backbone.js - Reference to HTML elements in view, a convention? -


i'm in progress of learning backbone.js , i'm using book developping backbone applications.

i have questions reference html elements , how stored. example: 

   initialize: function() {         this.$input = this.$('#new-todo');

here html element id to-do stored in this.$input, why use $ in front of input, merely convention? if change this.$input this.input code works fine. find confusing because book states:

the view.$el property equivalent $(view.el) , view.$(selector) equivalent $(view.el).find(selector).

i think $(view.el) different (view.el).

how this.$input saved in backbone.js? if console.log it, produces: 

object[input#new-todo property value = "" attribute value = "null"]

could give me insight? :)

  • using $ infront of variable name naming convention. helps developer in distinguishing variable holding jquery objects others.

  • view.$el helper variable provided backbone, can use directly, instead of explicitly forming jquery object. hence view.$el equivalent $(view.el).

view.$el assigned in setelement method:

setelement: function(element, delegate) {    // code    this.$el = element instanceof backbone.$ ? element : backbone.$(element);    // code }

backbone.$ reference $ global variable exported jquery.

  • view.$(selector) method defined in view. it's definition same $(view.el).find(selector)

    $: function(selector) { return this.$el.find(selector); }


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