a template for creating jQuery plugins

jquery.plugin-template.js

// remember to change every instance of "pluginName" to the name of your plugin!
(function($) {
    // here it goes!
    $.fn.pluginName = function(method) {
        // plugin's default options
        var defaults = {
            foo: 'bar'
        };
        // this will hold the merged default and user-provided properties
        // you will have to access the plugin's properties through this object!
        // settings.propertyName
        var settings = {};
        // public methods
        // to keep the $.fn namespace uncluttered, collect all of the plugin's methods in an object literal and call
        // them by passing the string name of the method to the plugin
        //
        // public methods can be called as
        // $(selector).pluginName('methodName', arg1, arg2, ... argn)
        // where "pluginName" is the name of your plugin and "methodName" is the name of a function available in
        // the "methods" object below; arg1 ... argn are arguments to be passed to the method
        //
        // or, from within the plugin itself, as
        // methods.methodName(arg1, arg2, ... argn)
        // where "methodName" is the name of a function available in the "methods" object below
        var methods = {
            // this the constructor method that gets called when the object is created
            init : function(options) {
                // the plugin's final properties are the merged default and user-provided properties (if any)
                // this has the advantage of not polluting the defaults, making the same instace re-usable with
                // new options; thanks to Steven Black for suggesting this
                settings = $.extend({}, defaults, options);
                // iterate through all the DOM elements we are attaching the plugin to
                return this.each(function() {
                    // "$el" holds the jQuery version of the current DOM element
                    // "this" refers to the actual DOM element
                    var $el = $(this);
                    // code goes here
                });
            },
            // a public method. for demonstration purposes only - remove it!
            foo_public_method: function() {
                // code goes here
            }

        };
        // private methods
        // these methods can be called only from within the plugin
        //
        // private methods can be called as
        // helpers.methodName(arg1, arg2, ... argn)
        // where "methodName" is the name of a function available in the "helpers" object below; arg1 ... argn are
        // arguments to be passed to the method
        var helpers = {
            // a private method. for demonstration purposes only - remove it!
            foo_private_method: function() {
                // code goes here
            }
        };
        // if a method as the given argument exists
        if (methods[method]) {
            // call the respective method
            return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
        // if an object is given as method OR nothing is given as argument
        } else if (typeof method === 'object' || !method) {
            // call the initialization method
            return methods.init.apply(this, arguments);
        // otherwise
        } else {
            // trigger an error
            $.error( 'Method "' +  method + '" does not exist in pluginName plugin!');
        }
    };
})(jQuery);