#1774 Ability to cancel a Protocol request, r=fredj (closes #1774)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@8420 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Protocol.js

@@ -139,6 +139,16 @@ OpenLayers.Protocol = OpenLayers.Class({
      */
     commit: function() {
     },
+
+    /**
+     * Method: abort
+     * Abort an ongoing request.
+     *
+     * Parameters:
+     * response - {<OpenLayers.Protocol.Response>}
+     */
+    abort: function(response) {
+    },
    
     CLASS_NAME: "OpenLayers.Protocol" 
 });

lib/OpenLayers/Protocol/HTTP.js

@@ -441,6 +441,21 @@ OpenLayers.Protocol.HTTP = OpenLayers.Class(OpenLayers.Protocol, {
         return resp;
     },
 
+    /**
+     * Method: abort
+     * Abort an ongoing request, the response object passed to
+     * this method must come from this HTTP protocol (as a result
+     * of a create, read, update, delete or commit operation).
+     *
+     * Parameters:
+     * response - {<OpenLayers.Protocol.Response>}
+     */
+    abort: function(response) {
+        if (response) {
+            response.priv.abort();
+        }
+    },
+
     /**
      * Method: callUserCallback
      * This method is used from within the commit method each time an

lib/OpenLayers/Strategy/BBOX.js

@@ -157,13 +157,9 @@ OpenLayers.Strategy.BBOX = OpenLayers.Class(OpenLayers.Strategy, {
      *      returned by the layer protocol.
      */
     triggerRead: function() {
-        var filter = this.createFilter();
-        if (this.response && this.response.priv &&
-            typeof this.response.priv.abort == "function") {
-            this.response.priv.abort();
-        }
+        this.layer.protocol.abort(this.response);
         this.response = this.layer.protocol.read({
-            filter: filter,
+            filter: this.createFilter(),
             callback: this.merge,
             scope: this
         });