PNG Transparency for Internet Explorer

Ever wanted to allow your users to see transparent PNG images using Internet Explorer? Now you can!

[high]Note:[/high] I did NOT create this script, it remains the sole property of it's author.


Pros & Cons

Pros:

• Ignored as a comment in other browsers, so no browser-sniffing code is required
• Works with (X)HTML Strict & Transitional Doctypes
• Does not break W3C validation
• Lightweight and very easily deployed
• Works with existing in-line or external CSS rules based on class or ID selectors
• Works with old-style img align="left" or align="right" attributes
• Adds itself to the end of any existing Body Onload code
• Works with imagemaps and input images using a special version

Cons:

• Doesn't work in IE versions earlier than 5.5
• Requires JavaScript to be enabled - the estimations for how many people choose not to use JS vary wildly.
• CSS backround PNGs not supported - experimentation revealed I could traverse the Stylesheets collection and use the AlphaImageLoader trick to replace all background-image attributes containing PNGs, but then background-repeat would not work, and anchors placed over non-transparent parts of the image were not clickable :-(
• CSS rules for the PNG images based on the img selector are lost, but this is easily rectified by adding a class selector to your img rule such that img{..} becomes img,.png{..} - then add the attribute class="png" to each of your PNGs.

To install, simply upload the attached .js file to your /forums/clientscript/ directory.

Then edit your headinclude template, and add the following:

<!--[if lt IE 7.]>
<script defer type="text/javascript" src="clientscript/vbulletin_pngfix.js?v=$vboptions[simpleversion]"></script>
<![endif]-->

You're all set.!
Note: Updated to reflect changes by the author, and 3.5.x javascript handling changes. This template modification works fine with 3.6.x as it is, and therefore won't be posted in the 3.6.x forum!

[Floris]

Very cool to share this, many will want this and especially nice to see the pros/cons against eachother. Good job.

[Adrian Schneider]

Thanks, works great.

[Bad Bunny]

Originally Posted by TheSpecialist

Thanks, works great.

It doesn't seem to do anything for me. I am using rc1

[Adrian Schneider]

I think you have to do a hard refresh for the new JS files to load.
Ctrl F5

[Oblivion Knight]

Failing that; What version of Internet Explorer are you using and do you have javascript enabled?

[Bad Bunny]

Yeah, I restarted IE. I appreciate the work you did, and it must be good stuff. But I ended up using a different method. But thank you!

[Wayne Luke]

Great to see a solution which doesn't require modifying the PHP or how images are called. I used it to upload all new PNG emoticons to my site and it works great. Going to replace the icons with PNG tomorrow.

Hopefully since IE7 should support this transparently, more webmasters will start using PNGs to their full potential and we can see some cool things because of it.

[Rhoads]

Nice, installed in 5 sec and working perfectly :nervous:

[TheFocusElf]

sure, this mod is no catch all -- but I do like that it does address the issue.

-installed-