Cocoon Updated for Windows 8 Release Preview

You will be pleased to hear that I have just pushed an updated version of the Cocoon framework onto CodePlex that supports the Windows 8 Release Preview.

As usual the code is freely available for download from the Cocoon CodePlex site (to get the latest version go to the “Source Code” tab, select the first change set and use the “Download” link).

Using MEF in the Release Preview

As many of you will be aware, the Cocoon framework uses the Managed Extensibility Framework (MEF) by default for locating and composing applications. With the release of the Windows 8 Release Preview, MEF is not being distributed separately – for more details see the announcement on the BCL team blog.

You will therefore need to add MEF as a reference to your application via NuGet. The above link has more details however the steps are,

1. Right click on your projects ‘References’ folder and select “Manage NuGet Packages…”
2. Select “Online” in the left-hand pane and make sure that you have “Include Prerelease” selected rather then “Stable Only” at the top.
3. Use the search box to search for “MEF”
4. Select “MEF for web and Metro style apps” and click “Install”

Changes in tHis Release of Cocoon

In general most applications should not be affected by the changes in this version of Cocoon (apart for the fact that they will run on the Release Preview!). Changes of interest include,

• All use of MEF has been modified to support the new version
• The ‘CocoonBootstrapper’ no longer has an overridable GetPartCatalog() method and is replaced with GetContainerConfiguration().
• The ISupportPlaceholder interface has been removed in the Release Preview. The VirtualizingVector<T> implementation has been updated to reflect these changes and now returns ‘null’ as a placeholder (as now expected by the standard XAML controls).
• Many other updates and bug fixes