Twitter decided to give a nice Happy Halloween to users today in the form of radically changing the site’s design and modifying tweets upon an update containing solely “#trick” or “#treat” tweeted from its standard web client.

Below are some screenshots of this temporary feature (for historic purposes) and a little information about it.

Article Sections:
#treat
#trick
Technical Details
Final Notes
Update: Screencast Added

#treat

Although not nearly as interesting as it’s Halloween-themed counterpart, the #treat update displayed this design over the timeline:

But the #treat easter-egg isn’t nearly as fun as the #trick easter-egg:

#trick

First, right after the update solely containing ‘#trick’ is “published”, this drop-down message is displayed after the new background is loaded:

Then, after a progressive timeline/tweet modification, the next change appeared:

By far, this was my favorite modification of the two. Also, it earns more of an ‘easter-egg’ status than the former because I don’t recall ever seeing #trick trending throughout the day as I did #treat.

How it works

This is a little techy, but basically Twitter added a hook into their JavaScript’s AJAX tweet-publishing code that did some simply string matching to detect the single strings “#trick” or #”treat”, in order to perform a special action in response.

The background of the page, at least in the case of the #trick’s biohazard image, is a transparent PNG laid over the page’s background. I know this without even looking at the code because the coffee-colored background was visible under the biohazard image before it was changed to black to further complete the process of setting the new design.

The usual now-famous Twitter drop-down box was recycled for the “Happy Halloween” message, only using a black background with a yellow Arial(?) font in the case of the #trick design. I assume absolute-positioned transparent PNGs are what allowed the spider webs/witches to lie over the drop-down messages.

And note that the tweet is never published – some hard-wired control flow code prevents it from reaching Twitter’s servers in favor of redesigning the client’s appearance.

Enjoy!

I saved the screenshots in case someone missed it, and for historic purposes.

I actually discovered this by simply seeing people tweet about #trick/#treat (with other words in their tweet) and by seeing #treat within the Trending Topics.

Twitter actually provided a description for the egg within the trending topic for #treat. Without their explicitly stating it, I (and presumably other users) would have never thought to tweet JUST #trick or #tweet. Besides, unless I’d already seen it I’d look like a spammer or idiot with a published tweet containing only #trick or #tweet.

But, that said, I really enjoyed this new added feature today, along with Google’s “This space intentionally left blank” thing on their front page.

I hope everyone out there enjoyed this as much as I did!

Update: YouTube Screencast Now Available