Skip to main content

Javascript Module Pattern

Module pattern is one of the well know design patterns in JavaScript. I did read about this pattern, for the first time, in a publication done by Douglas Crockford. Since then, I have used this pattern in many occasions in my coding.

Using a module, an interface can be presented, by hiding the implementation and the state of an object. And it's a way of having private attributes and methods. A simple implementation is given below.


var containers = (function () {

        var module = {};
    
        var default_container_width = 500; //private property

        var possible_containers_list = new Array();
        possible_containers_list[1]="comments";
        possible_containers_list[2]="respond";   

        module.list = possible_containers_list; //public property

        function getContainerWidth() {//private function
            // ...
        }

        module.hideAll = function () {//public function
           // ...
        };

        return module ;
}());


To call the public functions and to get the public property values:

containers.hideAll();
var list = containers.list;

With this pattern, the use of global variables can also be reduced.

Comments

Popular posts from this blog

Common Characteristics of Enterprise Applications

Last week, I was conducting a tech talk about “Architectural Patterns of Enterprise Applications” with our team. The discussion was mainly based on Marin Fowler's famous book “Patterns of Enterprise Application Architecture”. So, I thought, it's good to write something about that in my Blog. Given below are few common characteristics of Enterprise Applications. If any software product has the following characteristics, we can identify it as an Enterprise Application. These ware originally documented by “Martin Fowler”, in his book “Patterns of Enterprise Application Architecture”. Persistent Data - Enterprise applications usually involve persistent data. The data is persistent because it needs to be around between multiple runs of the program—indeed, it usually needs to persist for several years. Also during this time there will be many changes in the programs that use it. Lot of Data - There's usually a lot of data, a moderate system will have over 1 GB of data organ

How to avoid those little issues one can get when creating new projects with Zend Framwork...

CSS styles my not apply to the templates : Some times this happens when you haven't created a virtual host for the application. After the virtual host is created styles will apply properly, or just use some url helper like "baseUrl" when linking the style sheets to the templates. Error messages when using the commands like "zf enable layout", "zf create db-table ....", "zf create model ...", "zf configure db-adapter", and "zf create action ...." etc... You may get error like "Action 'enable' is not a valid action", "Action 'configure' is not a valid action"......... etc... Reason for this may be, the Zend library is not in the include path. If so add the library path to the include path. Or check whether there are old libraries in any directories of include paths that conflicts with the new one. Check whether there is a one as a PEAR package. And check whether the "zf" c

How to create a waveform animation with HTML and JavaScript

Recently, for a pet project, I wanted to create an animation of a waveform based on the varying decibel level of the microphone input. I was thinking about a really simple way to accomplish this with SVG and JavaScript. Given below is the first sample code I did on the Codepen. You can change this code to use with any framework of your choice. For this sample code, I am using a random number as the microphone input. You can replace it with any other time based input. Code Pen : https://codepen.io/nadeeth/pen/vmaYXw For this example, you need an HTML code snippet like the one given below. It’s just an SVG with a Polyline element inside.  <div style="text-align:center">   <svg height="150" width="400" id='svg'>     <polyline id="polyline-id" fill="none" stroke="#005c66" stroke-width="1" />   </svg> </div> And then the plain Javascript code to animate the polyline. You can