From 12998d2fea89201e82347ae4c51f7003067ae287 Mon Sep 17 00:00:00 2001
From: Thomas Perl <m@thp.io>
Date: Wed, 15 Apr 2015 14:04:44 +0200
Subject: [PATCH] Add support for fallbackLanguage

This is useful for situations where ID-based translations
are used and where a fallback to another language is desirable.

Example:

* Source strings are ID-based, e.g. `LABEL_SOMETHING`
* Strings are translated to English: e.g. "Something"
* Strings are translated to German, but missing some translations

Setting:

```
gettextContext.setCurrentLanguage('de');
gettextContext.setFallbackLanguage('en');
```

Should then return the English string if the German string is not
available (e.g. `LABEL_SOMETHING` returns "Something" in German).
---
 src/catalog.js | 22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/catalog.js b/src/catalog.js
index c6e776e..70dd72d 100644
--- a/src/catalog.js
+++ b/src/catalog.js
@@ -38,6 +38,7 @@ angular.module('gettext').factory('gettextCatalog', function (gettextPlurals, $h
         strings: {},
         baseLanguage: 'en',
         currentLanguage: 'en',
+        fallbackLanguage: undefined,
         cache: $cacheFactory('strings'),
 
         setCurrentLanguage: function (lang) {
@@ -49,6 +50,15 @@ angular.module('gettext').factory('gettextCatalog', function (gettextPlurals, $h
             return this.currentLanguage;
         },
 
+        setFallbackLanguage: function (lang) {
+            this.fallbackLanguage = lang;
+            broadcastUpdated();
+        },
+
+        getFallbackLanguage: function () {
+            return this.fallbackLanguage;
+        },
+
         setStrings: function (language, strings) {
             if (!this.strings[language]) {
                 this.strings[language] = {};
@@ -80,13 +90,21 @@ angular.module('gettext').factory('gettextCatalog', function (gettextPlurals, $h
             broadcastUpdated();
         },
 
-        getStringForm: function (string, n, context) {
-            var stringTable = this.strings[this.currentLanguage] || {};
+        getStringFormLanguage: function (string, n, context, lang) {
+            var stringTable = this.strings[lang] || {};
             var contexts = stringTable[string] || {};
             var plurals = contexts[context || noContext] || [];
             return plurals[n];
         },
 
+        getStringForm: function (string, n, context) {
+            var result = this.getStringFormLanguage(string, n, context, this.currentLanguage);
+            if (!result && this.fallbackLanguage) {
+                result = this.getStringFormLanguage(string, n, context, this.fallbackLanguage);
+            }
+            return result;
+        },
+
         getString: function (string, scope, context) {
             string = this.getStringForm(string, 0, context) || prefixDebug(string);
             string = scope ? $interpolate(string)(scope) : string;