Backbone base64 encoding - backbone.js

Question

I don't get how to make Backbone.sync suitable for my case.
That's why I still use this usual Ajax-Request for my project:
$.ajax({
url: request,
status: status,
type: 'GET',
dataType: 'json',
beforeSend: function (req) { req.setRequestHeader("Authorization", auth) },
success: function (data, status) {
//update the model
},
error: function(XMLHttpRequest, textStatus, errorThrown){
//do stuff
}
});
I need to add a base64 encoded authorization to the request header and update a model. The data I get from the server contain more information than my model needs. That's why I can't refer the model directly to an url like this:
var MyApp.myModel = Backbone.Model.extend({
url: '/someResourceUrl'
});
MyApp.myModel.fetch();
I need to do sth. like:
var MyApp.myModel = Backbone.Model.extend({
url: 'anyurl',
sync: myOwnSpecificSync,
});
//Define the sync function:
myOwnSpecificSync = function(method, model, options) {
//add header
//return only specific parameters of the success data
};
//let the model fetch the data from the server
MyApp.myModel.fetch();
But I have no idea how to implement the functions .. or if it's correct at all.

Answer 1

var AuthSync = function(method, model, options) {
options.beforeSend = function () {
console.log('add auth header here');
};
return Backbone.sync(method, model, options);
};
var Model = Backbone.Model.extend({
url : 'http://fiddle.jshell.net/echo/json/',
sync : AuthSync
});
new Model().fetch();