Adding DateTimeFormat class to i18n API.

src/extensions/experimental/i18n.js

Index: src/extensions/experimental/i18n.js
===================================================================
--- src/extensions/experimental/i18n.js	(revision 7878)
+++ src/extensions/experimental/i18n.js	(working copy)
@@ -45,11 +45,11 @@
   }
 
   var properties = NativeJSLocale(
-      v8Locale.createSettingsOrDefault_(settings, {'localeID': 'root'}));
+      v8Locale.__createSettingsOrDefault(settings, {'localeID': 'root'}));
 
   // Keep the resolved ICU locale ID around to avoid resolving localeID to
   // ICU locale ID every time BreakIterator, Collator and so forth are called.
-  this.__icuLocaleID__ = properties.icuLocaleID;
+  this.__icuLocaleID = properties.icuLocaleID;
   this.options = {'localeID': properties.localeID,
                   'regionID': properties.regionID};
 };
@@ -61,7 +61,7 @@
  */
 v8Locale.prototype.derive = function(settings) {
   return new v8Locale(
-      v8Locale.createSettingsOrDefault_(settings, this.options));
+      v8Locale.__createSettingsOrDefault(settings, this.options));
 };
 
 /**
@@ -79,9 +79,9 @@
 v8Locale.v8BreakIterator = function(locale, type) {
   native function NativeJSBreakIterator();
 
-  locale = v8Locale.createLocaleOrDefault_(locale);
+  locale = v8Locale.__createLocaleOrDefault(locale);
   // BCP47 ID would work in this case, but we use ICU locale for consistency.
-  var iterator = NativeJSBreakIterator(locale.__icuLocaleID__, type);
+  var iterator = NativeJSBreakIterator(locale.__icuLocaleID, type);
   iterator.type = type;
   return iterator;
 };
@@ -122,22 +122,103 @@
 v8Locale.Collator = function(locale, settings) {
   native function NativeJSCollator();
 
-  locale = v8Locale.createLocaleOrDefault_(locale);
+  locale = v8Locale.__createLocaleOrDefault(locale);
   var collator = NativeJSCollator(
-      locale.__icuLocaleID__, v8Locale.createSettingsOrDefault_(settings, {}));
+      locale.__icuLocaleID, v8Locale.__createSettingsOrDefault(settings, {}));
   return collator;
 };
 
 /**
  * Creates new Collator based on current locale.
  * @param {Object} - collation flags. See constructor.
- * @returns {Object} - new v8BreakIterator object.
+ * @returns {Object} - new Collator object.
  */
 v8Locale.prototype.createCollator = function(settings) {
   return new v8Locale.Collator(this, settings);
 };
 
 /**
+ * DateTimeFormat class implements locale-aware date and time formatting.
+ * Constructor is not part of public API.
+ * @param {Object} locale - locale object to pass to formatter.
+ * @param {Object} settings - formatting flags:
+ *   - skeleton
+ *   - dateType
+ *   - timeType
+ *   - calendar
+ * @constructor
+ */
+v8Locale.__DateTimeFormat = function(locale, settings) {
+  native function NativeJSDateTimeFormat();
+
+  settings = v8Locale.__createSettingsOrDefault(settings, {});
+
+  var cleanSettings = {};
+  if (settings.hasOwnProperty('skeleton')) {
+    cleanSettings['skeleton'] = settings['skeleton'];
+  } else {
+    cleanSettings = {};
+    if (settings.hasOwnProperty('dateType')) {
+      var dt = settings['dateType'].toLowerCase();

[jungshik at Google, 2011/05/19 18:24:05]

hmm.... I don't think it's a good idea to call toLowerCase() here. V8's
toLowerCase is ok as it is now for this use case, but ....


 I'd rather not accept anything but 'long', 'short' and 'v8full', 'v8medium')
because I don't see any reason to be lenient for dateType values. 

[Nebojša Ćirić, 2011/05/19 20:44:41]

Done.

+      if (dt !== 'short' && dt !== 'long') dt = 'short';
+      cleanSettings['dateType'] = dt;
+    }
+
+    if (settings.hasOwnProperty('timeType')) {
+      var tt = settings['timeType'].toLowerCase();
+      if (tt !== 'short' && tt !== 'medium') tt = 'short';
+      cleanSettings['timeType'] = tt;
+    }
+  }
+
+  // Default is to show short date and time.
+  if (!cleanSettings.hasOwnProperty('skeleton') &&
+      !cleanSettings.hasOwnProperty('dateType') &&
+      !cleanSettings.hasOwnProperty('timeType')) {
+    cleanSettings = {'dateType': 'short',
+                     'timeType': 'short'};
+  }
+
+  locale = v8Locale.__createLocaleOrDefault(locale);
+  var formatter = NativeJSDateTimeFormat(locale.__icuLocaleID, cleanSettings);
+
+  // NativeJSDateTimeFormat creates formatter.options for us, we just need
+  // to append actual settings to it.
+  for (key in cleanSettings) {
+    formatter.options[key] = cleanSettings[key];
+  }
+
+  /**
+   * Clones existing date time format with possible overrides for some
+   * of the options.
+   * @param {!Object} overrideSettings - overrides for current format settings.
+   * @returns {Object} - new DateTimeFormat object.
+   */
+  formatter.derive = function(overrideSettings) {
+    // To remove a setting user can specify undefined as its value. We'll remove
+    // it from the map in that case.
+    for (var prop in overrideSettings) {
+      if (settings.hasOwnProperty(prop) && !overrideSettings[prop]) {
+        delete settings[prop];
+      }
+    }
+    return new v8Locale.__DateTimeFormat(
+        locale, v8Locale.__createSettingsOrDefault(overrideSettings, settings));
+  };
+
+  return formatter;
+};
+
+/**
+ * Creates new DateTimeFormat based on current locale.
+ * @param {Object} - formatting flags. See constructor.
+ * @returns {Object} - new DateTimeFormat object.
+ */
+v8Locale.prototype.createDateTimeFormat = function(settings) {
+  return new v8Locale.__DateTimeFormat(this, settings);
+};
+
+/**
  * Merges user settings and defaults.
  * Settings that are not of object type are rejected.
  * Actual property values are not validated, but whitespace is trimmed if they
@@ -146,7 +227,7 @@
  * @param {!Object} defaults - default values for this type of settings.
  * @returns {Object} - valid settings object.
  */
-v8Locale.createSettingsOrDefault_ = function(settings, defaults) {
+v8Locale.__createSettingsOrDefault = function(settings, defaults) {
   if (!settings || typeof(settings) !== 'object' ) {
     return defaults;
   }
@@ -155,11 +236,17 @@
       settings[key] = defaults[key];
     }
   }
-  // Clean up values, like trimming whitespace.
+  // Clean up settings.
   for (var key in settings) {
+    // Trim whitespace.
     if (typeof(settings[key]) === "string") {
       settings[key] = settings[key].trim();
     }
+    // Remove all properties that are set to undefined/null. This allows
+    // derive method to remove a setting we don't need anymore.
+    if (!settings[key]) {
+      delete settings[key];
+    }
   }
 
   return settings;
@@ -171,7 +258,7 @@
  * @param {!Object} locale - user provided locale.
  * @returns {Object} - v8Locale object.
  */
-v8Locale.createLocaleOrDefault_ = function(locale) {
+v8Locale.__createLocaleOrDefault = function(locale) {
   if (!locale || !(locale instanceof v8Locale)) {
     return new v8Locale();
   } else {