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


  1. Can I simply say what a relief to uncover somebody who truly understands what they are discussing on the web. You definitely realize how to bring a problem to light and make it important. More and more people have to check this out and understand this side of the story. I was surprised you're not more popular since you surely have the gift. facebook login in

    ReplyDelete
  2. This is the first & best article to make me satisfied by presenting good content. I feel so happy and delighted.By Learn Digital Marketing Course Training in Chennai it will help to get Digital Marketing Course Training with Placement Institute in Chennai. If you Learn Social Media Marketing Training with Placement Institute in Chennai, you will get job soon.

    Learn Best Digital Marketing Course Training in Chennai in professional institute to get reputed job.

    ReplyDelete

Post a Comment

Popular posts from this blog

How to create a new module for vtiger...

Recently, I had to create a new module for vtigerCRM for my client in current working place. I did search in many places including the official vtiger sites, but couldn’t find a better documentation for my purpose. The latest vtiger version at that time was 5.0.3. Because I had some experience doing lots of core modifications for this system, I did decide to read the source code and find how to add a new module. Finally, I could create a new module and started the project. So, I thought it will be a good thing to write some thing on my blog about this topic, so that others who want to do this thing can read. Given below is a brief description about how to create a new module for vtiger CRM 5.0.3. Source code of this example module is also available to Download.
Step 01: Creating the module directory and minimum required files.
Create a directory called “newModule” inside your vtiger modules directory, or any other name that you prefer. Now, module index file should be created. Create a…

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 organized in…

De Morgan's Laws in Programming

Recently, while I was reviewing some codes, I saw there were some conditional statements that check for the same condition but written in different ways. Most of these statements were written with common sense without using any mathematical analysis, since those are too simple to go for a more formal approach. The two identical conditional statements that has been written in different ways are given below.

01)

if ($comment['deleted'] == '1' || $comment['approved'] == '0') {
                unset($conversationsArray[$key]);
} else {
               ++$count;
}

02)

if ($comment['deleted'] == '0' && $comment['approved'] == '1') {
               ++$count;             
} else {
             unset($conversationsArray[$key]);
}

Obviously, the above lines say that the inverse of the first condition is equals to the second condition and vice versa. That is...

 ($comment['deleted'] == '1' || $comment['ap…