Question

I have a custom module. Migrations.cs looks like this.

    public int Create()
    {
        SchemaBuilder.CreateTable("MyModuleRecord", table => table
            .ContentPartRecord()
            ...
        );

        ContentDefinitionManager.AlterPartDefinition(
            typeof(MyModulePart).Name, cfg => cfg.Attachable());

        ContentDefinitionManager.AlterTypeDefinition("MyModule",
           cfg => cfg
                .WithPart("MyModulePart")
                .WithPart("CommonPart")
                .Creatable()
            );

        return 1;
    }

This is the code I have in the controller.

  var newcontent = _orchardServices.ContentManager.New<MyModulePart>("MyModule");
  ...
  _orchardServices.ContentManager.Create(newcontent);

I get the invalid cast error from this New method in Orchard.ContentManagement ContentCreateExtensions.

    public static T New<T>(this IContentManager manager, string contentType) where T : class, IContent {
        var contentItem = manager.New(contentType);
        if (contentItem == null)
            return null;

        var part = contentItem.Get<T>();
        if (part == null)
            throw new InvalidCastException();

        return part;
    }

Any idea what I am doing wrong?

Thanks.

This is the handler.

public class MyModuleHandler : ContentHandler
{
    public MyModuleHandler(IRepository<MyModuleRecord> repository)
    {
        Filters.Add(StorageFilter.For(repository));
    }
}

Answer 1

You are getting the InvalidCastException because the content item doesn’t appear to have your MyModulePart attached.

If there were a driver for your part, then there is an implicit link somewhere that allows your part to be shown on a content item (I’m not sure how this is done, maybe someone else could elaborate – but it is something to do with how shapes are harvested and picked up by the shape table deep down in Orchard’s core).

However since you don’t have a driver, adding an ActivatingFilter to your part’s handler class will make the link explicitly:

public MyModulePartHandler : ContentHandler {
    public MyModulePartHandler() {
        Filters.Add(StorageFilter.For(repository));
        Filters.Add(new ActivatingFilter<MyModulePart>("MyModule");
    }
}