Contetns jQuery widget

$(function(){

    $.widget('custom.contents', {

        /**
         * Default widget options
         */
        options : {

            element     : 'h2',                 // The elements that are to be listed in the contents

            showTitle   : true,                 // Whether or not to show a title above the contents
            titleWrap   : 'h2',                 // The HTML element to wrap the title in
            titleID     : 'contents-title',     // The ID to add to the title element
            titleClass  : '',                   // The classes to add to the title element
            titleText   : 'Contents',           // The text to display above the contents

            singleWrap  : 'a',                  // The HTML element to wrap each contents line with
            singleID    : 'content-{index}',    // The ID to add to each contents line
            singleClass : 'content',            // The class to add to each contents line

            linkID      : 'link_to_{singleID}'  // The ID to use for linking contents to the main document

        }, // options

        /**
         * Constructor
         */
        _create : function(){

            this.elements = this._getElemets();     // Grab the elements
            this.linkSingles = this._linkSingles(); // Check whether or not single

            this._doTitle();    // (Maybe) output the title
            this._doContents(); // Output the contents

        }, // _create

        /**
         * Return an object containing all of the requested elements
         *
         * @return jQuery
         */
        _getElemets : function(){

            return $(this.options.element);

        }, // _getQuestions

        /**
         * Whether or not to add a link to each element
         *
         * @return boolean
         */
        _linkSingles : function(){

            return (this.options.singleWrap == 'a');

        }, // _linkSingles

        /**
         * (Maybe) output the contents title
         */
        _doTitle : function(){

            if(!this.options.showTitle || this.elements.length <= 0)    // Ensure the title should be shown
                return false;

            var title = $('<' + this.options.titleWrap + '>')   // Create the title element...
                .attr('id', this.options.titleID)               // ...Add the 'ID' attribute
                .addClass(this.options.titleClass)              // ...Add the 'class' attribute
                .text(this.options.titleText);                  // ...Add the title text

            this.element.append(title); // Append the title to the element upon which this widget was instantiated

        }, // _doTitle

        /**
         * Output the contents
         */
        _doContents : function(){

            var t = this;   // This object

            this.elements.each(function(index){ // Loop through each element that is to be added to the contents...

                var trueIndex = index + 1,          // ...Start indexing at 1, not 0
                    line = t._getSingle(trueIndex); // ...Construct the contnets line

                if(t.linkSingles){                                              // Check whether or not the contetns should be links
                    line.attr('href', '#' + t._getOption(trueIndex, 'linkID')); // ...Insert the 'href' element in to the contents line
                    $(this).attr('id', t._getOption(trueIndex, 'linkID'));      // ...Insert the 'name' attribute in to the targeted element
                }

                line.text($(this).text());      // ...Add the relevant text to the contents line
                t.element.append(line);         // ...Insert the contents line

            });

        }, // _doContents

        /**
         * Return a single contents line as an object
         *
         * @param required integer index    The index of the current contents line
         * @return jQuery
         */
        _getSingle : function(index){

            var line = $('<' + this.options.singleWrap + '>')
                .attr('id', this._getOption(index, 'singleID'))
                .addClass(this.options.singleClass);

            return line;

        }, // _getContnetsLine

        /**
         * Get the extracted value of a given option
         *
         * @param required integer index    The index of the current contents line
         * @param required string option    The option to get the value of
         * @return string ID
         */
        _getOption : function(index, option){

            var t = this;   // The object

            var optionValue = this.options[option].replace(/{(.+?)}/g, function(_, name){   // Search for all instances of '{(.+?)}'...
                return name === 'index' ? index : t.options[name];                          // ...Replace all instance of '{(.+?)}' with the value of the associated variable
            });

            return optionValue;

        } // _getOption

    });

});