CODEWITHSUNDEEP
backbone.js
user50992
user50992

Reputation: 201

Backbone reset event in collection

How does Backbone reset event works? As far as I understand

  1. Remove all models from collection
  2. Add newly "fetched" models to collection
  3. Fires reset event

In my case each model draw something on SVG so I should call remove function before removing model from collection. Which event is triggered when model is removed from collection?

Upvotes: 7

Views: 8782

Answers (2)

nikoshr
nikoshr

Reputation: 33344

As @Paul noted, there is no predefined event fired before a reset. However, you can provide your own by overriding the reset method on your collection. For example,

var SVGCollection = Backbone.Collection.extend({
    reset: function(models, options) {
        options = options || {};

        if (!options.silent) {
            this.trigger('prereset', this, options);
        }

        Backbone.Collection.prototype.reset.call(this, models, options);
    }
});

And a sample usage

var c = new SVGCollection([
    {id: 1},
    {id: 2}
]);
c.on('prereset', function() {
    console.log(c.pluck('id'));
});
c.on('reset', function() {
    console.log(c.pluck('id'));
});
c.reset({id: 3});

See http://jsfiddle.net/nikoshr/8vV7Y/ for a demo

You could also trigger events on each model.

Upvotes: 9

Paul
Paul

Reputation: 18597

You're correct that reset is fired after the old models have been removed and the new models have been added.

There isn't an event fired for when a model is removed from a collection through the reset method.

You might have to keep a reference to the old models outside of the collection, and then when the reset event is fired, you will have reference to those models so you can call the remove function for them on SVG.

Upvotes: 3

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