Backbone.js - change not triggering while the name

问题:

In my backbone function, while the name get change the change function not at all triggering.. any one suggest me the right way to get it.. (actually i need to get changed stuff and need to update);

code :

    (function($){

var list = {};

list.model = Backbone.Model.extend({
  defaults:{
    name:'need the name'
  },
  initialize:function(){
    this.bind('change:name', function(model) {
        console.log('Model->change()', model);
    });
  }
});

list.collect = Backbone.Collection.extend({
  model:list.model,
  url : 'data/names.json',
  initialize:function(){
    this.fetch({update:true});
    this.keepUpdate();
  },
  keepUpdate:function(){
    var that = this;
    var updateData = function(){
      that.fetch({update:true});
      myTimeout = setTimeout(updateData,10000);
    }
    var myTimeout = setTimeout(updateData,10000);
  }
});


list.view = Backbone.View.extend({
  initialize:function(){
    this.collection = new list.collect();
    this.collection.on("update", this.render, this);
    this.collection.bind("change:name", function(model, attributes){
      console.log(model,attributes,'property changed'); // this is not triggering at all..
    });
  },
  render:function(data){
    _.each(this.collection.models, function(data){
      //console.log(data.get('name')); it works fine
    })
  },
  updateName:function(){
    console.log('updated called');
  }
});

var newView = new list.view();    

})(jQuery)

回答1:

Collection.fetch doesn't trigger the change event. You only get the reset event. If you need more granular events, consider calling fetch with the options {update:true}.

that.fetch({update:true});

That will trigger change event for every model that was already in the collection, and add if the model was previously not in the collection.

回答2:

Try removing keepUpdate from the collection and put a setTimeout in the initialize function of the view at the end. I suggest that fetch is called from the view as well as this.collection.fetch() instead of the collection's initialize function. Makes your code more reusable.

回答3:

I'm not sure I understand your question. What are you trying to achieve ?

I don't think that fetch accepts {add:true} as a parameter (I just checked the source code and it does not appear anywhere).

When fetch completes, it only triggers a reset event (not an add). You should listen to that if you want to do something when the content of the collection changes. You can also simplify listen to change.