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Based on the official documentation, when I do something like this:
collection.fetch({update: true, remove: false})
I get an "add" event for every new model, and a "change" event for every changed existing model, without removing anything.
Why if I'm calling an static source of data (the url of the collection always return the same json) an add event is called for each item received?
Here some code (I'm not rendering anything, I'm just debugging):
<!doctype html>
<html>
<head>
<title>Example</title>
</head>
<body>
<a href="#refresh">Refresh</a>
<script src="js/jquery-1.8.3.min.js"></script>
<script src="js/underscore-min.js"></script>
<script src="js/backbone-min.js"></script>
<script src="js/main.js"></script>
</body>
</html>
Heres the JS
(function($){
//Twitter Model
ModelsTwitt = Backbone.Model.extend({});
//Twitter Collection
CollectionsTwitts = Backbone.Collection.extend({
model:ModelsTwitt,
initialize:function(){
console.log('Twitter App Started');
},
url:'data/195.json'
});
//Twitts View
ViewsTwitts = Backbone.View.extend({
el:$('#twitter-list'),
initialize:function(){
_.bindAll(this, 'render');
this.collection.bind('reset',this.render);
this.collection.bind('add',this.add);
},
render:function(){
console.log("This is the collection",this.collection);
},
add:function(model){
console.log("add event called",model);
}
});
//Twitter Router
Router = Backbone.Router.extend({
routes:{
'':'defaultRoute',//Default list twitts route
'refresh':'refreshView'
},
defaultRoute:function(){
this.twitts = new CollectionsTwitts();
new ViewsTwitts({collection:this.twitts});
this.twitts.fetch();
},
refreshView:function(){
this.twitts.fetch({update:true,remove:false});
}
});
var appRouter = new Router();
Backbone.history.start();
})(jQuery);
Basically, I fetch the collection using the defaultroute, it is fetched properly with all the models and attributes.
And when I click on the refresh link, I call refreshView, which basically tries to update the collection with new models. What I don't understand is why if the response is the same, all the models of the collection are detected as new, triggering an add?
Heres a functional link: open the console and you will see how the add events are called when you click on refresh even when the collection is the same.
Thanks for your help.
355
My guess would be that your models don't have an idAttribute (doc). The default key Backbone looks for is id and your JSON entries don't have one so it can't tell which models are already there.
Try changing your model to this (or another key if this one isn't unique):
ModelsTwitt = Backbone.Model.extend({
idAttribute: 'id_event'
});
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