Backbone.js: Elegant way to check if data ready and if the dataset is empty

Question

I\'m looking for a better solution for two things:

• How can I understand if the data is fetched and ready, I use BasicDealList.on(\"reset\", function()

Answer 1

I know this question has already been answered but here is an alternative.

BasicDealCollection = Backbone.Collection.extend({
    model: BasicDeal,
    url: '/some/ajax/url/',
});

myCollection = new BasicDealCollection()
deferred = myCollection.fetch()

$.when(deferred).then(function() {
  // do stuff when we have the data.
});

The key benefit of this is that we are using the "when" function. The "when" function gives us the ability to check multiple fetch calls and do one success.

$.when(deferredOne, deferredTwo, deferredThree).then(function() {
  // do stuff when we have the data.
});

Also, if we stored the deferred object into a variable, we can do things like this. The variable will be a flag to let us know that we already loaded the data.

if (deferred.state() === "resolved") {
    // do stuff when we have the data.
}

When we call fetch() on a collection it returns a jQuery deferred object. A jQuery deferred object can be in 3 states, "pending", "rejected" or "resolved" and once we have the data, it will set the state of the deferred object to resolved.