GUACAMOLE-36: Define REST API transfer mechanism for translatable messages.

guacamole/src/main/webapp/app/rest/types/Error.js

@@ -42,6 +42,15 @@ angular.module('rest').factory('Error', [function defineError() {
          */
         this.message = template.message;
 
+        /**
+         * A message which can be translated using the translation service,
+         * consisting of a translation key and optional set of substitution
+         * variables.
+         *
+         * @type TranslatableMessage
+         */
+        this.translatableMessage = template.translatableMessage;
+
         /**
          * The Guacamole protocol status code associated with the error that
          * occurred. This is only valid for errors of type STREAM_ERROR.

guacamole/src/main/webapp/app/rest/types/TranslatableMessage.js

@@ -0,0 +1,63 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+/**
+ * Service which defines the TranslatableMessage class.
+ */
+angular.module('rest').factory('TranslatableMessage', [function defineTranslatableMessage() {
+
+    /**
+     * The object returned by REST API calls when representing a message which
+     * can be translated using the translation service, providing a translation
+     * key and optional set of values to be substituted into the translation
+     * string associated with that key.
+     *
+     * @constructor
+     * @param {TranslatableMessage|Object} [template={}]
+     *     The object whose properties should be copied within the new
+     *     TranslatableMessage.
+     */
+    var TranslatableMessage = function TranslatableMessage(template) {
+
+        // Use empty object by default
+        template = template || {};
+
+        /**
+         * The key associated with the translation string that used when
+         * displaying this message.
+         *
+         * @type String
+         */
+        this.key = template.key;
+
+        /**
+         * The object which should be passed through to the translation service
+         * for the sake of variable substitution. Each property of the provided
+         * object will be substituted for the variable of the same name within
+         * the translation string.
+         *
+         * @type Object
+         */
+        this.variables = template.variables;
+
+    };
+
+    return TranslatableMessage;
+
+}]);