Bug 416446 - Make PluralForm more useful for extensions and delay importing strings for perf. r=sdwilsh, r=smontagu, a1.9=damons

intl/locale/src/PluralForm.jsm

@@ -39,7 +39,10 @@ EXPORTED_SYMBOLS = [ "PluralForm" ];
 /**
  * This module provides the PluralForm object which contains a method to figure
  * out which plural form of a word to use for a given number based on the
- * current localization.
+ * current localization. There is also a makeGetter method that creates a get
+ * function for the desired plural rule. This is useful for extensions that
+ * specify their own plural rule instead of relying on the browser default.
+ * (I.e., the extension hasn't been localized to the browser's locale.)
  *
  * See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
  *
@@ -50,6 +53,10 @@ EXPORTED_SYMBOLS = [ "PluralForm" ];
  *
  * int numForms
  * numForms()
+ *
+ * [string pluralForm get(int aNum, string aWords), int numForms numForms()]
+ * makeGetter(int aRuleNum)
+ * Note: Basically, makeGetter returns 2 functions that do "get" and "numForm"
  */
 
 const Cc = Components.classes;
@@ -93,8 +100,6 @@ let gFunctions = [
   [3, function(n) n%10==1?0:n%10==2?1:2],
 ];
 
-let gNumForms;
-
 let PluralForm = {
   /**
    * Get the correct plural form of a word based on the number
@@ -105,30 +110,49 @@ let PluralForm = {
    *        A semi-colon (;) separated string of words to pick the plural form
    * @return The appropriate plural form of the word
    */
-  get: (function initGetPluralForm()
+  get get()
   {
-    // initGetPluralForm gets called right away when this module is loaded and
+    // This method will lazily load to avoid perf when it is first needed and
     // creates getPluralForm function. The function it creates is based on the
     // value of pluralRule specified in the intl stringbundle.
     // See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
 
+    // Delete the getters to be overwritten
+    delete PluralForm.numForms;
+    delete PluralForm.get;
+
     // Get the plural rule number from the intl stringbundle
     let ruleNum = Number(Cc["@mozilla.org/intl/stringbundle;1"].
       getService(Ci.nsIStringBundleService).createBundle(kIntlProperties).
       GetStringFromName("pluralRule"));
 
+    // Make the plural form get function and set it as the default get
+    [PluralForm.get, PluralForm.numForms] = PluralForm.makeGetter(ruleNum);
+    return PluralForm.get;
+  },
+
+  /**
+   * Create a pair of plural form functions for the given plural rule number.
+   *
+   * @param aRuleNum
+   *        The plural rule number to create functions
+   * @return A pair: [function that gets the right plural form,
+   *                  function that returns the number of plural forms]
+   */
+  makeGetter: function(aRuleNum)
+  {
     // Default to "all plural" if the value is out of bounds or invalid
-    if (ruleNum < 0 || ruleNum >= gFunctions.length || isNaN(ruleNum)) {
-      log(["Invalid rule number: ", ruleNum, " -- defaulting to 0"]);
-      ruleNum = 0;
+    if (aRuleNum < 0 || aRuleNum >= gFunctions.length || isNaN(aRuleNum)) {
+      log(["Invalid rule number: ", aRuleNum, " -- defaulting to 0"]);
+      aRuleNum = 0;
     }
 
     // Get the desired pluralRule function
-    let pluralFunc;
-    [gNumForms, pluralFunc] = gFunctions[ruleNum];
+    let [numForms, pluralFunc] = gFunctions[aRuleNum];
 
-    // Return a function that gets the right plural form
-    return function(aNum, aWords) {
+    // Return functions that give 1) the number of forms and 2) gets the right
+    // plural form
+    return [function(aNum, aWords) {
       // Figure out which index to use for the semi-colon separated words
       let index = pluralFunc(aNum ? Number(aNum) : 0);
       let words = aWords ? aWords.split(/;/) : [""];
@@ -139,26 +163,31 @@ let PluralForm = {
       // Check for array out of bounds or empty strings
       if ((ret == undefined) || (ret == "")) {
         // Report the caller to help figure out who is causing badness
-        let caller = this.get.caller ? this.get.caller.name : "top";
+        let caller = PluralForm.get.caller ? PluralForm.get.caller.name : "top";
 
         // Display a message in the error console
         log(["Index #", index, " of '", aWords, "' for value ", aNum,
-            " is invalid -- plural rule #", ruleNum, "; called by ", caller]);
+            " is invalid -- plural rule #", aRuleNum, "; called by ", caller]);
 
         // Default to the first entry (which might be empty, but not undefined)
         ret = words[0];
       }
 
       return ret;
-    };
-  })(),
+    }, function() numForms];
+  },
 
   /**
    * Get the number of forms for the current plural rule
    *
    * @return The number of forms
    */
-  numForms: function() gNumForms,
+  get numForms()
+  {
+    // We lazily load numForms, so trigger the init logic with get()
+    PluralForm.get();
+    return PluralForm.numForms;
+  },
 };
 
 /**

intl/locale/tests/unit/test_pluralForm_makeGetter.js

@@ -0,0 +1,68 @@
+/* ***** BEGIN LICENSE BLOCK *****
+ *   Version: MPL 1.1/GPL 2.0/LGPL 2.1
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Plural Form l10n Test Code.
+ *
+ * The Initial Developer of the Original Code is
+ * Edward Lee <edward.lee@engineering.uiuc.edu>.
+ * Portions created by the Initial Developer are Copyright (C) 2008
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * either the GNU General Public License Version 2 or later (the "GPL"), or
+ * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
+ * in which case the provisions of the GPL or the LGPL are applicable instead
+ * of those above. If you wish to allow use of your version of this file only
+ * under the terms of either the GPL or the LGPL, and not to allow others to
+ * use your version of this file under the terms of the MPL, indicate your
+ * decision by deleting the provisions above and replace them with the notice
+ * and other provisions required by the GPL or the LGPL. If you do not delete
+ * the provisions above, a recipient may use your version of this file under
+ * the terms of any one of the MPL, the GPL or the LGPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+/**
+ * This unit test makes sure the plural form for Irish Gaeilge is working by
+ * using the makeGetter method instead of using the default language (by
+ * development), English.
+ */
+
+Components.utils.import("resource://gre/modules/PluralForm.jsm");
+
+function run_test()
+{
+  // Irish is plural rule #11
+  let [get, numForms] = PluralForm.makeGetter(11);
+
+  // Irish has 5 plural forms
+  do_check_eq(5, numForms());
+
+  // I don't really know Irish, so I'll stick in some dummy text
+  let words = "is 1;is 2;is 3-6;is 7-10;everything else";
+
+  let test = function(text, low, high) {
+    for (let num = low; num <= high; num++)
+      do_check_eq(text, get(num, words));
+  };
+
+  // Make sure for good inputs, things work as expected
+  test("everything else", 0, 0);
+  test("is 1", 1, 1);
+  test("is 2", 2, 2);
+  test("is 3-6", 3, 6);
+  test("is 7-10", 7, 10);
+  test("everything else", 11, 200);
+}