javascript - How to Determine if ::before is applied to an element?

Question

I have this simple html code. I need to be able to determine if the ::before is being applied to .icon-player-flash

    <div id="TestSwitch">

        <i class="icon-player-html5"></i>

        <i class="icon-player-none"></i>

        <i class="icon-player-flash"></i>

    </div>

I thought this would work but it's always returning 0 for the length.

var flashplayer = $(".icon-player-flash:before");
console.log("count: " + flashplayer.length);

What am I missing?

Answer 1

Use getComputedStyle and check the value of content. If it's none then the pseudo element isn't defined:

var elem = document.querySelector(".box");
var c = window.getComputedStyle(elem,"before").getPropertyValue("content");
console.log(c);

var elem = document.querySelector(".alt");
var c = window.getComputedStyle(elem,"before").getPropertyValue("content");
console.log(c);

.box:before {
  content:"I am defined"
}

<div class="box"></div>

<div class="alt"></div>