Get Pseudo-Element Properties with JavaScript

Discussion

1. MaxArt

   Yeah, too bad this doesn’t work with IE8 and previous.
   currentStyle is good for some things, but… not for this one.
2. MaxArt

   By the way, I forgot to say that it’s usually recommended to use document.defaultView.getComputedStyle instead of window.getComputedStyle, because there are cases where document.defaultView !== window.

   I don’t know which ones, though. I guess it’s not the case of “common” web pages.
• Martin

  From the MDN documentation:

  In many code samples online, getComputedStyle is used from the document.defaultView object. In nearly all cases, this is needless, as getComputedStyle exists on the window object as well. It’s likely the defaultView pattern was some combination of (1) folks not wanting to write a spec for window and (2) making an API that was also usable in Java. However there is a single case where the defaultView’s method must be used: when using Firefox 3.6 to access framed styles.

  https://developer.mozilla.org/en-US/docs/DOM/window.getComputedStyle
3. Devang Paliwal

   Very useful! I ran across this scenerio many times where i wanted to access the psedo element props.
4. Toni Michel

   Nice!

   Long time a go I was looking for a way to bind events on pseudo elements, is that posible today?

   Thanks!
• David Walsh

  I don’t believe that’s possible yet Toni!
5. Melih O.

   Thanks for this solution. Was looking for this!
6. Hal D.

   With content:url(“some image”) as a property Firefox correctly gets that string using any of these three methods:

   getComputedStyle(someelement,"::after").getPropertyValue("content")
   getComputedStyle(someelement,"::after").content
   getComputedStyle(someelement,"::after")..getPropertyCSSValue("content").cssText
   

   None of these methods work in Chrome, they either return null or undefined. What gives?
• Hal D.

  Never mind, I found the issue is the element must not be display:none to access it according to https://code.google.com/p/chromium/issues/detail?id=236603
7. gaurav

   Is there a way, we can set the pseudo style value back in css?
8. sgaawc

   Pseudo Element’s integration with Javascript is new to me. I will make sure to give it a try and see how it works with diff browsers. but I wonder if there is any way to associate handlers to these elements.

   Thanks.
9. Lore

   How would you make a function that could reference self?
   When I place this in a jQuery function and try to replace $('.element') with ($(this)), I have issues.
• Neeph

  Did you ever find a way to use ($(this))?
10. Craig

    How about when the desired element is a child of an :active element? Like:

    .parent:active .child {
      display: inline-block
    }
    
• Shakey

  :active is a pseudo class, not a pseudo element, so you can’t grab it with getComputedStyle
11. Max

    Great Post! However, the code gives me the certain values like height and top as px in Chrome and as % in Firefox and IE. Anyway to get a consistent result for all browsers?
12. Emeka

    I am looking to bind event to pseudo classes with vanilla javascript. Isn’t there a hack already
13. Roshan Karmacharya

    like getPropertyValue, is there any setProperty methods that can replace the contents?