hacks.mozilla.org

Robert O’Callahan has been posting updates in his weblog about changes that we’re going to be making that are web-facing. It’s worth summarizing two here for web developers.

Removing the media element ‘load’ event.

Yesterday I checked in a patch that removes support for the ‘load’ event on <video> and <audio> elements. We simply never fire it. Also, the networkState attribute is now never NETWORK_LOADED. When we’ve read to the end of the media resource, networkState changes to NETWORK_IDLE. We plan to ship this change for Firefox 3.6.

This API has been removed based on consensus from everyone who are doing HTML5 video implementations and there are lots of other options for events that Robert goes over in his post.

Changing our CSS Gradient Syntax

We landed support for a form of CSS gradients on trunk a while ago, but we got considerable feedback that our syntax — which was an incremental improvement of Webkit’s syntax, which basically exposes a standard gradient API in the most direct possible way — sucked. A bunch of people on www-style got talking and Tab Atkins produced a much better proposal. Since we haven’t shipped our syntax anywhere yet, dropping it and implementing Tab’s syntax instead was a no-brainer. So Zack Weinberg, David Baron and I did that (using a -moz prefix of course), and today it landed on trunk. It should land on the Firefox 3.6 branch shortly. It’s unfortunate to land something new like this after the last beta, but in this case, it seems like the right thing to do instead of shipping CSS gradient syntax that we know nobody wants.

We’ve never shipped the “bad” CSS gradient syntax in a final release, but it is in our first beta. We’ll be updating it before we make our final release of 3.6. Stay turned for the new syntax on hacks.

I asked this on the mozhacks twitter account earlier today but I’d like to get more feedback:

what’s your single favorite thing about hacks.mozilla.org?

The survey is totally anonymous and takes 20 seconds or so. It’s limited, much like twitter, to a very short response. If you have ideas on improvement there’s room for that as well so please, respond away! If we get enough good feedback we’ll post results here as well.

Thanks!

This post is from Doug Turner who has previous written about Geolocation. Doug works on Mozilla’s mobile project.

XMLHttpRequests (XHR) can be either synchronous or asynchronous. Although most people use asynchronous requests there are instances where you might want to use a synchronous request. That is, wait until the XMLHttpRequest call completes to continue executing JavaScript. In Firefox 3 and earlier the browser would still fire timer events and respond to input events during a synchronous XHR request. In Firefox 3.5 and later input events such as mouse moves and timeouts will be suspended until the synchronous request completes. This allows the synchronous request to block.

For example:

function hello() {
     alert(“hello”);
}
 
setTimeout(hello, 20);
 
var req = new XMLHttpRequest();
req.open('GET', 'http://www.mozilla.org/', false);
req.send(null);

Prior to Firefox 3.5, it was impossible to determine if the “hello” function would be invoked during or after the XHR request. This led to all sorts of timing issues in web applications that used synchronous XHR requests.

The solution to this problem has been to delay input events and timeouts until after “req.send” returns.

For more information see the two bugs on the issue.