Moving an Xcode Project to MacRuby from Objective-C

Moving an Xcode project from Objective-C to MacRuby can be useful as a way to create a MacRuby example. The Xcode distribution, in particular, contains dozens of example projects which could serve as starting points. One might also wish to convert a real-world application in order to benefit from MacRuby's flexibility, assorted Ruby libraries, etc.

However, performing such a conversion in a single step is risky, because multiple translation errors may conspire to complicate debugging. Fortunately, it is possible to move projects in an incremental manner.

Preparation

• Make a copy of an existing project.

• Modify the copy to link against the MacRuby framework.
  • Copy in main.m from an existing MacRuby application (change).
  • Copy in rb_main.rb from an existing MacRuby application (addition).

• Add a build phase that copies *.rb into the Resource directory of the application bundle.

• Try out the copied project, to make sure it still runs properly.

Coding Changes

• Convert a file from Objective-C to MacRuby.
  • Create SomeClass.rb, corresponding to SomeClass.[mh].
  • In SomeClass.rb, define a replacement method (and class, if need be).
  • Comment out the Objective-C method.
  • Try out the new method, to make sure it still runs properly.

• Once an Objective-C file contains only comments, it can be removed.