[CubeWannaB]

40 minutes of searching the xcode documentation hasn't yielded an answer:

I'm wondering how to register my App to open certain filetypes, and how to get a list of applications that will open a given filetype.

Related, I'm wondering how to find out what the proper name for a filetype is?

[Chuckit]

Originally posted by CubeWannaB:
40 minutes of searching the xcode documentation hasn't yielded an answer:

I'm wondering how to register my App to open certain filetypes

It's in there under Document-Based Applications for Cocoa. Since you don't specify all that much, I'll just leave it there and assume that's what you're doing.

and how to get a list of applications that will open a given filetype.

The LaunchServices function LSCopyApplicationsURLsForURL() can do this, though it's Panther-only. I think otherwise you'll have to just get the application list and ask if they can open a given file one-by-one. I haven't looked extensively, but I don't know how else you'd do it.

Related, I'm wondering how to find out what the proper name for a filetype is?

I do not believe there is a system-defined "proper name for a filetype." Ask whoever created the filetype.