Oct 25, 2012 – By Peter Wagenet

Ember 1.0 Prerelease 2 is out now. This is mainly a bug fix release after 1.0.pre. However, there are a few things you should be aware of and we'll go over those a bit below. We're still pushing hard toward the a 1.0 beta release but wanted to make some of our bug fixes available in a more formal way. If you want to go ahead and download now, you can grab it over on the Github Download Page.

What's Changed Now

Other than bug fixes, there are a few things we've changed that could affect your 1.0.pre apps.

• {{outlet}} now creates a Metamorph rather than a <div>. This makes it less obtrusive, but you may have to change your HTML or CSS if you were relying on the <div>.
• We have removed CP_DEFAULT_CACHEABLE and VIEW_PRESERVES_CONTEXT flags. Both behaviors are now always on.
• Inline Handlebars templates must always be named now. The default name is 'application'. This means that <script type="text/x-handlebars"> behaves exactly the same as <script type="text/x-handlebars" data-template-name="application">.
• Using the {{collection}} helper without a class has been deprecated, use the {{each}} helper instead. The {{each}} helper also now supports itemViewClass which was the main benefit to using {{collection}}.
• Ember.ViewState has been removed.

For more information on what's been changing in Ember, take a look at Bradley Priest's What's New in EmberJS.

What Will Change Later

There are still some things that we want to take care of before we do a beta release. Here are a few of them:

• New Router API: This is mostly finalized but has not yet been implemented.
• New Computed Property API: We're working on a new API for Computed Property getters and setters. Don't worry, we expect to support the existing one for the foreseeable future.
• Asynchronous Observers: Currently observers are fired immediately whereas bindings are synchronized with the RunLoop. In most cases observers can and should be delayed for optimal performance. We plan to change the existing behavior and add a new API for the cases where immediate execution really is needed.