I\'m using PHP, ExtJS and ajax store.
It sends data (on create, update, destroy) not in POST or GET. In the
Also you can setup extJs writer with encode: true and it will send data regularly (and, hence, you will be able to retrieve data via $_POST and $_GET).
... the values will be sent as part of the request parameters as opposed to a raw post (via docs for encode config of Ext.data.writer.Json)
UPDATE
Also docs say that:
The encode option should only be set to true when a root is defined
So, probably, writer's root config is required.