Listening when new records are added to the store via a computer property

问题

I am pushing records into my store using websockets.

I am displaying items on the screen via a handlebars template

{{#each item in items}}
  <div>{{item.name}}</div>
{{/each}}

In my controller I have the items collection

items : function() {
   var items = this.store.find('items');
   return items.filterBy({type : "NEW"});
}.property()

Now, when new records are added to the store, I need to update the items automatically.

items : function() {
   var items = this.store.find('items');
   return items.filterBy({type : "NEW"});
}.property('??????')

So is there some way of listening to the store when records are added via a computed property. Ideally I would like to listen to models of a particular type.

回答1:

The best way to do this is to do:

items : function() {
  return this.store.filter(function(item){
      return item.get('TYPE') === 'NEW';
  });
}.property()

store.filter returns a live array that updates whenever there are any changes in the store, so it will respond to the new records beings pushed.

回答2:

Im assuming you are using an array controller. You just need to observe the content array like content.[]. So your controller code should look like

App.IndexController = Em.ArrayController.extend({
  filteredContent: function() {
    return this.get('model').filterBy('type', 0);
  }.property('model.[]')
});

And use the filteredContent in the template

{{#each filteredContent}}
  <li>{{title}} - {{songCount}}</li>
{{/each}}

Here is a working bin.

来源：https://stackoverflow.com/questions/25324121/listening-when-new-records-are-added-to-the-store-via-a-computer-property