How to synchronize multiple Backbone.js fetches?

Question

I’m a bit new to Backbone.js, but am already impressed by everything it can do for me, and am trying to learn the patterns and best practices now.

I have two collect

Answer 1

As @JayC said you could use $.when from jQuery, other option that I prefer is the after function (from Underscore), which execute one time just after expected calls are completed.

http://underscorejs.org/#after

function runMyApp(){
  // run the needed code here.
  console.log('This will run one time but until both fetch are being completed.');
}

//2 because you have two collections
var renderApp = _.after(2, runMyApp);
collA.fetch({success: renderApp});
collB.fetch({success: renderApp});