BackboneJS: this.$el undefined on other key value function (Backbone.View)

Question

I have a code like this in JavaScript:

var addModalView = Backbone.View.extend({
      tagName:"div",
      el:$("#addemployee"),
      showbutton:$("#addemployee_button"),
      showbutton_click:function(e) {
          this.$el.modal("show"); // this.$el is undefined and not working
      },
      initialize:function() {
        this.showbutton.on("click", this.showbutton_click);
        this.$el.modal("show"); // this.$el is defined and working
      }
  });
myaddModalView = new addModalView();

Why is this.$el defined and working on initialize but not on other key index ( showbutton_click )?

Answer 1

The proper implementation should be like this using the events hash.

var addModalView = Backbone.View.extend({
  el: $("#addemployee"), // should be avoided if possible
  events: {
    'click #addemployee_button': 'showbutton_click'
  },
  initialize: function() {
    this.$el.modal("show");
  },
  showbutton_click: function(e) {
    this.$el.modal("show");
  },
});

myaddModalView = new addModalView();

If for some reason #addemployee_button is not inside "#addemployee" , then the event binding should happen in whichever view actually contains it.

Answer 2

I already solved the problem all i need is to bind the backbone object on initialize.

var addModalView = Backbone.View.extend({
      tagName:"div",
      el:$("#addemployee"),
      showbutton:$("#addemployee_button"),
      showbutton_click:function(e) {
          this.$el.modal("show"); // this.$el is now defined and working
      },
      initialize:function() {
        this.showbutton.on("click", this.showbutton_click);
        _.bindAll(this, "showbutton_click"); // bind it first on showbutton_click
        this.$el.modal("show"); // this.$el is defined and working
      }
  });
myaddModalView = new addModalView();

This bind code is the solution and should be added on initialize : _.bindAll(this, "showbutton_click"); so you can call the backbone object inside your custom function variables using the this keyword.