I've been happily using jQuery, creating vars and binding events in my modules (which have only a little bit of JS). But recently I needed to add an anonymous functions to my code and after investigating some more, I learned about modular patterns and encapsulation.

So what I'm trying to teach myself is to write clean, fast and maintainable JavaScript code in object-oriented fashion (as opposed to "functional" jQuery code before).

My module inserts a search box (input) that uses Ajax and displays drop-down results.

What I want to have is a template file with the search box other necessary elements; Then the most flexible way would be to pass the elements to the code in JavaScript file - I could easily adjust settings in the same file if I decide to change IDs or the elements.

Then there should be a separate file with the actual code; It should make no presumptions about the elements of the page.

I follow this article:


These are my thoughts and what I would like to know:

  • Is this structure written correctly to accomplishing this task?
  • Is the anonymous function (self-executing one) being used correctly here?
  • Is there anything to be optimized (maybe I'm "overkilling" something)?
  • Is $.proxy used correctly?
  • I to use an object to defined methods, however, I cant think of a way to only expose a public method. Is writing non-objective (simple enclosed vars and functions) the way to go?


<script type="text/javascript" src="autosearch.js"></script>

    <input id="search-1" type="search">

<script type="text/javascript">
        input  : $('#search-1'),
        option2: ''


var AutoSearch = (function($) {

    var search = {

        cache: {},
        bindEvents: function(){
           this.input.on('keyup', $.proxy(this.processInput, this));
        processInput: function(){ alert(this.input.val()); },

        init: function(options) {
            this.input = options.input;


    return search;

  • \$\begingroup\$ I fixed it up a little bit. It has all the relevant parts. Mostly I'm interested in the layout and structure. \$\endgroup\$
    – gskema
    Dec 18, 2014 at 21:46

1 Answer 1


Your mistake is in your processInput() function, it is not created as part of the search object and is invalid syntax the way you have it written.

I try to avoid private functions in javascript as it makes them difficult to test, but if you really wanted to have private functions, you could write your module like this:

var AutoSearch = (function () {
    "use strict";

    // private
    var my = {},

    // private
    function processInput() {

    // private
    function bindEvents() {
        input.on('keyup', processInput());

    // public
    my.init = function (options) {
        input = options.input;

    return my;

It's not obvious to me that you need jQuery or .proxy() at this point, since all the data and functions for the event handler are inside the closure.

  • \$\begingroup\$ The mistake was just a typo. I followed this example esbueno.noahstokes.com/post/77292606977/… \$\endgroup\$
    – gskema
    Dec 19, 2014 at 6:38
  • \$\begingroup\$ That's a good example. Looks like they decided not to hide the functions, which is what I usually prefer. However I feel that avoiding using this (as in my example) makes the code easier to read/understand. \$\endgroup\$
    – mikhail
    Dec 19, 2014 at 18:15

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