GUAC-1172: Implement JSONreader for convenience.

guacamole-common-js/src/main/webapp/modules/JSONReader.js

@@ -0,0 +1,117 @@
+/*
+ * Copyright (C) 2015 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+var Guacamole = Guacamole || {};
+
+/**
+ * A reader which automatically handles the given input stream, assembling all
+ * received blobs into a JavaScript object by appending them to each other, in
+ * order, and decoding the result as JSON. Note that this object will overwrite
+ * any installed event handlers on the given Guacamole.InputStream.
+ * 
+ * @constructor
+ * @param {Guacamole.InputStream} stream
+ *     The stream that JSON will be read from.
+ */
+Guacamole.JSONReader = function(stream) {
+
+    /**
+     * Reference to this Guacamole.JSONReader.
+     *
+     * @private
+     * @type Guacamole.JSONReader
+     */
+    var guacReader = this;
+
+    /**
+     * Wrapped Guacamole.StringReader.
+     *
+     * @private
+     * @type Guacamole.StringReader
+     */
+    var stringReader = new Guacamole.StringReader(stream);
+
+    /**
+     * All JSON read thus far.
+     *
+     * @private
+     * @type String
+     */
+    var json = '';
+
+    /**
+     * Returns the current length of this Guacamole.JSONReader, in characters.
+     *
+     * @return {Number}
+     *     The current length of this Guacamole.JSONReader.
+     */
+    this.getLength = function() {
+        return json.length;
+    };
+
+    /**
+     * Returns the contents of this Guacamole.JSONReader as a JavaScript
+     * object.
+     *
+     * @return {Object}
+     *     The contents of this Guacamole.JSONReader, as parsed from the JSON
+     *     contents of the input stream.
+     */
+    this.getJSON = function() {
+        return JSON.parse(json);
+    };
+
+    // Append all received text
+    stringReader.ontext = function ontext(text) {
+
+        // Append received text
+        json += text;
+
+        // Call handler, if present
+        if (guacReader.onprogress)
+            guacReader.onprogress(text.length);
+
+    };
+
+    // Simply call onend when end received
+    stringReader.onend = function() {
+        if (guacReader.onend)
+            guacReader.onend();
+    };
+
+    /**
+     * Fired once for every blob of data received.
+     * 
+     * @event
+     * @param {Number} length
+     *     The number of characters received.
+     */
+    this.onprogress = null;
+
+    /**
+     * Fired once this stream is finished and no further data will be written.
+     *
+     * @event
+     */
+    this.onend = null;
+
+};