add lazyload.js

html/js/lazyload.js

@@ -0,0 +1,36 @@
+/*
+   * LibreNMS module to initialize and support lazy loading of graph images
+   *
+   * Copyright (c) 2015 Travis Hegner <http://travishegner.com/>
+   *
+   * This program is free software: you can redistribute it and/or modify it
+   * under the terms of the GNU General Public License as published by the
+   * Free Software Foundation, either version 3 of the License, or (at your
+   * option) any later version.  Please see LICENSE.txt at the top level of
+   * the source code distribution for details.
+   */
+$(document).ready(function(){
+    
+    //initialize jquery lazyload for all '.lazy' img tags
+    $("img.lazy").load(lazyload_done).lazyload({
+        effect: "fadeIn",
+        threshold: 300,
+        placeholder: ""
+    });
+
+
+    //re-initializes images loaded after an ajax call
+    $(document).ajaxStop(function() {
+        $("img.lazy").load(lazyload_done).lazyload({
+            effect: "fadeIn",
+            threshold: 300,
+            placeholder: ""
+        });
+    });
+});
+
+function lazyload_done() {
+    //Since RRD takes the width and height params for only the canvas, we must unset them 
+    //from the final (larger) image to prevent the browser from resizing them.
+    $(this).removeAttr('width').removeAttr('height').removeClass('lazy');
+}