Question

I would like to have a button that changes data-icon class depending upon user selections

Example button would be:

<a href="#language2" data-rel="popup" data-role="button" 
                     data-icon="english-flag" data-inline="true" 
                     data-position-to="origin">
    <span id="language3">English</span>
</a>

I’d like to know what javascript code I would need to implement in order to change the custom defined data-icon="english-flag" to be instead data-icon="another-flag"

Thanks in advance.

Edit: The answer to my followup questions below on how to specify which button to affect can be found at;
How to change a specific JQuery Mobile button icon with javascript

Answer 1

jQuery Mobile has a predefined function:

$('a').buttonMarkup({ icon: "star" });

It is not enough to change an attribute, final button restyling must be done with .buttonMarkup( function.

Here’s an official documentation: http://jquerymobile.com/demos/1.2.0/docs/buttons/buttons-options.html

And here’s an example: http://jsfiddle.net/Gajotres/AmFKa/

Also, because you are creating a custom button it wont be enough just to change icon name, first you need to define it in your css like this:

<style type="text/css">
    .ui-icon-edit {
       background-image: url(icons-18-white.png); // This should be your picture
       background-repeat: no-repeat;
       background-position: -824px 50%;
    }
</style>

We would add this new icon like this:

$('a').buttonMarkup({ icon: "edit" });

In this case we are adding picture edit. Now notice its cass name .ui-icon-edit, to add a new icon class you need to combine a .ui-icon- string with a icon name. In your case your class name would be .ui-icon-another-flag.