Today we released Sencha Touch 2.0 PR4 - the fourth and final preview release before we hit beta. While we're technically calling this one a preview release, we're pretty happy with the performance, stability and overall quality of this release and consider it exceptionally close to beta quality.

As well as a good number of enhancements and bug fixes PR4 brings a couple of long-awaited improvements to two of the most important parts of Sencha Touch - the data package and the application architecture.

First up, the data package has been ported to use the new config system, which normalizes all of the configuration options for every class in the data package, providing a clean and predictable way to configure and update your data classes. We're still cleaning up some of the data package documentation and given the scope of some of the changes we're expecting a few bugs to appear as a result but overall we're very happy with the improved capabilities of Ext.data.

MVC Improvements

The second big improvement in PR4 is to the application architecture. The MVC classes have also been upgraded to use the new config system, again yielding big improvements in the API and general flexibility of your code.

History support has been baked directly into Controllers, enabling you to easily define routes that your Controller cares about, as well as the functions that handle those routes right there in your Controller file. The Kitchen Sink example has been upgraded to use routes out of the box - try it on a mobile device or desktop browser and watch how it reacts to the back/forward buttons.

Equally important, Device Profiles have been upgraded to make creating apps that adapt to different screen sizes much simpler than ever before. Once again the Kitchen Sink has been upgraded to take advantage of device profiles. If you load it on a tablet device you'll see a split screen view with the menu on the left and the content on the right, whereas the phone version employs a nested list to save screen space.

To cap it off the deep linking support means you can navigate to any view on a phone, send the link to a friend on a tablet and they'll be taken to the same view customized for their screen size. As an example, try opening http://dev.sencha.com/deploy/sencha-touch-2-pr4/examples/kitchensink/#demo/forms on a tablet and a phone to see it show the Forms demo specialized for each type of device.

As PR4 is the first time we've exposed this expanded functionality to the public we expect that there will be bugs and edge cases that crop up. We'll be keeping a close eye on the bug forums and addressing any issues as quickly as possible, as well as creating additional MVC-driven examples for you to learn from. For now, the kitchen sink is the best example of Sencha Touch 2 MVC in action.

Docs

We've made a huge push over the last couple of years to radically improve our documentation, and I think that even in the pre-beta PR4 release Sencha Touch 2 has the best docs we've ever created. While there are still holes to be filled in, we already ship with 20 guides on how to use the framework, including 4 brand new guides for PR4:

• Migrating from 1.x
• Intro to MVC
• Using Device Profiles
• Using Controllers

As well as the guides, most of the classes now contain generous documentation explaining their function and the context in which they operate. As we move to beta and then to GA we'll be shifting our focus onto producing great demos and examples to showcase the framework's capabilities and provide realistic sample code to draw from.

There's a full set of release notes explaining the improvements in PR4 and the important known issues. We expect to be shipping regular releases from now until GA so be sure to keep an eye on the forums, twitter and the sencha blog for more details.