add events to strategy.save: start, success, fail. r=elemoine, (Closes #1902)

(It is possible Save may need extension for additional events; this should be
a new ticket.)


git-svn-id: http://svn.openlayers.org/trunk/openlayers@9645 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Strategy/Save.js

@@ -18,6 +18,28 @@
  */
 OpenLayers.Strategy.Save = OpenLayers.Class(OpenLayers.Strategy, {
     
+    /**
+     * Constant: EVENT_TYPES
+     * {Array(String)} Supported application event types.  Register a listener
+     *     for a particular event with the following syntax:
+     * (code)
+     * protocol.events.register(type, obj, listener);
+     * (end)
+     *
+     *  - *start* Triggered before saving
+     *  - *success* Triggered after a successful transaction
+     *  - *fail* Triggered after a failed transaction
+     *      
+     */
+    EVENT_TYPES: ["start", "success", "fail"],
+ 
+    /** 
+     * Property: events
+     * {<OpenLayers.Events>} Events instance for triggering this protocol
+     *    events.
+     */
+    events: null,
+    
     /**
      * APIProperty: auto
      * {Boolean | Number} Auto-save.  Default is false.  If true, features will be
@@ -43,6 +65,7 @@ OpenLayers.Strategy.Save = OpenLayers.Class(OpenLayers.Strategy, {
      */
     initialize: function(options) {
         OpenLayers.Strategy.prototype.initialize.apply(this, [options]);
+        this.events = new OpenLayers.Events(this, null, this.EVENT_TYPES);
     },
    
     /**
@@ -131,6 +154,7 @@ OpenLayers.Strategy.Save = OpenLayers.Class(OpenLayers.Strategy, {
         if(!features) {
             features = this.layer.features;
         }
+        this.events.triggerEvent("start", {features:features});
         var remote = this.layer.projection;
         var local = this.layer.map.getProjectionObject();
         if(!local.equals(remote)) {
@@ -162,6 +186,7 @@ OpenLayers.Strategy.Save = OpenLayers.Class(OpenLayers.Strategy, {
      * response - {<OpenLayers.Protocol.Response>} A response object.
      */
     onCommit: function(response) {
+        var evt = {"response": response};
         if(response.success()) {
             var features = response.reqFeatures;
             // deal with inserts, updates, and deletes
@@ -184,11 +209,17 @@ OpenLayers.Strategy.Save = OpenLayers.Class(OpenLayers.Strategy, {
                     feature.state = null;
                 }
             }
+
             if(destroys.length > 0) {
                 this.layer.destroyFeatures(destroys);
             }
+
+            this.events.triggerEvent("success", evt);
+
+        } else {
+            this.events.triggerEvent("fail", evt);
         }
-    },    
+    },
    
     CLASS_NAME: "OpenLayers.Strategy.Save" 
 });