The Activity Stream View in Backbone

activity_stream_view.js

var ActivityStreamView = Backbone.View.extend({
    el: '#main_stream', // el attaches to existing element

    initialize: function(){
        _.bindAll(this, 'render', 'appendItem'); // every function that uses 'this' as the current object should be in here
        this.collection = new ActivityList();
        this.collection.bind('add', this.appendItem); // collection event binder
        this.maxSize = 20;
    },
    render: function(){
        _(this.collection.models).each(function(item){ // in case collection is not empty
            self.appendItem(item);
        }, this);
    },

    appendItem: function(item){
      var itemView = new ActivityView({ model: item });

      this.$el.prepend(itemView.render().el);

      if (this.el.children.count > this.maxSize) {
          this.el.children.last.remove();
      }
    }
});