Eli Robillard's World of Blog.

Extending SharePoint 2010 tooling in Visual Studio 2010

Extensibility points

• Already had: Macros, add-ins and packages
• New extensions based on MEF
• VSIX model simplifies distribution and deployment

VSIX Package

• A zip package
• Contains am .XML manifest
• Install by double-clicking

Managed Extensibility Framework (MEF)

• Part of .NET 4.0
• An extensible app "imports" functionality
• An extensible componet "exports" its functionality
• An application catalog tracks instances of imported component
• An application is composed by dynamically loading components

SharePoint Tools export extensibility interfaces

• The interfaces: ISharePointProjectExtension, IProjectItemExtension, IDeploymentStep, IExplorerNodeTypeExtension (though these may change for beta 2 release)
• Your custom extensions export these interfaces, e.g. :

[Export(typeof(ISharePointProjectExtension))] 
internal class myClass : ISharePointProjectExtension {
     public void Initialize(...)
    
     /* add event handlers */
    
     void projectService_ProjectMenuItemsRequested(...) {
          /* Add your options to the project menu */
     }
}

• Requires applying MEF attributes to export each interface
• MEF attributes written to the catalog at installation

Calls to SharePoint

• The trick is that VS is 32-bit and SharePoint is 64-bit, so if you want VS to execute SharePoint operations, you need to use a special SharePointCommand type that will marshal the code for you for execution in a 64-bit thread. The Client OM would be a simpler option if you don't need to elevate permissions.

 Designers

• You can build WPF extensions to VS2010 and there will be a number of community projects that do exactly that, or provide templates for custom designers.

* Notes from a SharePoint Conference 2009 (#spc09) presentation by Ted Pattison and John Flanders.