I also added some code that creates some actual entities. Doing this I ran into some other problem that made me wonder if you know how to sort that.

If I run the CDPlugins application the first time without the plugin and create a Person entity everything is fine and gets successfully saved to the store.

Adding the plugin to the application support folder and launching the application again results in the following error message when trying to save a Widget entity to the store.

‘The managed object model version used to open the persistent store is incompatible with the one that was used to create the persistent store.’

The updated source can be found at: http://dl.dropbox.com/u/706599/CDPlugins.zip

Now I’m seeing what you’re saying. I’ll have to experiment with this when I have some down-time. I’m going into beta-test mode with some folks, and I think now’s not the time to be mucking around. :-)

I’ll let you know what comes of my travails.

-g

When you say “just share it” with respect to models between two projects, I’m not sure I understand what that means or how to do it. How does this work?

Sorry for the neophyte-like questions. I’m good at some stuff, but I’m just not quite groking what you’re saying.

In the meantime, I’ll try Google for a thousand dollars…. ;-) Maybe I’ll get a burst of enlightenment.

-greg

Second, this article was designed for the desktop.

Third, if you need to share a model between two projects, just share it. Multiple Xcode projects can reference the same file with no ill effect.

Neither way produced the expected results.

Any ideas? I really want to get this to work, as this technique will save me an enormous amount of potential heart-ache. I’ve got a huge CD data model, and need to use it in two different apps. If I can get this to work, then I don’t have to keep copying changes over from one to the other!

Also. I’m thinking this through, and I don’t quite see how this will work for Cocoa Touch apps. Am I supposed to drop the plugin into one of the sub-folders under “iPhone Simulator”?

Sorry if I’m being dense about this. I’m definitely in new territory, here.

-greg

Do you have any posts/articles that dig further into plugins themselves? In briefly reading through this, it looks like you might be talking about static frameworks, but I haven’t read closely enough to be sure. If you have any more detailed discussions (or can point me towards someone who does), I’d love a link.

Quick aside–I live in the Baltimore area, and there’s an Airline (AirTran?) that is running a series of commercials related to the Baltimore Ravens. One of them features a rather … intense … individual who knows trivia down to the minute detail on his fantasy football players. His friend suggests he needs a girlfriend. He responds (maybe a slight paraphrase): “Fantasy football is my girlfriend.”

Thought you’d appreciate it. ;-)

-greg

I tried making a duplicate abstract entity in the second core data model, but it still crashed complaining of duplicate entities. Without the duplicate, there seems to be no way to tell core data that the entity is actually a subentity of an entity in a different file.

The next step would be to add support for document-based Core Data apps. Storing one additional file for each plug-in would be slightly impractical for end users. One would probably want to place all files together in a bundle instead.

Before reading this article I would have said that extra plug-in storage in a document-based Core Data app is incredibly difficult. Now it just seems like a lot of hard work!