Override ArrayReader's readRecords() method to convert data from server

Hi
ExtJS 3.4.0
I need to convert data to a different format and I'm attempting to do this by overriding the readRecords() method.
So far this code gives an error after the 'readRecords:' console message.
Any help or suggestions or links to samples would be appreciated.

Code:

---

readRecords:
TypeError: b is undefined

---

Code:

---

    var MyFields = Ext.data.Record.create([
        {name: 'id'},
        {name: 'name'}
    ]);

    MyReader = Ext.extend(Ext.data.ArrayReader, {
        fields: MyFields,

        readRecords: function(o) {
            console.log('readRecords:');
            MyReader.superclass.readRecords.apply(this, o);
        }

    });

    MyStore = Ext.extend(Ext.data.ArrayStore, {
        reader: new MyReader()
    });

---

So this field in the reader can convert the value you are parsing to the one you want. Here you can see that i get from server only a string "false" or "true" and with this function i change it for a boolean true or false. I hope it helps ? http://www.sencha.com/forum/images/smilies/6.gif

PHP Code:

---

 {
                   name: 'released',
                   mapping: 'realeased',
                   convert:  function(v, r){
                    var ret = false;
                    if (v == "true") {
                        ret = true;
                    }
                    return ret;
                }
                   } 


---

This thread describes what I need to do, but in Sencha Architect.

HOWTO - reformat data sent from server at the Store
http://www.sencha.com/forum/showthread.php?243849

I need to do the same thing in ExtJS 3.4.0
Any help/suggestions would be greatly appreciated.