How can I prevent Ext JS from including an entity body in DELETE requests using a restful store?

Question

When Ext JS issues a DELETE request from a restful store, it includes an entity body. Although this doesn't seem to be forbidden by the HTTP spec, Google App Engine doesn't accept such requests. So I'd like to know if there is a way to prevent a restful store from including a redundant entity body on DELETE requests.

Details:

Using this sample as reference: http://www.sencha.com/deploy/dev/examples/restful/restful.html

This is how the store is defined:

var store = new Ext.data.Store({
    id: 'user',
    restful: true,     // <-- This Store is RESTful
    proxy: proxy,
    reader: reader,
    writer: writer
});

After pressing the "Delete" button, this is the request Ext JS sends:

DELETE http://www.sencha.com/deploy/dev/examples/restful/app.php/users/6 HTTP/1.1
Host: www.sencha.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; pt-BR; rv:1.9.2.4) Gecko/20100611 Firefox/3.6.4 (.NET CLR 3.5.30729)
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: pt-br,pt;q=0.8,en-us;q=0.5,en;q=0.3
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Content-Type: application/json; charset=UTF-8
X-Requested-With: XMLHttpRequest
Referer: http://www.sencha.com/deploy/dev/examples/restful/restful.html
Content-Length: 10
Cookie: bb_sessionhash=8d75f5e42d576fb695a02bf1d24c9ff1; etc...

{"data":6}

When a request in this format (with the "data" content) is submitted to Google App Engine, it replies with:

400 Bad Request

Answer 1

You can fix this problem, as you guessed, by overriding a method in the HttpProxy class. First, add this code:

// Special HttpProxy that sends no body on DELETE requests
Ext.data.GAEHttpProxy = Ext.extend(Ext.data.HttpProxy, {
doRequest: function(action, rs, params, reader, cb, scope, arg) {
    if(this.api[action]['method'].toLowerCase() == "delete") {
        delete params.jsonData;
    }

    Ext.data.GAEHttpProxy.superclass.doRequest.call(this, action, rs, params, reader, cb, scope, arg);
}
});

Then, use this new class ("GAEHttpProxy") instead of HttpProxy in the rest of your code (for instance, when you create the proxy you use in your store shown above). This worked for me, and I hope it works for you!