How can I set global http headers for ajax requests?

[semanticart]

I want to send the device ID in every request to my server. What's the easiest way to globally set headers without regard to what store is being used (inline or a defined class)?

I came up with this, which works but feels rather hacky:

Ext.override(Ext.data.proxy.Ajax, {
  constructor: function(config) {
    config.headers || (config.headers = {});
    config.headers.uuid = 'SOME-EXAMPLE-UUID';
    return this.callOverridden([config]);
  }
});

I'm new to Sencha Touch, so any help is appreciated.

[mitchellsimoens]

http://docs.sencha.com/touch/2-0/#!/...-beforerequest

[semanticart]

Thanks, I ended up doing this:

Ext.Ajax.on('beforerequest', (function(klass, request) {  return request.headers.uuid = 'SOME-EXAMPLE-UUID';
}), this);

Obviously I'll be using a function instead of hard-coding the uuid. Thanks again for the help, let me know if there's yet a better way.

[shri_iitk]

This is what I use:

Ext.Ajax._defaultHeaders = {
            'token' : (loggedInUserToken == undefined) ? "" : loggedInUserToken,
            'Accept': 'application/json',
            'Authorization': 'Basic YX5iOmM='
        };

[shepsii]

I prefer semanticart's way as it's always best to avoid modifying private variables. The former way should be more future-proof.