Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(542)

Issues Search
    My Issues | Starred     Open | Closed | All

Unified Diff: lib/boot.js

Issue 20863002: Introduce boot.js: this finally makes it possible to load and run Todomvc (Closed) Base URL: git@github.com:dart-lang/web-ui.git@master
Patch Set: Created 7 years, 5 months ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View side-by-side diff with in-line comments
Download patch
« example/todomvc/web/index.html ('K') | « example/todomvc/web/todo_row.dart ('k') | lib/observe.dart » ('j') | lib/observe.dart » ('J')
Expand Comments ('e') | Collapse Comments ('c') | Show Comments Hide Comments ('s')
Index: lib/boot.js
diff --git a/lib/boot.js b/lib/boot.js
new file mode 100644
index 0000000000000000000000000000000000000000..694e51cf4c934e907d30c27974085871a947a0c1
--- /dev/null
+++ b/lib/boot.js
@@ -0,0 +1,175 @@
+// Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// This script dynamically prepares a set of files to run polymer.dart. It uses
+// the html_import polyfill to search for all imported files, then
+// it inlines all <polymer-element> definitions on the top-level page (needed by
+// registerPolymerElement), and it removes script tags that appear inside
+// those tags. It finally rewrites the main entrypoint to call an initialization
+// function on each of the declared <polymer-elements>.
+//
+// This script is needed only when running polymer.dart in Dartium. It should be
+// removed by the polymer deployment commands.
+
+// As an example, given an input of this form:
+// <polymer-element name="c1">
+// <template></template>
+// <script type="application/dart" src="url0.dart"></script>
+// </polymer-element>
+// <element name="c2">
+// <template></template>
+// <script type="application/dart">main() => { print('body2'); }</script>
+// </element>
+// <c1></c1>
+// <c2></c2>
+// <script type="application/dart" src="url2.dart"></script>
+// <script src="packages/polymer/boot.js"></script>
+//
+// This script will simplifies the page as follows:
+// <polymer-element name="c1">
+// <template></template>
+// </polymer-element>
+// <polymer-element name="c2">
+// <template></template>
+// </polymer-element>
+// <c1></c1>
+// <c2></c2>
+// <script type="application/dart">
+// import 'url0.dart' as i0;
+// import "data:application/dart;base64,CiAgICBtYWluKCkgewogICAgICBwcmludCgnYm9keTInKTsKICAgIH0KICAgIA==" as i1;
+// import 'url2.dart' as i2;
+// ...
+// main() {
+// // code that checks which libraries have a 'main' and invokes them.
+// // practically equivalent to: i0._init(); i1._init(); i2.main();
+// }
+// </script>
+
+
+(function() {
+ // Only run in Dartium.
+ if (!navigator.webkitStartDart) return;
Jennifer Messerly 2013/07/27 02:18:44 should we print a console message? "boot.js only
Siggi Cherem (dart-lang) 2013/07/30 00:10:29 Done.
+
+ // Whether [node] is under `<body>` or `<head>` and not nested in an
+ // `<element>` or `<polymer-element>` tag.
+ function isTopLevel(node) {
+ var parent = node.parentNode;
+ if (parent == null || parent == document.body || parent == document.head) {
+ return true;
+ }
+ if (parent.localName && (
+ parent.localName == 'element' ||
+ parent.localName == 'polymer-element')) {
+ return false;
+ }
+ return isTopLevel(parent);
+ }
+
+ // Extract a Dart import URL from a script tag, which is the 'src' attribute
+ // of the script tag, or a data-url with the script contents for inlined code.
+ function getScriptUrl(script) {
+ var url = script.src;
+ if (url && url != '') {
Jennifer Messerly 2013/07/27 02:18:44 second check is unnecessary, empty string is false
Siggi Cherem (dart-lang) 2013/07/30 00:10:29 Done.
+ // Normalize package: urls
+ var index = url.indexOf('packages/');
+ if (index == 0 || (index > 0 && url[index - 1] == '/')) {
+ url = "package:" + url.slice(index + 9);
+ }
+
+ // TODO(sigmund): remove the timestamp. We added this to work around
Jennifer Messerly 2013/07/27 02:18:44 awesome workaround, btw!
+ // a caching bug in dartium (see http://dartbug.com/12074). Note this
+ // doesn't fix caching problems with other libraries imported further in,
+ // and it can also introduce canonicalization problems if the files under
+ // these urls are being imported from other libraries.
+ var time = new Date().getTime();
+ return url + '?' + time;
+ } else {
+ // TODO(sigmund): investigate how to eliminate the warning in Dartium
Jennifer Messerly 2013/07/27 02:18:44 curious, what is the warning?
Siggi Cherem (dart-lang) 2013/07/30 00:10:29 In the console you'd see a message of this form:
+ // (changing to text/javascript hides the warning, but seems wrong).
+ return "data:application/dart;base64," + window.btoa(script.textContent);
+ }
+ }
+
+ // Moves <polymer-elements> from imported documents into the top-level page.
Jennifer Messerly 2013/07/27 02:18:44 does html_imports/polymer do this too? instead of
Siggi Cherem (dart-lang) 2013/07/30 00:10:29 Exactly =), I was planning to do so as a next step
+ function inlinePolymerElements(content, seen) {
+ if (!seen) seen = {};
+ var links = content.querySelectorAll('link[rel="import"]');
+
+ if (content != document) { // no need to do anything for the top-level page
+ var elements = content.querySelectorAll('polymer-element');
+ var ref = document.body.firstChild;
+ for (var i = 0; i < elements.length; ++i) {
+ document.body.insertBefore(elements[i], ref);
+ }
+ }
+
+ for (var i = 0; i < links.length; i++) {
+ var link = links[i].import;
+ if (seen[link.href]) continue;
+ seen[link.href] = link;
+ inlinePolymerElements(link.content, seen);
+ }
+ }
+
+ // Creates a Dart program that imports [urls] and [mainUrl] and invokes the
+ // _init methods of each library in urls (if present) followed by the main
+ // method of [mainUrl].
+ function createMain(urls, mainUrl) {
+ var imports = Array(urls.length + 2);
+ for (var i = 0; i < urls.length; ++i) {
+ imports[i] = 'import "' + urls[i] + '" as i' + i + ';';
+ }
+ imports[urls.length] = 'import "package:polymer/polymer.dart" as polymer;';
+ imports[urls.length + 1 ] = 'import "' + mainUrl + '" as userMain;';
+ return (imports.join('\n') +
+ '\n\nmain() {\n' +
+ ' polymer.initializePolymer([\n' +
+ ' "' + urls.join('",\n "') + '"\n ], userMain.main);\n' +
+ '}\n');
+ }
+
+ // Finds all top-level <script> tags, and <script> tags in custom elements
+ // and merges them into a single entrypoint.
+ function mergeScripts() {
+ var scripts = document.getElementsByTagName("script");
+ var length = scripts.length;
+
+ var dartScripts = []
+ var urls = [];
+
+ // Collect the information we need to replace the script tags
+ for (var i = 0; i < length; ++i) {
+ var script = scripts[i];
+ if (script.type == "application/dart") {
+ dartScripts.push(script);
+ if (isTopLevel(script)) continue;
+ urls.push(getScriptUrl(script));
+ }
+ }
+
+ if (urls.length > 0) {
+ // Removes all the original script tags under elements, and replace
+ // top-level script tags so we first call each element's _init.
+ for (var i = 0; i < dartScripts.length; ++i) {
+ var script = dartScripts[i];
+ if (isTopLevel(script)) {
+ var newScript = document.createElement('script');
+ newScript.type = "application/dart";
+ newScript.textContent = createMain(urls, getScriptUrl(script));
+ script.parentNode.replaceChild(newScript, script);
+ } else {
+ script.parentNode.removeChild(script);
+ }
+ }
+ }
+ }
+
+ window.addEventListener('HTMLImportsLoaded', function (e) {
+ inlinePolymerElements(document);
+ mergeScripts();
+ if (!navigator.webkitStartDart()) {
+ document.body.innerHTML = 'This build has expired. Please download a new Dartium at http://www.dartlang.org/dartium/index.html';
+ }
+ });
+})();
« example/todomvc/web/index.html ('K') | « example/todomvc/web/todo_row.dart ('k') | lib/observe.dart » ('j') | lib/observe.dart » ('J')

Powered by Google App Engine
This is Rietveld 408576698