The Acre development team is proud to announce the release of Acre dev/20, which we consider the first ‘release candidate’ for Acre 1.0.

This release introduces a considerable amount of improvements in both the app editor and in the Acre engine itself.

APIs cleanup and deprecation

Acre APIs have grown organically, starting by emulating a simple CGI-like model. Over time, we realized that a request/response model was better suited for Acre apps.

This Acre release marks the deprecation of the old CGI-like model (for example, acre.environ.* and acre.context.*) and the official introduction of the new request/response objects (acre.request.* and acre.response.*) which are now the recommended way to interact with the HTTP request/response life cycle.

It is important to note that even if deprecated, all APIs are still available and will remain available for a few more releases: we understand that back-incompatible API transitions are highly disruptive and we want to minimize the impact we’re having on our community of developers. At the same time, we want to avoid disruption later and this is why we’re doing this transition now, before a 1.0 release.

It is worth noting that while Acre will execute apps that use deprecated APIs unchanged, it will also log ‘warning’ deprecation messages in the console (which can be obtained by adding setting the “acre.console=1″ parameter in every URL served by Acre).

We highly recommend following those deprecation warnings to update your apps to the new APIs, so that your app will continue to function in the future once the deprecated APIs will be turned off.

The new documentation hub (mentioned below) shows which API methods and variables have been deprecated and what are the new ones that should be used.

App Directory and Documentation Hub

Acre now has two important new visible parts: the app directory and the documentation hub.

• The app directory is the place for browsing and searching for apps. When you release an app to a short url it will be automatically added to the directory. You can edit its description, or even de-list it, in the General tab of the app menu (click on your app’s name) in the App Editor. Find the app directory at http://freebaseapps.com/apps
• The documentation hub is the place where you can find information about all the Acre APIs, the Freebase APIs and web services, the MQL language, etc. It’s still a work in-progress, but we’re also excited to introduce a new documentation viewer that brings together all of our reference documentation — for Acre, MQL and the Freebase Web Services. It’s both available in App Editor from the help menu, as well as stand-alone at http://freebaseapps.com/docs

App Editor

Several important improvements were made in Acre’s app editor:

• new query editor: guides you thru the creation of a MQL query with context-based auto-completion. It will also generate a simple acre template to generate an HTML page from your query and get you going faster. The keyboard shortcut for invoking “query assist” is the Tab key.
• code completion: app editor is now is capable of providing code-completion functionality and guide you during app development thru the discovery of Acre’s API and its parameters. The keyboard shortcut for invoking “code assist” is Alt-Space on the Mac and Ctrl-Space on other platforms. Code assist also shows up automatically after you type a period after “acre”.
• improved app selection menu: makes it easier to move from one app to another with the list of most recently used apps.
• console goodies: the log console now has a link to the source code of the page being executed and a breakdown of the ‘costs’ of executing the request (useful for profiling).
• no more extra blank lines inserted while cutting and pasting code inside app editor.
• files are now automatically saved when previewing.

NOTE: if you see some weird behavior of the app editor, try ’shift reload’-ing it as some browsers are pretty aggressive with caching parts of the application.

Engine

• allow ${} substitutions in <script> and <style> tags
• error pages have links back to the originating source line
• shift-reload now always returns fresh values

For more information on all the bugs fixed in this release, you can look at the issue tracker change log.

Happy Acre coding!