Javascript 自执行匿名函数的唯一实例

Question

I have created the PHP side of a modular AJAX/PHP framework and now I am trying to implement the client side.

From my previous experience with modular web applications I know that sometimes multiple instances of one particular module are needed. For example, a web based two player game with page parts for each user.

On PHP side I have assigned a unque ID to each constructed instance of the module and I can pass this UID to the browser but I have no idea how to implement the Javascript side of this module instance.

Modules can be loaded all in one go or loaded separately through AJAX (I am using jQuery).

Now I am using a modular approach that I found in some article, but I can redesign it in some other way if that would help to solve this issue without sacrifising modularity and private/public code separation. For now let's say I have a js file with the following:

//Self-Executing Anonymous Func
(function( MyModule, $, undefined ) {

    // My Uid
    MyModule.UID = "";

    //Public Method
    MyModule.onLoad = function() {
       alert("Hey, you loaded an instance of MyModule with UID " + MyModule.UID);      
    };

    //Private Methods follow
    function somethingPrivate( ) {

    }    
}( window.MyModule = window.MyModule|| {}, jQuery ));

I am using Smarty for templates. Let's say, I have a simple module template like this:

<div id="{$contents.moduleuid}">
here goes the contents of the module which can be accessed from MyModule Javascript code by using this unique moduleuid
</div>

I have set up the server side so each module automatically appends additional template with Javascript:

    <script type="text/javascript">
    /*
    TODO: here I have access to the {$contents.moduleuid} 
    But I have no idea what to put here to create a unique instance of MyModule
 (also it might need loading js file if it was not loaded yet) and I should also set for
 this instance MyModule.UID to {$contents.moduleuid} 
and also call MyModule.onLoad for this instance after it has loaded its Javascript.  
    */
    </script>

I am not experienced with advanced Javascript topics so it is unclear to me how I can create a separate instance of MyModule for each module which gets construced server-side? Is it possible at all to create instances of self-executing anonymous functions? If not, then how can I implement and clone Javascript objects with separated private/public code?

Answer 1

My recommendation is to keep the client side and server side loosely coupled. Try to build your modular client application completely with HTML/JS without PHP tricks on it. As I understand, each of your module (or UI component) need to be loosely coupled from the others. In such case there are several other concerns you might need to look for:

• How to keep your UI component structure (html), presentation (css) and behavior (JS) self contained (for example in a single folder), so that it can live or die independently
• How these self contained components interact with each other
• How to manage the configurations/settings of your UI components
• Should you be using MVVM or MVC pattern to organize and bind the view to your PHP model
• Who decides when to create/show/hide your UI components (for example based on URL for bookmarking)

If your client is a large and complex application, you might need to look for other concerns such as JS optimization, unit testing, documentation, product sub modules, etc.

Have a look at the BoilerplateJS Javascript reference architecture we put forward at http://boilerplatejs.org . It suggests ways to address all concerns I discussed above.

Answer 2

Since you are already using jQuery, you could create a jQuery plugin. The plugin should behave the way you need, and I believe you won't even need a unique ID. Considering each of your module's instance is contained in a div with class module-container , your jQuery code for adding client-side behavior to the divs would be something like this:

$(function(){
    // DOM content is loaded
    $('.module-container').MyPluginName();
});

The minimal plugin code would be (considering it's in a separate.js file):

(function($){
  $.fn.MyPluginName = function() {  
     // Return this.each to maintain chainability
    return this.each(function() {
      // Keep a reference to your unique div instance.
      var $this = $(this);
      // Plugin logic here
    });
  };
})(jQuery);

If you are using jQueryUI, I also recommend you also look into the "widget factory" ( intro , docs ), which serves as a base for building powerful, normalized jQuery plugins.