DevForce Community Forum : Get access to the MEF catalog http://www.ideablade.com/forum/ This is an XML content feed of; DevForce Community Forum : Community Forum : Get access to the MEF catalog Fri, 10 Apr 2026 19:12:03 -700 Tue, 20 May 2014 12:04:13 -700 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 9.69 360 www.ideablade.com/forum/RSS_post_feed.asp?TID=4699 DevForce Community Forum http://www.ideablade.com/forum/forum_images/IdeaBlade_logo_tm.png http://www.ideablade.com/forum/ Get access to the MEF catalog : As with every dependency, you... http://www.ideablade.com/forum/forum_posts.asp?TID=4699&PID=17551#17551 Author: mgood
Subject: 4699
Posted: 20-May-2014 at 12:04pm

As with every dependency, you just need to make the catalog available through MEF so you can inject it where you need it. Here's how you can accomplish this.

    public class AppBootstrapper : CocktailMefBootstrapper<MainViewModel>
    {
        private ComposablePartCatalog _catalog;

        protected override ComposablePartCatalog PrepareCompositionCatalog()
        {
            // Hang on to the catalog
            return _catalog = base.PrepareCompositionCatalog();
        }

        protected override void PrepareCompositionContainer(CompositionBatch batch)
        {
            base.PrepareCompositionContainer(batch);

            // Add catalog to the MEF container
            batch.AddExportedValue(_catalog);
        }
    }

    [Export]
    public class MainViewModel : Screen
    {
        [ImportingConstructor]
        public MainViewModel(ComposablePartCatalog catalog)
        {
            
        }
    }
]]> Tue, 20 May 2014 12:04:13 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=4699&PID=17551#17551 Get access to the MEF catalog : Hi,I have a scenario with cocktail... http://www.ideablade.com/forum/forum_posts.asp?TID=4699&PID=17550#17550 Author: kdev
Subject: 4699
Posted: 07-May-2014 at 7:52am

Hi,

I have a scenario with cocktail where I need to get access to the Mef Catalog to query the Part property (http://stackoverflow.com/questions/23497474/how-to-know-the-original-type-of-a-class-exported-as-an-interface-in-mef).

I need this information to implement the TargetGuard method of the INavigator. I check if an attribute decorate (or not) the class to allow (or refuse) the navigation.

I understand why it's not possible to publish this property as it's MEF dependant and the ICompositionProvider is "universal" for all type of IoC. But it's in some case really annoying to not have access to the catalog.
I also know I could write my own implementation of MEF and give it to cocktail but it looks it's a lot of work (need to redo the bootstrapper too) for just a small thing (in my point of view).

Could it be possible to add a class (dedicated to MEF) on Cocktail which, like EntityAspect.Wrap(), could wrap the cocktail MEF implementation and publish the Catalog ?

Right now I have a workaround but it's far to be clean. in the TargetGuard method, I create a new AggregateCatalog and fill it with the loaded assemblies. It would be nicer to use the catalog present in Cocktail



Edited by kdev - 07-May-2014 at 7:55am]]> Wed, 07 May 2014 07:52:00 -700 http://www.ideablade.com/forum/forum_posts.asp?TID=4699&PID=17550#17550