Added callback function to lazy load plugin so templates can do things once the image has been lazy loaded.

ignite-html-lazyload.js

@@ -59,9 +59,10 @@ class IgniteLazyLoad {
 /**
  * Lazy loads an image in the src attribute for this element.
  * @param {string|Function|IgniteProperty} placeholder The palceholder image to use before the image is loaded. If null, a default one will be used.
+ * @param {Function|IgniteProperty} callback The callback function to invoke once the image has been lazy loaded in. By default null.
  * @returns {IgniteTemplate} This ignite template.
  */
-IgniteTemplate.prototype.lazy = function (placeholder = null) {
+IgniteTemplate.prototype.lazy = function (placeholder = null, callback = null) {
     //See if we have a src attribute already defined.
     if (this._attributes["src"]) {
         //Save the original source.
@@ -88,6 +89,13 @@ IgniteTemplate.prototype.lazy = function (placeholder = null) {
                     this._attributes["src"] = this._lazy_src;
                     this.element.setAttribute("src", this._lazy_src);
                     this._lazy_src = null;
+ 
+                    //If we have a callback invoke it.
+                    if (callback instanceof IgniteProperty) {
+                        callback.value();
+                    } else if (callback instanceof Function) {
+                        callback();
+                    }
                 }
             });
         });