Module Pattern

Published 4 years ago.
Last updated October 3rd, 2018

// Standard module pattern enclosure.
var module = (function(){
    /* module code */
}());

// jQuery module pattern enclosure.
var module = (function($){
    /* module code */
})(jQuery);

See a demo on codepen.io

// jQuery Module definition.
var module = (function($){

    // Private variable.
    var privateValue = 0;

    // Public functions.
    function getValue()
    {
        return privateValue;
    }

    function setValue( value )
    {
        privateValue = value;
    }

    function incrementValue()
    {
        privateValue++;
    }
    
    // Return public functions.
    return {
        getValue: getValue,
        setValue: setValue,
        incrementValue: incrementValue
    }

})(jQuery);

jQuery( document ).ready(function() {
    // Use the module.
    console.log( module.getValue() );          // Returns: 0
    module.setValue( 5 );                      // Set the value to 5
    console.log( module.getValue() );          // Returns: 5
    module.incrementValue();                   // Increment the number
    console.log( module.getValue() );          // Returns: 6
});

This pattern is a way of creating a self-contained module or library that can be accessed by other scripts.

When JavaScript executes, the module is immediately bound to a variable. This is done by wrapping the content of the module in a self-executing function which returns the module’s public functions to the variable. The module’s public functions and properties can then be accessed from the variable using the . (dot notation property accessor) like so: module.myFunction();.