how to do polling in backbone.js?

Question

Hi i am working on a paly2.0 framework application(with java) using backbone.js. In my application i need to get the table data from the database regularly ( for the use case of displaying the upcoming events list and if the crossed the old event should be removed from the list ).I am getting the data to display ,but the issue is to hit the Database regularly.For that i tried use backbone.js polling concept as per these links Polling a Collection with Backbone.js , http://kilon.org/blog/2012/02/backbone-poller/ .But they not polling the latest collection from db. Kindly suggest me how to achieve that or any other alternatives ? Thanks in adv.

Answer 1

There is not a native way to do it with Backbone. But you could implement long polling requests adding some methods to your collection:

// MyCollection
var MyCollection = Backbone.Collection.extend({
  urlRoot: 'backendUrl',

  longPolling : false,
  intervalMinutes : 2,
  initialize : function(){
    _.bindAll(this);
  },
  startLongPolling : function(intervalMinutes){
    this.longPolling = true;
    if( intervalMinutes ){
      this.intervalMinutes = intervalMinutes;
    }
    this.executeLongPolling();
  },
  stopLongPolling : function(){
    this.longPolling = false;
  },
  executeLongPolling : function(){
    this.fetch({success : this.onFetch});
  },
  onFetch : function () {
    if( this.longPolling ){
      setTimeout(this.executeLongPolling, 1000 * 60 * this.intervalMinutes); // in order to update the view each N minutes
    }
  }
});

var collection = new MyCollection();
collection.startLongPolling();
collection.on('reset', function(){ console.log('Collection fetched'); });