Copyright 2011, Tobias Toft, IDEO Llc

• Thanks to the brilliant people behind JQuery http://jquery.com
• JQuery UI http://jqueryui.com
• And the jquery-json plugin http://code.google.com/p/jquery-json/

6 September 2011

Replaces any DOM element with a segmented slider. The slider contains a hidden form field with the same name as the replaced element, containing the output values from the slider. The output values are returned as a JSON string with the same format as the string used to set up the slider.

The slider is built on JQuery 1.6.2 and JQuery UI 1.8.16. These are included in this package, however, can be left out if the site is already using JQuery.

The following files would normally need to be included in the html:

<!-- JQuery -->
<link type="text/css" href="css/ui-lightness/jquery-ui-1.8.16.custom.css" rel="stylesheet" />	
<script type="text/javascript" src="jquery-1.6.2.min.js"></script>
<script type="text/javascript" src="jquery-ui-1.8.16.custom.min.js"></script>
<script type="text/javascript" src="jquery.json-2.2.min.js"></script>

<!-- RatioSlider -->
<link rel="stylesheet" type="text/css" href="css/ratioslider.css" />
<script type="text/javascript" src="ratiosegment.js"></script>
<script type="text/javascript" src="ratioslider.js"></script>

Alternatively, instead of ratiosegment.js and ratioslider.js the file 'ratioslider.min.js' can be used, which is a minified version of the two uncompressed files. It has been compressed using Google's Closure Compiler. See 'example.min.htm' for an example. Please note, that since this is relying on the JQuery document.ready() function, the CSS for the slider needs to be loaded before the JS.

There are two ways of configuring the slider. It can be done as a part of the creation of the RatioSlider object or the configuration can be stored in the form field that the slider is replacing. In any case, the slider is set up by passing it a JSON string containing the desired segments and the total value (e.g. 130% for overprovisioning).

A new slider is configured like this:

var mySlider = new RatioSlider(DOMobject, config);

Where DOMobject is the object to replace (e.g. a text field). The 'config' parameter is optional, if omitted the RatioSlider class will look for a suitable configuration string in the DOMobject's 'value' field.

The JSON configuration format looks like this:

{"segments":{
	"Segment A":0.4,
	"Segment B":0.3,
	"Segment C":0.3,
	},
	"total":110
}

The 'segments' portion defines the segments by name and initial value. NOTE: The values are always fractions of 1, even when overprovisioning.

The 'total' is the total percentage, normally 100% but when over- or underprovisioning it will be e.g. 70% or 130%. The segments are always calculated as fractions of 1.

Here's an example of a slider that will replace the form element named "ratioslider2":

var rs2 = new RatioSlider("ratioslider2", {"segments":{"Cheese burger":0.4,"Kebab":0.3,"Falafel":0.1,"Hot dog":0.2},"total":130});

Please see the included 'example.htm' for an example of two sliders and example.min.htm for a version using the minified JS. The visual design of the sliders is defined in the 'css/ratioslider.css' file.

Please note that this is a very early and not very thoroughly tested version of the slider.