Update network/node image code to allow for specifying a broken image url to use when a node image fails to load

.gitignore

@@ -7,3 +7,4 @@ node_modules
 .settings/org.eclipse.wst.jsdt.ui.superType.name
 npm-debug.log
 examples/graph/24_hierarchical_layout_userdefined2.html
+.DS_Store

lib/network/Images.js

@@ -20,9 +20,10 @@ Images.prototype.setOnloadCallback = function(callback) {
 /**
  *
  * @param {string} url          Url of the image
+ * @param {string} url          Url of an image to use if the url image is not found
  * @return {Image} img          The image object
  */
-Images.prototype.load = function(url) {
+Images.prototype.load = function(url, brokenUrl) {
   var img = this.images[url];
   if (img == undefined) {
     // create the image
@@ -34,6 +35,14 @@ Images.prototype.load = function(url) {
         images.callback(this);
       }
     };
+    
+    img.onerror = function () {
+	  this.src = brokenUrl;
+	  if (images.callback) {
+		images.callback(this);
+	  }
+	};
+	
     img.src = url;
   }
 

lib/network/Node.js

@@ -135,7 +135,7 @@ Node.prototype.setProperties = function(properties, constants) {
     return;
   }
 
-  var fields = ['borderWidth','borderWidthSelected','shape','image','radius','fontColor',
+  var fields = ['borderWidth','borderWidthSelected','shape','image','brokenImage','radius','fontColor',
     'fontSize','fontFace','fontFill','group','mass'
   ];
   util.selectiveDeepExtend(fields, this.options, properties);
@@ -176,7 +176,7 @@ Node.prototype.setProperties = function(properties, constants) {
 
   if (this.options.image!== undefined && this.options.image!= "") {
     if (this.imagelist) {
-      this.imageObj = this.imagelist.load(this.options.image);
+      this.imageObj = this.imagelist.load(this.options.image, this.options.brokenImage);
     }
     else {
       throw "No imagelist provided";