-]?{nmstart}{nmchar}* |
| 2474 name {nmchar}+ |
| 2475 nmstart [_a-z]|{nonascii}|{escape} |
| 2476 nonascii [^\0-\177] |
| 2477 unicode \\[0-9a-f]{1,6}(\r\n|[ \n\r\t\f])? |
| 2478 escape {unicode}|\\[^\n\r\f0-9a-f] |
| 2479 nmchar [_a-z0-9-]|{nonascii}|{escape} |
| 2480 num [0-9]+|[0-9]*\.[0-9]+ |
| 2481 string {string1}|{string2} |
| 2482 string1 \"([^\n\r\f\\"]|\\{nl}|{nonascii}|{escape})*\" |
| 2483 string2 \'([^\n\r\f\\']|\\{nl}|{nonascii}|{escape})*\' |
| 2484 invalid {invalid1}|{invalid2} |
| 2485 invalid1 \"([^\n\r\f\\"]|\\{nl}|{nonascii}|{escape})* |
| 2486 invalid2 \'([^\n\r\f\\']|\\{nl}|{nonascii}|{escape})* |
| 2487 nl \n|\r\n|\r|\f |
| 2488 w [ \t\r\n\f]* |
| 2489 |
| 2490 %% |
| 2491 |
| 2492 [ \t\r\n\f]+ return S; |
| 2493 |
| 2494 "~=" return INCLUDES; |
| 2495 "|=" return DASHMATCH; |
| 2496 "^=" return PREFIXMATCH; |
| 2497 "$=" return SUFFIXMATCH; |
| 2498 "*=" return SUBSTRINGMATCH; |
| 2499 {ident} return IDENT; |
| 2500 {string} return STRING; |
| 2501 {ident}"(" return FUNCTION; |
| 2502 {num} return NUMBER; |
| 2503 "#"{name} return HASH; |
| 2504 {w}"+" return PLUS; |
| 2505 {w}">" return GREATER; |
| 2506 {w}"," return COMMA; |
| 2507 {w}"~" return TILDE; |
| 2508 ":not(" return NOT; |
| 2509 @{ident} return ATKEYWORD; |
| 2510 {invalid} return INVALID; |
| 2511 {num}% return PERCENTAGE; |
| 2512 {num}{ident} return DIMENSION; |
| 2513 "<!--" return CDO; |
| 2514 "-->" return CDC; |
| 2515 |
| 2516 "url("{w}{string}{w}")" return URI; |
| 2517 "url("{w}([!#$%&*-~]|{nonascii}|{escape})*{w}")" return URI; |
| 2518 U\+[0-9a-f?]{1,6}(-[0-9a-f]{1,6})? return UNICODE_RANGE; |
| 2519 |
| 2520 \/\*[^*]*\*+([^/*][^*]*\*+)*\/ /* ignore comments */ |
| 2521 |
| 2522 . return *yytext;</pre> |
| 2523 |
| 2524 |
| 2525 |
| 2526 <h2><a name=downlevel>11. Namespaces and down-level clients</a></h2> |
| 2527 |
| 2528 <p>An important issue is the interaction of CSS selectors with XML |
| 2529 documents in web clients that were produced prior to this |
| 2530 document. Unfortunately, due to the fact that namespaces must be |
| 2531 matched based on the URI which identifies the namespace, not the |
| 2532 namespace prefix, some mechanism is required to identify namespaces in |
| 2533 CSS by their URI as well. Without such a mechanism, it is impossible |
| 2534 to construct a CSS style sheet which will properly match selectors in |
| 2535 all cases against a random set of XML documents. However, given |
| 2536 complete knowledge of the XML document to which a style sheet is to be |
| 2537 applied, and a limited use of namespaces within the XML document, it |
| 2538 is possible to construct a style sheet in which selectors would match |
| 2539 elements and attributes correctly.</p> |
| 2540 |
| 2541 <p>It should be noted that a down-level CSS client will (if it |
| 2542 properly conforms to CSS forward compatible parsing rules) ignore all |
| 2543 <code>@namespace</code> at-rules, as well as all style rules that make |
| 2544 use of namespace qualified element type or attribute selectors. The |
| 2545 syntax of delimiting namespace prefixes in CSS was deliberately chosen |
| 2546 so that down-level CSS clients would ignore the style rules rather |
| 2547 than possibly match them incorrectly.</p> |
| 2548 |
| 2549 <p>The use of default namespaces in CSS makes it possible to write |
| 2550 element type selectors that will function in both namespace aware CSS |
| 2551 clients as well as down-level clients. It should be noted that |
| 2552 down-level clients may incorrectly match selectors against XML |
| 2553 elements in other namespaces.</p> |
| 2554 |
| 2555 <p>The following are scenarios and examples in which it is possible to |
| 2556 construct style sheets which would function properly in web clients |
| 2557 that do not implement this proposal.</p> |
| 2558 |
| 2559 <ol> |
| 2560 <li> |
| 2561 |
| 2562 <p>The XML document does not use namespaces.</p> |
| 2563 |
| 2564 <ul> |
| 2565 |
| 2566 <li>In this case, it is obviously not necessary to declare or use |
| 2567 namespaces in the style sheet. Standard CSS element type and |
| 2568 attribute selectors will function adequately in a down-level |
| 2569 client.</li> |
| 2570 |
| 2571 <li>In a CSS namespace aware client, the default behavior of |
| 2572 element selectors matching without regard to namespace will |
| 2573 function properly against all elements, since no namespaces are |
| 2574 present. However, the use of specific element type selectors that |
| 2575 match only elements that have no namespace ("<code>|name</code>") |
| 2576 will guarantee that selectors will match only XML elements that do |
| 2577 not have a declared namespace. </li> |
| 2578 |
| 2579 </ul> |
| 2580 |
| 2581 </li> |
| 2582 |
| 2583 <li> |
| 2584 |
| 2585 <p>The XML document defines a single, default namespace used |
| 2586 throughout the document. No namespace prefixes are used in element |
| 2587 names.</p> |
| 2588 |
| 2589 <ul> |
| 2590 |
| 2591 <li>In this case, a down-level client will function as if |
| 2592 namespaces were not used in the XML document at all. Standard CSS |
| 2593 element type and attribute selectors will match against all |
| 2594 elements. </li> |
| 2595 |
| 2596 </ul> |
| 2597 |
| 2598 </li> |
| 2599 |
| 2600 <li> |
| 2601 |
| 2602 <p>The XML document does <b>not</b> use a default namespace, all |
| 2603 namespace prefixes used are known to the style sheet author, and |
| 2604 there is a direct mapping between namespace prefixes and namespace |
| 2605 URIs. (A given prefix may only be mapped to one namespace URI |
| 2606 throughout the XML document; there may be multiple prefixes mapped |
| 2607 to the same URI).</p> |
| 2608 |
| 2609 <ul> |
| 2610 |
| 2611 <li>In this case, the down-level client will view and match |
| 2612 element type and attribute selectors based on their fully |
| 2613 qualified name, not the local part as outlined in the <a |
| 2614 href="#typenmsp">Type selectors and Namespaces</a> section. CSS |
| 2615 selectors may be declared using an escaped colon "<code>\:</code>" |
| 2616 to describe the fully qualified names, e.g. |
| 2617 "<code>html\:h1</code>" will match |
| 2618 <code><html:h1></code>. Selectors using the qualified name |
| 2619 will only match XML elements that use the same prefix. Other |
| 2620 namespace prefixes used in the XML that are mapped to the same URI |
| 2621 will not match as expected unless additional CSS style rules are |
| 2622 declared for them.</li> |
| 2623 |
| 2624 <li>Note that selectors declared in this fashion will |
| 2625 <em>only</em> match in down-level clients. A CSS namespace aware |
| 2626 client will match element type and attribute selectors based on |
| 2627 the name's local part. Selectors declared with the fully |
| 2628 qualified name will not match (unless there is no namespace prefix |
| 2629 in the fully qualified name).</li> |
| 2630 |
| 2631 </ul> |
| 2632 |
| 2633 </li> |
| 2634 |
| 2635 </ol> |
| 2636 |
| 2637 <p>In other scenarios: when the namespace prefixes used in the XML are |
| 2638 not known in advance by the style sheet author; or a combination of |
| 2639 elements with no namespace are used in conjunction with elements using |
| 2640 a default namespace; or the same namespace prefix is mapped to |
| 2641 <em>different</em> namespace URIs within the same document, or in |
| 2642 different documents; it is impossible to construct a CSS style sheet |
| 2643 that will function properly against all elements in those documents, |
| 2644 unless, the style sheet is written using a namespace URI syntax (as |
| 2645 outlined in this document or similar) and the document is processed by |
| 2646 a CSS and XML namespace aware client.</p> |
| 2647 |
| 2648 <h2><a name=profiling>12. Profiles</a></h2> |
| 2649 |
| 2650 <p>Each specification using Selectors must define the subset of W3C |
| 2651 Selectors it allows and excludes, and describe the local meaning of |
| 2652 all the components of that subset.</p> |
| 2653 |
| 2654 <p>Non normative examples: |
| 2655 |
| 2656 <div class="profile"> |
| 2657 <table class="tprofile"> |
| 2658 <tbody> |
| 2659 <tr> |
| 2660 <th class="title" colspan=2>Selectors profile</th></tr> |
| 2661 <tr> |
| 2662 <th>Specification</th> |
| 2663 <td>CSS level 1</td></tr> |
| 2664 <tr> |
| 2665 <th>Accepts</th> |
| 2666 <td>type selectors<br>class selectors<br>ID selectors<br>:link, |
| 2667 :visited and :active pseudo-classes<br>descendant combinator |
| 2668 <br>::first-line and ::first-letter pseudo-elements</td></tr> |
| 2669 <tr> |
| 2670 <th>Excludes</th> |
| 2671 <td> |
| 2672 |
| 2673 <p>universal selector<br>attribute selectors<br>:hover and :focus |
| 2674 pseudo-classes<br>:target pseudo-class<br>:lang() pseudo-class<br>all UI |
| 2675 element states pseudo-classes<br>all structural |
| 2676 pseudo-classes<br>negation pseudo-class<br>all |
| 2677 UI element fragments pseudo-elements<br>::before and ::after |
| 2678 pseudo-elements<br>child combinators<br>sibling combinators |
| 2679 |
| 2680 <p>namespaces</td></tr> |
| 2681 <tr> |
| 2682 <th>Extra constraints</th> |
| 2683 <td>only one class selector allowed per sequence of simple |
| 2684 selectors</td></tr></tbody></table><br><br> |
| 2685 <table class="tprofile"> |
| 2686 <tbody> |
| 2687 <tr> |
| 2688 <th class="title" colspan=2>Selectors profile</th></tr> |
| 2689 <tr> |
| 2690 <th>Specification</th> |
| 2691 <td>CSS level 2</td></tr> |
| 2692 <tr> |
| 2693 <th>Accepts</th> |
| 2694 <td>type selectors<br>universal selector<br>attribute presence and |
| 2695 values selectors<br>class selectors<br>ID selectors<br>:link, :visited, |
| 2696 :active, :hover, :focus, :lang() and :first-child pseudo-classes |
| 2697 <br>descendant combinator<br>child combinator<br>adjacent sibling |
| 2698 combinator<br>::first-line and ::first-letter pseudo-elements<br>::before |
| 2699 and ::after pseudo-elements</td></tr> |
| 2700 <tr> |
| 2701 <th>Excludes</th> |
| 2702 <td> |
| 2703 |
| 2704 <p>content selectors<br>substring matching attribute |
| 2705 selectors<br>:target pseudo-classes<br>all UI element |
| 2706 states pseudo-classes<br>all structural pseudo-classes other |
| 2707 than :first-child<br>negation pseudo-class<br>all UI element |
| 2708 fragments pseudo-elements<br>general sibling combinators |
| 2709 |
| 2710 <p>namespaces</td></tr> |
| 2711 <tr> |
| 2712 <th>Extra constraints</th> |
| 2713 <td>more than one class selector per sequence of simple selectors (CSS1 |
| 2714 constraint) allowed</td></tr></tbody></table> |
| 2715 |
| 2716 <p>In CSS, selectors express pattern matching rules that determine which style |
| 2717 rules apply to elements in the document tree. |
| 2718 |
| 2719 <p>The following selector (CSS level 2) will <b>match</b> all anchors <code>a</c
ode> |
| 2720 with attribute <code>name</code> set inside a section 1 header <code>h1</code>: |
| 2721 <pre>h1 a[name]</pre> |
| 2722 |
| 2723 <p>All CSS declarations attached to such a selector are applied to elements |
| 2724 matching it. </div> |
| 2725 |
| 2726 <div class="profile"> |
| 2727 <table class="tprofile"> |
| 2728 <tbody> |
| 2729 <tr> |
| 2730 <th class="title" colspan=2>Selectors profile</th></tr> |
| 2731 <tr> |
| 2732 <th>Specification</th> |
| 2733 <td>STTS 3</td> |
| 2734 </tr> |
| 2735 <tr> |
| 2736 <th>Accepts</th> |
| 2737 <td> |
| 2738 |
| 2739 <p>type selectors<br>universal selectors<br>attribute selectors<br>class |
| 2740 selectors<br>ID selectors<br>all structural pseudo-classes<br> |
| 2741 all combinators |
| 2742 |
| 2743 <p>namespaces</td></tr> |
| 2744 <tr> |
| 2745 <th>Excludes</th> |
| 2746 <td>non-accepted pseudo-classes<br>pseudo-elements<br></td></tr> |
| 2747 <tr> |
| 2748 <th>Extra constraints</th> |
| 2749 <td>some selectors and combinators are not allowed in fragment |
| 2750 descriptions on the right side of STTS declarations.</td></tr></tbody></ta
ble> |
| 2751 <form> |
| 2752 <input type="text" name="test10"/> |
| 2753 <input type="text" name="foo"/> |
| 2754 <input type="text" name="foo"/> |
| 2755 <input type="text" name="foo"/> |
| 2756 <input type="text" name="foo"/> |
| 2757 <input type="text" name="foo"/> |
| 2758 <input type="text" name="foo"/> |
| 2759 <input type="text" name="foo"/> |
| 2760 <input type="text" name="foo"/> |
| 2761 <input type="text" name="foo"/> |
| 2762 <input type="text" name="foo"/> |
| 2763 <input type="text" name="foo"/> |
| 2764 <input type="text" name="foo"/> |
| 2765 <input type="text" name="foo"/> |
| 2766 <input type="text" name="foo"/> |
| 2767 <input type="text" name="foo"/> |
| 2768 <input type="text" name="foo"/> |
| 2769 <input type="text" name="foo"/> |
| 2770 <input type="text" name="foo"/> |
| 2771 <input type="text" name="foo"/> |
| 2772 <input type="text" name="foo"/> |
| 2773 <input type="text" name="foo"/> |
| 2774 <input type="text" name="foo"/> |
| 2775 <input type="text" name="foo"/> |
| 2776 <input type="text" name="foo"/> |
| 2777 </form> |
| 2778 |
| 2779 <p>Selectors can be used in STTS 3 in two different |
| 2780 manners: |
| 2781 <ol> |
| 2782 <li>a selection mechanism equivalent to CSS selection mechanism: declarations |
| 2783 attached to a given selector are applied to elements matching that selector, |
| 2784 <li>fragment descriptions that appear on the right side of declarations. |
| 2785 </li></ol></div> |
| 2786 |
| 2787 <h2><a name=Conformance></a>13. Conformance and requirements</h2> |
| 2788 |
| 2789 <p>This section defines conformance with the present specification only. |
| 2790 |
| 2791 <p>The inability of a user agent to implement part of this specification due to |
| 2792 the limitations of a particular device (e.g., non interactive user agents will |
| 2793 probably not implement dynamic pseudo-classes because they make no sense without |
| 2794 interactivity) does not imply non-conformance. |
| 2795 |
| 2796 <p>All specifications reusing Selectors must contain a <a |
| 2797 href="#profiling">Profile</a> listing the |
| 2798 subset of Selectors it accepts or excludes, and describing the constraints |
| 2799 it adds to the current specification. |
| 2800 |
| 2801 <p>Invalidity is caused by a parsing error, e.g. an unrecognized token or a toke
n |
| 2802 which is not allowed at the current parsing point. |
| 2803 |
| 2804 <p>User agents must observe the rules for handling parsing errors: |
| 2805 <ul> |
| 2806 <li>a simple selector containing an undeclared namespace prefix is invalid</li
> |
| 2807 <li>a selector containing an invalid simple selector, an invalid combinator |
| 2808 or an invalid token is invalid. </li> |
| 2809 <li>a group of selectors containing an invalid selector is invalid.</li> |
| 2810 </ul> |
| 2811 |
| 2812 <p class="foo test10 bar">Specifications reusing Selectors must define how to ha
ndle parsing |
| 2813 errors. (In the case of CSS, the entire rule in which the selector is |
| 2814 used is dropped.)</p> |
| 2815 |
| 2816 <!-- Apparently all these references are out of date: |
| 2817 <p>Implementations of this specification must behave as |
| 2818 "recipients of text data" as defined by <a href="#refsCWWW">[CWWW]</a> |
| 2819 when parsing selectors and attempting matches. (In particular, |
| 2820 implementations must assume the data is normalized and must not |
| 2821 normalize it.) Normative rules for matching strings are defined in |
| 2822 <a href="#refsCWWW">[CWWW]</a> and <a |
| 2823 href="#refsUNICODE">[UNICODE]</a> and apply to implementations of this |
| 2824 specification.</p>--> |
| 2825 |
| 2826 <h2><a name=Tests></a>14. Tests</h2> |
| 2827 |
| 2828 <p>This specification has <a |
| 2829 href="http://www.w3.org/Style/CSS/Test/CSS3/Selectors/current/">a test |
| 2830 suite</a> allowing user agents to verify their basic conformance to |
| 2831 the specification. This test suite does not pretend to be exhaustive |
| 2832 and does not cover all possible combined cases of Selectors.</p> |
| 2833 |
| 2834 <h2><a name=ACKS></a>15. Acknowledgements</h2> |
| 2835 |
| 2836 <p>The CSS working group would like to thank everyone who has sent |
| 2837 comments on this specification over the years.</p> |
| 2838 |
| 2839 <p>The working group would like to extend special thanks to Donna |
| 2840 McManus, Justin Baker, Joel Sklar, and Molly Ives Brower who perfermed |
| 2841 the final editorial review.</p> |
| 2842 |
| 2843 <h2><a name=references>16. References</a></h2> |
| 2844 |
| 2845 <dl class="refs"> |
| 2846 |
| 2847 <dt>[CSS1] |
| 2848 <dd><a name=refsCSS1></a> Bert Bos, Håkon Wium Lie; "<cite>Cascading Sty
le Sheets, level 1</cite>", W3C Recommendation, 17 Dec 1996, revised 11 Jan 1999 |
| 2849 <dd>(<code><a href="http://www.w3.org/TR/REC-CSS1">http://www.w3.org/TR/REC-CS
S1</a></code>) |
| 2850 |
| 2851 <dt>[CSS21] |
| 2852 <dd><a name=refsCSS21></a> Bert Bos, Tantek Çelik, Ian Hickson, Hå
;kon Wium Lie, editors; "<cite>Cascading Style Sheets, level 2 revision 1</cite>
", W3C Working Draft, 13 June 2005 |
| 2853 <dd>(<code><a href="http://www.w3.org/TR/CSS21">http://www.w3.org/TR/CSS21</a>
</code>) |
| 2854 |
| 2855 <dt>[CWWW] |
| 2856 <dd><a name=refsCWWW></a> Martin J. Dürst, François Yergeau, Misha
Wolf, Asmus Freytag, Tex Texin, editors; "<cite>Character Model for the World W
ide Web</cite>", W3C Recommendation, 15 February 2005 |
| 2857 <dd>(<code><a href="http://www.w3.org/TR/charmod/">http://www.w3.org/TR/charmo
d/</a></code>) |
| 2858 |
| 2859 <dt>[FLEX] |
| 2860 <dd><a name="refsFLEX"></a> "<cite>Flex: The Lexical Scanner Generator</cite>"
, Version 2.3.7, ISBN 1882114213 |
| 2861 |
| 2862 <dt>[HTML4] |
| 2863 <dd><a name="refsHTML4"></a> Dave Ragget, Arnaud Le Hors, Ian Jacobs, editors;
"<cite>HTML 4.01 Specification</cite>", W3C Recommendation, 24 December 1999 |
| 2864 <dd>(<a href="http://www.w3.org/TR/html4/"><code>http://www.w3.org/TR/html4/</
code></a>) |
| 2865 |
| 2866 <dt>[MATH] |
| 2867 <dd><a name="refsMATH"></a> Patrick Ion, Robert Miner, editors; "<cite>Mathema
tical Markup Language (MathML) 1.01</cite>", W3C Recommendation, revision of 7 J
uly 1999 |
| 2868 <dd>(<code><a href="http://www.w3.org/TR/REC-MathML/">http://www.w3.org/TR/REC
-MathML/</a></code>) |
| 2869 |
| 2870 <dt>[RFC3066] |
| 2871 <dd><a name="refsRFC3066"></a> H. Alvestrand; "<cite>Tags for the Identificati
on of Languages</cite>", Request for Comments 3066, January 2001 |
| 2872 <dd>(<a href="http://www.ietf.org/rfc/rfc3066.txt"><code>http://www.ietf.org/r
fc/rfc3066.txt</code></a>) |
| 2873 |
| 2874 <dt>[STTS] |
| 2875 <dd><a name=refsSTTS></a> Daniel Glazman; "<cite>Simple Tree Transformation Sh
eets 3</cite>", Electricité de France, submission to the W3C, 11 November
1998 |
| 2876 <dd>(<code><a href="http://www.w3.org/TR/NOTE-STTS3">http://www.w3.org/TR/NOTE
-STTS3</a></code>) |
| 2877 |
| 2878 <dt>[SVG] |
| 2879 <dd><a name="refsSVG"></a> Jon Ferraiolo, 藤沢 淳, Dean Jack
son, editors; "<cite>Scalable Vector Graphics (SVG) 1.1 Specification</cite>", W
3C Recommendation, 14 January 2003 |
| 2880 <dd>(<code><a href="http://www.w3.org/TR/SVG/">http://www.w3.org/TR/SVG/</a></
code>) |
| 2881 |
| 2882 <dt>[UNICODE]</dt> |
| 2883 <dd><a name="refsUNICODE"></a> <cite><a |
| 2884 href="http://www.unicode.org/versions/Unicode4.1.0/">The Unicode Standard, Ve
rsion 4.1</a></cite>, The Unicode Consortium. Boston, MA, Addison-Wesley, March
2005. ISBN 0-321-18578-1, as amended by <a href="http://www.unicode.org/versions
/Unicode4.0.1/">Unicode 4.0.1</a> and <a href="http://www.unicode.org/versions/U
nicode4.1.0/">Unicode 4.1.0</a>. |
| 2885 <dd>(<code><a href="http://www.unicode.org/versions/">http://www.unicode.org/v
ersions/</a></code>)</dd> |
| 2886 |
| 2887 <dt>[XML10] |
| 2888 <dd><a name="refsXML10"></a> Tim Bray, Jean Paoli, C. M. Sperberg-McQueen, Eve
Maler, François Yergeau, editors; "<cite>Extensible Markup Language (XML
) 1.0 (Third Edition)</cite>", W3C Recommendation, 4 February 2004 |
| 2889 <dd>(<a href="http://www.w3.org/TR/REC-xml/"><code>http://www.w3.org/TR/REC-xm
l/</code></a>) |
| 2890 |
| 2891 <dt>[XMLNAMES] |
| 2892 <dd><a name="refsXMLNAMES"></a> Tim Bray, Dave Hollander, Andrew Layman, edito
rs; "<cite>Namespaces in XML</cite>", W3C Recommendation, 14 January 1999 |
| 2893 <dd>(<a href="http://www.w3.org/TR/REC-xml-names/"><code>http://www.w3.org/TR/
REC-xml-names/</code></a>) |
| 2894 |
| 2895 <dt>[YACC] |
| 2896 <dd><a name="refsYACC"></a> S. C. Johnson; "<cite>YACC — Yet another com
piler compiler</cite>", Technical Report, Murray Hill, 1975 |
| 2897 |
| 2898 </dl> |
| 2899 </body> |
| 2900 </html> |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 9732019:
dart:html perf optimization based on runing Dromaeo benchmarks (Closed)
Base URL: https://dart.googlecode.com/svn/branches/bleeding_edge/dart