Are You Sure? - A light "dirty forms" JQuery Plugin!

Are-you-sure (jquery.are-you-sure.js) is simple light-weight "dirty form" JQuery Plugin for modern browsers. It helps prevent users from losing unsaved HTML Form changes.

It's simple to use. Just add the following line to your page's ready function:

$('form').areYouSure();

Are-you-sure is a minimal plugin for modern browsers. There are plenty of "dirty forms" implementations out there, however they all seemed very heavyweight and over-engineered...! Most were written some time back and contain many 'hacks' to support legacy browsers, and/or rely on other fat dependencies such as FaceBox or jQueryUI. Are-you-sure solves this by doing this simple task in the simplest possible way.

Are-you-sure is as simple as it gets:

• 100% JS with zero dependencies and no external CSS.
• Leverages onBeforeUnload to detect all page/browser exit events.
• Works on forms of any size.
• Correct state management - if a user edits then restores a value, the form is not considered dirty.
• Easy to understand - less than a "terminal screen" of code!
• Graceful degradation on legacy browsers (i.e. if you're running an old browser... remember to save :-)

###Usage

$(function() {

    // Enable on all forms
    $('form').areYouSure();

    // Enable on selected forms
    $('form.dirty-check').areYouSure();

    // With a custom message
    $('form').areYouSure( {'message':'Your profile details are not saved!'} );

    // Test if a form is dirty in your own code
    if ($('#my-form').hasClass('dirty')) {
        // Do something
    }

    // Advanced: Hook a dirty change event to enable the "save" button.
    $('#my-adv-form').areYouSure( {
        change: function() {
                  // Enable save button only if the form is dirty. i.e. something to save.
                  if ($(this).hasClass('dirty')) {
                    $(this).find('input[type="submit"]').removeAttr('disabled');
                  } else {
                    $(this).find('input[type="submit"]').attr('disabled', 'disabled');
                  }
                }
      } );
    
}

To ignore selected fields from the dirtyness check:

  <form id="myForm" name="myform" action="/post" method="post">

    Field 1: (checked)                  <input type="text" name="field1"> <br />
    Field 2: (ignored with attribute):  <input type="text" name="field2" data-ays-ignore="true"> <br />
    Field 3: (ignored with class):      <input type="text" name="field3" class="ays-ignore"> <br />

    <input type="submit" value="Submit">

  </form>

###Install This plugin is very light weight. You could download the jquery.are-you-sure.js file however my recommendation is to simply cut-n-paste the code (and license header) into one of your existing JavaScript files... it seems a shame to add an extra browser round trip for such a simple feature :-)

###Demo This demo page hosts a number of example forms.

###Known Issues & Limitations

• The custom message option may not work on Firefox (Firefox bug 588292).
• The windows.beforeunload event is not supported on current Opera (Feb 2013). This will change with their move to WebKit.

###Future The aim is to keep Are-you-sure simple and light. If you think you have a good idea which is aligned with this objective, please voice your thoughts in the issues list.

###Release History

2013-05-01 - Added support for hidden and disabled form fields.

2013-02-03 - Add demo page.

2013-01-28 - Add change event support and a demo page.

2012-10-26 - Use dashes in class names rather than camel case.

2012-10-24 - Initial public release.

###Prerequisites jQuery version 1.4.2 or higher.

###License The same as JQuery...

jQuery Plugin: Are-You-Sure (Dirty Form Detection)
https://github.com/codedance/jquery.AreYouSure/

Copyright (c) 2012-2013, Chris Dance - PaperCut Software http://www.papercut.com/
Dual licensed under the MIT or GPL Version 2 licenses.
http://jquery.org/license