display image caption in DNN using longdesc img attribute

dnn-captions.js

$('.ModDNNHTMLC img').each(function(i) {
        var img = $(this),
        width = $(this).css('width'),
        imageCaption = $(this).attr('longdesc'),
        figure
	if(imageCaption){
		if (img.css('float') == 'left') {
			img.css('float', '');
			figure = $('<figure class="alignleft"></figure>').css('width', width).css('float', 'left');
			img.wrap(figure);
			img.parent('figure').append('<figcaption>' + imageCaption + '</figcaption>');
		} else if (img.css('float') == 'right') {
			img.css('float', '');
			figure = $('<figure class="alignright"></figure>').css('width', width).css('float', 'right');
			img.wrap(figure);
			img.parent('figure').append('<figcaption>' + imageCaption + '</figcaption>');
		} else {
			img.css('float', '');
			figure = $('<figure class="alignright"></figure>').css('width', width).css('float', 'right');
			img.wrap(figure);
			img.parent('figure').append('<figcaption>' + imageCaption + '</figcaption>');
		}
	}
});

Updated to support DNN 7 only modifying images inside the HTML module. Also automatically adds the float right/left directing to the figure tag.