Add async initialization for Intl.message and an example

pkg/intl/intl.dart

Index: pkg/intl/intl.dart
===================================================================
--- pkg/intl/intl.dart	(revision 12224)
+++ pkg/intl/intl.dart	(working copy)
@@ -8,10 +8,11 @@
  */
 #library('intl');
 
-#import('../../pkg/htmlescape/htmlescape.dart');
+#import('../htmlescape/htmlescape.dart');
 
 #import('date_format.dart');
-#source('intl_message.dart');
+#import('lib/intl_helpers.dart');

[Emily Fortuna, 2012/09/12 01:23:48]

I don't see any "intl_helpers.dart" did this not get added to the repo?

[Alan Knight, 2012/09/12 20:58:20]

It's in the /lib directory, but should be there.
http://code.google.com/p/dart/source/browse/branches/bleeding_edge/dart/pkg/i...

+
 #source('bidi_formatter.dart');
 #source('bidi_utils.dart');
 
@@ -20,36 +21,34 @@
    * String indicating the locale code with which the message is to be
    * formatted (such as en-CA).
    */
-  static String _locale;
+  String _locale;
 
-  IntlMessage intlMsg;
+  /** The default locale, which normally will be obtained from the browser. */
+  static String _defaultLocale;
 
   /**
    * Return a new date format using the specified [pattern].
    * If [desiredLocale] is not specified, then we default to [locale].
    */
-  DateFormat date(String pattern, [String desiredLocale]) {
-    var actualLocale = (desiredLocale == null) ? _locale : desiredLocale;
+  DateFormat date([String pattern, String desiredLocale]) {
+    var actualLocale = (desiredLocale == null) ? locale : desiredLocale;
     return new DateFormat(pattern, actualLocale);
   }
 
   /**
-   * Constructor optionally [_locale] for specifics of the language
+   * Constructor optionally [aLocale] for specifics of the language
    * locale to be used, otherwise, we will attempt to infer it (acceptable if
    * Dart is running on the client, we can infer from the browser/client
    * preferences).
    */
-  Intl([a_locale]) {
-    if (a_locale == null) {
-      _locale = _getDefaultLocale();
-    } else {
-      _locale = verifiedLocale(a_locale);
+  Intl([String aLocale]) {
+    if (aLocale != null) {
+      _locale = aLocale;

[Emily Fortuna, 2012/09/12 01:23:48]

why not set a default here? then you don't have to do those extra checks later
in this class.

[Alan Knight, 2012/09/12 20:58:20]

Done.

     }
-    intlMsg = new IntlMessage(_locale);
   }
 
   /**
-   * Create a message that can be internationalized. It takes a
+   * Returns a message that can be internationalized. It takes a
    * [message_str] that will be translated, which may be interpolated
    * based on one or more variables, a [desc] providing a description of usage
    * for the [message_str], and a map of [examples] for each data element to be
@@ -62,17 +61,26 @@
    * The expected usage of this is inside a function that takes as parameters
    * the variables used in the interpolated string, and additionally also a
    * locale (optional).
+   * Ultimately, the information about the enclosing function and its arguments
+   * will be extracted automatically but for the time being it must be passed
+   * explicitly in the [name] and [args] arguments.
    */
   static String message(String message_str, [final String desc='',
-                        final Map examples=const {}, String locale='']) {
-    return message_str;
+    final Map examples=const {}, String locale, String name,

[Emily Fortuna, 2012/09/12 01:23:48]

indent at least two more spaces here

[Alan Knight, 2012/09/12 20:58:20]

Done.

+    List<String> args]) {
+      return _messageLookup.

[Emily Fortuna, 2012/09/12 01:23:48]

do the line break at the opening of the ( please instead of the .

[Emily Fortuna, 2012/09/12 01:23:48]

indent two less spaces here

[Alan Knight, 2012/09/12 20:58:20]

Done.

[Alan Knight, 2012/09/12 20:58:20]

Done.

+          lookupMessage(message_str, desc, examples, locale, name, args);
   }
 
   /**
    * Return the locale for this instance. If none was set, the locale will
    * be the default.
    */
-  String get locale => _locale;
+  String get locale {
+    if (_locale == null) {
+      _locale = _getDefaultLocale();}
+    return _locale;
+  }
 
   /**
    * Return true if the locale exists, or if it is null. The null case
@@ -143,11 +151,11 @@
   static String withLocale(String locale, Function msg_function) {
     // We have to do this silliness because Locale is not known at compile time,
     // but must be a static variable.
-    if (_locale == null) _locale = _getDefaultLocale();
-    var oldLocale = _locale;
-    _locale = locale;
+    if (_defaultLocale == null) _defaultLocale = _getDefaultLocale();
+    var oldLocale = _defaultLocale;
+    _defaultLocale = locale;
     var result = msg_function();
-    _locale = oldLocale;
+    _defaultLocale = oldLocale;
     return result;
   }
 
@@ -182,6 +190,24 @@
    * locale.
    */
   static String getCurrentLocale() {
-    return _locale;
+    if (_defaultLocale == null) _defaultLocale = _getDefaultLocale();
+    return _defaultLocale;
   }
 }
+
+/** The internal mechanism for looking up messages. We expect this to be set

[Emily Fortuna, 2012/09/12 01:23:48]

/**
 * The internal....
 */

[Alan Knight, 2012/09/12 20:58:20]

Done.

+ * by the implementing package so that we're not dependent on its
+ * implementation.
+ */
+var _messageLookup = const
+    UninitializedLocaleData('initializeMessages(<locale>)');
+
+/** Initialize the message lookup mechanism. This is for internal use only.

[Emily Fortuna, 2012/09/12 01:23:48]

same formatting here

[Alan Knight, 2012/09/12 20:58:20]

Done.

+ * User applications should import message_lookup_local.dart and call
+ * initializeMessages
+ */
+void initializeInternalMessageLookup(Function lookupFunction) {
+  if (_messageLookup is UninitializedLocaleData) {
+    _messageLookup = lookupFunction();
+  }
+}