Twitter bootstrap 3.0 icon change on collapse

Question

This is about Bootstrap 3.0. I would like the icon/glyphicon to change on collapse. I.e, from a closed folder to an open one.

I have searched far and wide, and have

Answer 1

This code finds your accordion with the ID of 'Accordion'. When the shown event fires on the collapsed panel, the icon is found in the header panel (the previous element) and it finds and changes your glyph icon element within that HTML code block:

$('#accordion .panel-collapse').on('shown.bs.collapse', function () {
    $(this).prev().find(".glyphicon").removeClass("glyphicon-chevron-right").addClass("glyphicon-chevron-down");
});

//The reverse of the above on hidden event:

$('#accordion .panel-collapse').on('hidden.bs.collapse', function () {
    $(this).prev().find(".glyphicon").removeClass("glyphicon-chevron-down").addClass("glyphicon-chevron-right");
});