How to develop a jQuery plugin with CoffeeScript

gh-buttons.css

/* ------------------------------------------
CSS3 GITHUB BUTTONS (Nicolas Gallagher)
Licensed under Unlicense 
http://github.com/necolas/css3-github-buttons
------------------------------------------ */


/* ------------------------------------------------------------------------------------------------------------- BUTTON */

.button { 
    position: relative; 
    overflow: visible; 
    display: inline-block; 
    padding: 0.5em 1em; 
    border: 1px solid #d4d4d4; 
    margin: 0;
    text-decoration: none; 
    text-shadow: 1px 1px 0 #fff; 
    font:11px/normal sans-serif; 
    color: #333; 
    white-space: nowrap; 
    cursor: pointer; 
    outline: none; 
    background-color: #ececec;
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(#f4f4f4), to(#ececec));
    background-image: -moz-linear-gradient(#f4f4f4, #ececec);
    background-image: -o-linear-gradient(#f4f4f4, #ececec);
    background-image: linear-gradient(#f4f4f4, #ececec);
    -webkit-background-clip: padding;
    -moz-background-clip: padding;
    -o-background-clip: padding-box; 
    /*background-clip: padding-box;*/ /* commented out due to Opera 11.10 bug */
    -webkit-border-radius: 0.2em; 
    -moz-border-radius: 0.2em; 
    border-radius: 0.2em; 
    /* IE hacks */
    zoom: 1; 
    *display: inline; 
}

.button:hover,
.button:focus,
.button:active,
.button.active {
    border-color: #3072b3;
    border-bottom-color: #2a65a0;
    text-decoration: none; 
    text-shadow: -1px -1px 0 rgba(0,0,0,0.3); 
    color: #fff; 
    background-color: #3C8DDE;
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(#599bdc), to(#3072b3));
    background-image: -moz-linear-gradient(#599bdc, #3072b3);
    background-image: -o-linear-gradient(#599bdc, #3072b3);
    background-image: linear-gradient(#599bdc, #3072b3);
}

.button:active,
.button.active {
    border-color: #2a65a0;
    border-bottom-color: #3884CF;
    background-color: #3072b3;
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(#3072b3), to(#599bdc));
    background-image: -moz-linear-gradient(#3072b3, #599bdc);
    background-image: -o-linear-gradient(#3072b3, #599bdc);
    background-image: linear-gradient(#3072b3, #599bdc);
}

/* overrides extra padding on button elements in Firefox */
.button::-moz-focus-inner {
    padding: 0;
    border: 0;
}

/* ............................................................................................................. Icons */

.button.icon:before {
    content: "";
    position: relative; 
    top: 1px; 
    float:left;
    width: 12px; 
    height: 12px; 
    margin: 0 0.75em 0 -0.25em; 
    background: url(gh-icons.png) 0 99px no-repeat;
}

.button.arrowup.icon:before { background-position: 0 0; }
.button.arrowup.icon:hover:before,
.button.arrowup.icon:focus:before,
.button.arrowup.icon:active:before { background-position: -12px 0; }

.button.arrowdown.icon:before { background-position: 0 -12px; }
.button.arrowdown.icon:hover:before,
.button.arrowdown.icon:focus:before,
.button.arrowdown.icon:active:before { background-position: -12px -12px; }

.button.arrowleft.icon:before { background-position: 0 -24px; }
.button.arrowleft.icon:hover:before,
.button.arrowleft.icon:focus:before,
.button.arrowleft.icon:active:before { background-position: -12px -24px; }

.button.arrowright.icon:before { float:right; margin: 0 -0.25em 0 0.5em; background-position: 0 -36px; }
.button.arrowright.icon:hover:before,
.button.arrowright.icon:focus:before,
.button.arrowright.icon:active:before { background-position: -12px -36px; }

.button.approve.icon:before { background-position: 0 -48px; }
.button.approve.icon:hover:before,
.button.approve.icon:focus:before,
.button.approve.icon:active:before { background-position: -12px -48px; }

.button.add.icon:before { background-position: 0 -288px; }
.button.add.icon:hover:before,
.button.add.icon:focus:before,
.button.add.icon:active:before { background-position: -12px -288px; }

.button.remove.icon:before { background-position: 0 -60px; }
.button.remove.icon:hover:before,
.button.remove.icon:focus:before,
.button.remove.icon:active:before { background-position: -12px -60px; }

.button.log.icon:before { background-position: 0 -72px; }
.button.log.icon:hover:before,
.button.log.icon:focus:before,
.button.log.icon:active:before { background-position: -12px -72px; }

.button.calendar.icon:before { background-position: 0 -84px; }
.button.calendar.icon:hover:before,
.button.calendar.icon:focus:before,
.button.calendar.icon:active:before { background-position: -12px -84px; }

.button.chat.icon:before { background-position: 0 -96px; }
.button.chat.icon:hover:before,
.button.chat.icon:focus:before,
.button.chat.icon:active:before { background-position: -12px -96px; }

.button.clock.icon:before { background-position: 0 -108px; }
.button.clock.icon:hover:before,
.button.clock.icon:focus:before,
.button.clock.icon:active:before { background-position: -12px -108px; }

.button.settings.icon:before { background-position: 0 -120px; }
.button.settings.icon:hover:before,
.button.settings.icon:focus:before,
.button.settings.icon:active:before { background-position: -12px -120px; }

.button.comment.icon:before { background-position: 0 -132px; }
.button.comment.icon:hover:before,
.button.comment.icon:focus:before,
.button.comment.icon:active:before { background-position: -12px -132px; }

.button.fork.icon:before { background-position: 0 -144px; }
.button.fork.icon:hover:before,
.button.fork.icon:focus:before,
.button.fork.icon:active:before { background-position: -12px -144px; }

.button.like.icon:before { background-position: 0 -156px; }
.button.like.icon:hover:before,
.button.like.icon:focus:before,
.button.like.icon:active:before { background-position: -12px -156px; }

.button.favorite.icon:before { background-position: 0 -348px; }
.button.favorite.icon:hover:before,
.button.favorite.icon:focus:before,
.button.favorite.icon:active:before { background-position: -12px -348px; }

.button.home.icon:before { background-position: 0 -168px; }
.button.home.icon:hover:before,
.button.home.icon:focus:before,
.button.home.icon:active:before { background-position: -12px -168px; }

.button.key.icon:before { background-position: 0 -180px; }
.button.key.icon:hover:before,
.button.key.icon:focus:before,
.button.key.icon:active:before { background-position: -12px -180px; }

.button.lock.icon:before { background-position: 0 -192px; }
.button.lock.icon:hover:before,
.button.lock.icon:focus:before,
.button.lock.icon:active:before { background-position: -12px -192px; }

.button.unlock.icon:before { background-position: 0 -204px; }
.button.unlock.icon:hover:before,
.button.unlock.icon:focus:before,
.button.unlock.icon:active:before { background-position: -12px -204px; }

.button.loop.icon:before { background-position: 0 -216px; }
.button.loop.icon:hover:before,
.button.loop.icon:focus:before,
.button.loop.icon:active:before { background-position: -12px -216px; }

.button.search.icon:before { background-position: 0 -228px; }
.button.search.icon:hover:before,
.button.search.icon:focus:before,
.button.search.icon:active:before { background-position: -12px -228px; }

.button.mail.icon:before { background-position: 0 -240px; }
.button.mail.icon:hover:before,
.button.mail.icon:focus:before,
.button.mail.icon:active:before { background-position: -12px -240px; }

.button.move.icon:before { background-position: 0 -252px; }
.button.move.icon:hover:before,
.button.move.icon:focus:before,
.button.move.icon:active:before { background-position: -12px -252px; }

.button.edit.icon:before { background-position: 0 -264px; }
.button.edit.icon:hover:before,
.button.edit.icon:focus:before,
.button.edit.icon:active:before { background-position: -12px -264px; }

.button.pin.icon:before { background-position: 0 -276px; }
.button.pin.icon:hover:before,
.button.pin.icon:focus:before,
.button.pin.icon:active:before { background-position: -12px -276px; }

.button.reload.icon:before { background-position: 0 -300px; }
.button.reload.icon:hover:before,
.button.reload.icon:focus:before,
.button.reload.icon:active:before { background-position: -12px -300px; }

.button.rss.icon:before { background-position: 0 -312px; }
.button.rss.icon:hover:before,
.button.rss.icon:focus:before,
.button.rss.icon:active:before { background-position: -12px -312px; }

.button.tag.icon:before { background-position: 0 -324px; }
.button.tag.icon:hover:before,
.button.tag.icon:focus:before,
.button.tag.icon:active:before { background-position: -12px -324px; }

.button.trash.icon:before { background-position: 0 -336px; }
.button.trash.icon:hover:before,
.button.trash.icon:focus:before,
.button.trash.icon:active:before { background-position: -12px -336px; }

.button.user.icon:before { background-position: 0 -360px; }
.button.user.icon:hover:before,
.button.user.icon:focus:before,
.button.user.icon:active:before { background-position: -12px -360px; }


/* ------------------------------------------------------------------------------------------------------------- BUTTON EXTENSIONS */

/* ............................................................................................................. Primary */

.button.primary {
    font-weight: bold;
}

/* ............................................................................................................. Danger */

.button.danger {
    color: #900;
}

.button.danger:hover,
.button.danger:focus,
.button.danger:active {     
    border-color: #b53f3a;
    border-bottom-color: #a0302a;
    color: #fff; 
    background-color: #dc5f59;
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(#dc5f59), to(#b33630));
    background-image: -moz-linear-gradient(#dc5f59, #b33630);
    background-image: -o-linear-gradient(#dc5f59, #b33630);
    background-image: linear-gradient(#dc5f59, #b33630);
}

.button.danger:active,
.button.danger.active {   
    border-color: #a0302a;
    border-bottom-color: #bf4843;
    background-color: #b33630;
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(#b33630), to(#dc5f59));
    background-image: -moz-linear-gradient(#b33630, #dc5f59);
    background-image: -o-linear-gradient(#b33630, #dc5f59);
    background-image: linear-gradient(#b33630, #dc5f59);
}

/* ............................................................................................................. Pill */

.button.pill {
    -webkit-border-radius: 50em; 
    -moz-border-radius: 50em; 
    border-radius: 50em; 
}

/* ............................................................................................................. Disable */

.button.disable {
    opacity: 0.5;
}

/* ............................................................................................................. Big */

.button.big {
    font-size: 14px; 
}

.button.big.icon:before { top: 0; }

/* ............................................................................................................. Huge */

.button.huge {
    font-size: 54px; 
}

.button.huge.icon:before { top: 0; }

/* ------------------------------------------------------------------------------------------------------------- BUTTON GROUPS */

/* ............................................................................................................. Standard */

.button-group {
    display: inline-block;
    list-style: none;
    padding: 0;
    margin: 0;
    /* IE hacks */
    zoom: 1; 
    *display: inline; 
}

.button + .button,
.button + .button-group,
.button-group + .button,
.button-group + .button-group {
    margin-left: 15px;
}

.button-group li {
    float: left;
    padding: 0;
    margin: 0;
}

.button-group .button {
    float: left;
    margin-left: -1px; 
}

.button-group > .button:not(:first-child):not(:last-child),
.button-group li:not(:first-child):not(:last-child) .button { 
    -webkit-border-radius: 0; 
    -moz-border-radius: 0; 
    border-radius: 0; 
}

.button-group > .button:first-child,
.button-group li:first-child .button { 
    margin-left: 0; 
    -webkit-border-top-right-radius: 0; 
    -webkit-border-bottom-right-radius: 0; 
    -moz-border-radius-topright: 0; 
    -moz-border-radius-bottomright: 0; 
    border-top-right-radius: 0; 
    border-bottom-right-radius: 0; 
}

.button-group > .button:last-child,
.button-group li:last-child > .button { 
    -webkit-border-top-left-radius: 0; 
    -webkit-border-bottom-left-radius: 0; 
    -moz-border-radius-topleft: 0; 
    -moz-border-radius-bottomleft: 0; 
    border-top-left-radius: 0; 
    border-bottom-left-radius: 0; 
}

/* ............................................................................................................. Minor */

.button-group.minor-group .button {
    border: 1px solid #d4d4d4; 
    text-shadow: none;
    background-image: none;
    background-color: #fff;
}

.button-group.minor-group .button:hover,
.button-group.minor-group .button:focus {
    background-color: #599bdc;
}

.button-group.minor-group .button:active,
.button-group.minor-group .button.active {
    background-color: #3072b3;
}

.button-group.minor-group .button.icon:before {
    opacity: 0.8;
}

/* ------------------------------------------------------------------------------------------------------------- BUTTON CONTAINER */
/* For mixing buttons and button groups, e.g., in a navigation bar */

.button-container .button,
.button-container .button-group {
    vertical-align: top;
}

index.html

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8">
    <title>How to develop a jQuery plugin with CoffeeScript</title>
    <meta name="description" content="How to develop a jQuery plugin with CoffeeScript">

    <link rel="stylesheet" href="gh-buttons.css">
    <link rel="stylesheet" href="main.css">
    <body>

    <a href="http://example.com" class="button huge danger" data-external="true" data-confirm="Are you sure you want to leave us?" rel="nofollow">Explicit Confirm</a>
    <a href="http://example.com" class="button huge danger" data-external="true" rel="nofollow">Default Confirm</a>
    <input type="button" value="Default Confirm, Explicit Url" class="button huge danger" data-external="true" data-url="http://example.com" rel="nofollow" />

    <script src="http://code.jquery.com/jquery-1.6.4.min.js"></script>
    <script src="jquery.externalurl.js"></script>
    <script>
        $(document).ready(function() {
            // create new instance of plugin
            var plugin = new $.externalurl();
        });
    </script>
</body>
</html>

jquery.externalurl-generated.js

(function() {
  (function($) {
    return $.externalurl = function(el, options) {
      var defaults, externalurl, init;
      defaults = {
        messageStay: "Thanks for sticking with us!",
        messageConfirm: "Are you sure you want to leave us?"
      };
      externalurl = this;
      externalurl.settings = {};
      init = function() {
        externalurl.settings = $.extend({}, defaults, options);
        externalurl.el = el;
        externalurl.selector = "[data-external]";
        return $(this).delegate(externalurl.selector, "click", function(e) {
          var ask, url;
          e.preventDefault();
          url = $(this).data("url") || this.href;
          ask = $(this).data("confirm") || externalurl.settings.messageConfirm;
          if (!url) {
            return false;
          }
          if (confirm(ask)) {
            return window.location.href = url;
          } else {
            return alert(externalurl.settings.messageStay);
          }
        });
      };
      return init();
    };
  })(jQuery);
}).call(this);

jquery.externalurl.coffee

(($) ->
  $.externalurl = (el, options) ->

    defaults =
      messageStay:    "Thanks for sticking with us!"
      messageConfirm: "Are you sure you want to leave us?"

    externalurl          = @
    externalurl.settings = {}

    init = ->
      externalurl.settings = $.extend({}, defaults, options)
      externalurl.el       = el
      externalurl.selector = "[data-external]"

      $(this).delegate externalurl.selector, "click", (e) ->
        e.preventDefault()

        url = $(this).data("url") or @href
        ask = $(this).data("confirm") or externalurl.settings.messageConfirm

        return false unless url

        if confirm(ask)
          window.location.href = url
        else
          alert externalurl.settings.messageStay

    init()
) jQuery

jquery.externalurl.js

// semicolon to mitigate concatenation problems
;(function($) {

    // plug-in name
    $.externalurl = function(el, options) {

        // default options (private; accessible only from inside the plugin)
        var defaults = {
            messageStay:    'Thanks for sticking with us!',
            messageConfirm: 'Are you sure you want to leave us?',
        };

        // be explicit when referencing current instance of the object
        var externalurl      = this;
        externalurl.settings = {};

        // "constructor" method that gets called when the object is created
        var init = function() {

            // merged default and user-provided options
            externalurl.settings = $.extend({}, defaults, options);

            // make target element(s) collection available
            externalurl.el = el;

            // selector reference string (keeping it DRY)
            externalurl.selector = '[data-external]';

            // handle click event on selected elements
            $(this).delegate(externalurl.selector, 'click', function(e) {
                e.preventDefault();
                var url = $(this).data('url')     || this.href,
                    ask = $(this).data('confirm') || externalurl.settings.messageConfirm;

                // do nothing if URL is not specified
                if (!url) { return false; }

                if (confirm(ask)) {
                    // leave
                    window.location.href = url;
                } else {
                    // stay
                    alert(externalurl.settings.messageStay);
                }
            });
        }

        // call the "constructor" method
        init();
    }

})(jQuery);

main.css

body {
     margin: 250px 0px;
    padding: 0px; text-align:center;
}

.button {
    margin: 15px 0;
}