Bug 61473 – REGRESSION (r67163): twitter.com doesn't load properly the first time

• Status: RESOLVED
• Resolution: FIXED
• Component: DOM

[Andy Estes]

In some cases, twitter.com fails to load the timeline with a cold cache. The black toolbar loads, but a JavaScript error prevents the rest of the page from loading. The error is typically something like:

TypeError: 'undefined' is not an object (evaluating 'twttr.anywhere.api')

See the attached screenshot to see what the page looks like when this happens.

The problem seems to be specific to a subset of twitter accounts and usually goes away if you reload the page. Since I am able to see this error, I'll work on a reduction.

[Andy Estes]

<rdar://problem/9491632>

[Andy Estes]

This is a regression due to <http://trac.webkit.org/changeset/67163>

[Andy Estes]

There is a JavaScript function in the main document called initAPI() that calls twttr.anywhere.api.initialize().

twttr.anywhere.api is defined in an external resource that is included earlier in the main document using:
<script type="text/javascript" async="" src="https://si1.twimg.com/a/1306171173/javascripts/api.bundle.js"></script>

Since the script tag has the async attribute, it can load after initAPI() executes. Sounds like a race condition.

[Adam Barth]

Sounds like we should evangelize them to not use async and rely on script ordering!

[Theresa O'Connor]

I've evang'ed; they already knew about this, and have a fix on the way.

[Andy Estes]

(In reply to comment #5)
> I've evang'ed; they already knew about this, and have a fix on the way.

That's great! Do you have any sense of timeframe so we know when to verify the fix?

[Theresa O'Connor]

I'll ask.

[Elliott Sprehn]

They don't even include the referenced script anymore and it appears they're using async more carefully.