add l18n ability

fixes #191

index.html

@@ -33,6 +33,7 @@
 	<script type="text/javascript" src="vendor/vendor.js"></script>
 	<script type="text/javascript" src="modules/default/defaultmodules.js"></script>
 	<script type="text/javascript" src="js/logger.js"></script>
+	<script type="text/javascript" src="js/translator.js"></script>
 	<script type="text/javascript" src="js/class.js"></script>
 	<script type="text/javascript" src="js/module.js"></script>
 	<script type="text/javascript" src="js/loader.js"></script>

js/loader.js

@@ -144,11 +144,13 @@ var Loader = (function() {
 			Log.log("Scripts loaded for: " + module.name);
 			mObj.loadStyles(function() {
 				Log.log("Styles loaded for: " + module.name);
-
+				mObj.loadTranslations(function() {
+					Log.log("Translations loaded for: " + module.name);
 					moduleObjects.push(mObj);
 					callback();
 				});
 			});
+		});
 
 	};
 

js/module.js

@@ -52,6 +52,15 @@ var Module = Class.extend({
 		return [];
 	},
 
+	/* getTranslations()
+	 * Returns a map of translation files the module requires to be loaded.
+	 *
+	 * return Map<String, String> - A map with langKeys and filenames.
+	 */
+	getTranslations: function() {
+		return {};
+	},
+
 	/* getDom()
 	 * This method generates the dom which needs to be displayed. This method is called by the Magic Mirror core.
 	 * This method needs to be subclassed if the module wants to display info on the mirror.
@@ -204,6 +213,32 @@ var Module = Class.extend({
 		loadNextScript();
 	},
 
+	/* loadScripts()
+	 * Load all required scripts by requesting the MM object to load the files.
+	 *
+	 * argument callback function - Function called when done.
+	 */
+	loadTranslations: function(callback) {
+		var self = this;
+		var translations = this.getTranslations();
+		var translationFile = translations && (translations[config.language] || translations["en"]) || undefined;
+		if(translationFile) {
+ 			Translator.load(this, translationFile, callback);
+		} else {
+ 			callback();
+		}
+	},
+
+ 	/* translate(key, defaultValue)
+ 	 * Request the translation for a given key.
+ 	 *
+ 	 * argument key string - The key of the string to translage
+	 * argument defaultValue string - The default value if no translation was found. (Optional)
+ 	 */
+	translate: function(key, defaultValue) {
+		return Translator.translate(this, key) || defaultValue || '';
+	},
+
 	/* updateDom(speed)
 	 * Request an (animated) update of the module.
 	 *

js/translator.js

@@ -0,0 +1,57 @@
+/* exported Translator */
+/* Magic Mirror
+ * Translator (l10n)
+ *
+ * By Christopher Fenner http://github.com/CFenner
+ * MIT Licensed.
+ */
+var Translator = (function() {
+	return {
+		translations: {},
+		/* translate(module, key)
+		 * Load a translation for a given key for a given module.
+		 *
+		 * argument module Module - The module to load the translation for.
+		 * argument key string - The key of the text to translate.
+		 */
+		translate: function(module, key) {
+			if(this.translations[module.name]) {
+				return this.translations[module.name][key];
+			}
+			return undefined;
+		},
+		/* load(module, file, callback)
+		 * Load a translation file (json) and remember the data.
+		 *
+		 * argument module Module - The module to load the translation file for.
+		 * argument file string - Path of the file we want to load.
+		 * argument callback function - Function called when done.
+		 */
+		load: function(module, file, callback) {
+			var self = this;
+			if(!this.translations[module.name]) {
+				this._loadJSON(module.file(file), function(json) {
+					self.translations[module.name] = json;
+					callback();
+				});
+			}
+		},
+		/* _loadJSON(file, callback)
+		 * Load a JSON file via XHR.
+		 *
+		 * argument file string - Path of the file we want to load.
+		 * argument callback function - Function called when done.
+		 */
+		_loadJSON: function(file, callback) {
+		  var xhr = new XMLHttpRequest();
+		  xhr.overrideMimeType("application/json");
+		  xhr.open('GET', file, true);
+		  xhr.onreadystatechange = function () {
+        if (xhr.readyState == 4 && xhr.status == "200") {
+          callback(JSON.parse(xhr.responseText));
+        }
+		  };
+		  xhr.send(null);
+		}
+	};
+})();