I hope the below snippet might help, you can specify the content
value you want via JS using the CSS attr()
function.
Below you have two options: to use JavaScript or jQuery:
jQuery:
$('.graph').on('click', function () {
//do something with the callback
$(this).attr('data-before','anything'); //anything is the 'content' value
});
JavaScript:
var graphElem = document.querySelector('.graph');
graphElem.addEventListener('click', function (event) {
event.target.setAttribute('data-before', 'anything');
});
CSS:
.graph:before {
content: attr(data-before); /* value that that refers to CSS 'content' */
position:absolute;
top: 0;
left: 0;
}