Taking brackets out of the callback.

The Yahoo API doesn't accept quotes in the callback (e.g. foo['bar']).  Since the callback registry is an object and all identifiers are prefixed with "c" now, we can use dot notation.

lib/OpenLayers/Protocol/Script.js

@@ -56,10 +56,11 @@ OpenLayers.Protocol.Script = OpenLayers.Class(OpenLayers.Protocol, {
     /**
      * APIProperty: callbackTemplate
      * {String} Template for creating a unique callback function name
-     * for the registry. Should include ${id}.
-     * Default is "OpenLayers.Protocol.Script.registry['${id}']".
+     * for the registry. Should include ${id}.  The ${id} variable will be
+     * replaced with a string identifier prefixed with a "c" (e.g. c1, c2).
+     * Default is "OpenLayers.Protocol.Script.registry.${id}".
      */
-    callbackTemplate: "OpenLayers.Protocol.Script.registry['${id}']",
+    callbackTemplate: "OpenLayers.Protocol.Script.registry.${id}",
 
     /**
      * APIProperty: callbackKey

tests/Protocol/Script.html

@@ -135,7 +135,7 @@
     }
 
     function test_createRequest(t) {
-        t.plan(5);
+        t.plan(6);
         var protocol = new OpenLayers.Protocol.Script({
             callbackKey: 'cb_key',
             callbackPrefix: 'cb_prefix:'
@@ -153,15 +153,17 @@
 
         var params = OpenLayers.Util.getParameters(script.src);        
         t.eq(params.k, "bar_param", "custom query string param");
-        t.eq(params.cb_key, "cb_prefix:OpenLayers.Protocol.Script.registry['bar']", "callback with prefix");
+        t.eq(params.cb_key, "cb_prefix:OpenLayers.Protocol.Script.registry.bar", "callback with prefix");
 
         t.eq(script.id, 'OpenLayers_Protocol_Script_bar',
             'created script has a correct id');
 
-        protocol.callbackTemplate = "OpenLayers.Protocol.Script.registry.${id}";
-        script = protocol.createRequest('http://bar_url/', {'k': 'bar_param'}, 'bar_callback');
-        t.eq(script.src, 'http://bar_url/?k=bar_param&cb_key=cb_prefix%3AOpenLayers.Protocol.Script.registry.bar',
-            'created script has a correct url with different template');
+        protocol.callbackTemplate = "customCallback(${id})";
+        script = protocol.createRequest('http://bar_url/', {'k': 'bar_param2'}, 'bar_callback');
+
+        params = OpenLayers.Util.getParameters(script.src);        
+        t.eq(params.k, "bar_param2", "custom query string param");
+        t.eq(params.cb_key, "cb_prefix:customCallback(bar)", "custom callback with prefix");
 
         OpenLayers.Protocol.Script.register = _register;