How not to link a framework in iPhone dev


With much help from Erik, the owner of OCMock, I discovered how much of a loon I can be. Let me set the stage with a story, like I typically do on this site. You’re writing unit tests for a spankin’ new iPhone project that’s gonna shake the world if it ever releases. You’ve got backing suport from everybody from MGM Studios to Barack Obama helping you to make your release date. You are an advocate of all things Agile, TDD, and behavior driven. You absolutely cannot fail! You now need to do something clever in your unit tests. Something Apple doesn’t provide facilities for. You find a framework that does it. Maybe you’re bringing in OCMock or maybe you’re just trying to link Hamcrest. Hi, I’m Cliff. You’re here because your framework won’t load in your unit tests. I’m here to tell you how not to link against it.

Many years ago (like 1), I tried to link against OCMock. The only way to make it work was to drop it into the magic place called “/Library/Frameworks/”. It worked. It worked well. It worked so well that I decided to become the OCMock super hero. I wrote a blog about it. (Like to hear it? Here it go!) I wrote an OCMock setup thing with Automator/AppleScript for other developers that weren’t as John Blazed as I was so that they too could enjoy the beauty that was OCMock. (Just had a flashback to the little stored procedure runner tool I wrote when I was being the VB6-toRPGIV super hero many more years ago.) Here’s where a super hero becomes a super zero.

I neglected the principles of software development. Anything that goes in a System folder is visible to everything. Putting files, tools, trinkets there are always error prone, remedies for disaster. Why? Because it’s fire and forget… A one time setup that you never need to worry about. The forget part of the fire is what bites. The one time step that you always need to think about when troubleshooting but never do. Like I said, a year passes and I haven’t done much with OCMock except for occasions. Now I wanna upgrade to the latest version. I’ve since learned a better way to link projects to frameworks but my machine still “remembers” the old way. My new process, from memory, goes something like:

  • Find a framework
  • Drag/drop it into your project
  • Do something in the build configs, like setting a framework search path
  • I think that’s it, right? Yeah. Compile and run and I see the green button. I’m good!

Everything works as expected. I’m pretty sure I’m picking up the right version because I just double clicked the little framework icon and triple checked the path pointing to the newly downloaded folder. I could go the extra mile and look for the notes I wrote last year and make sure there’s no other gotcha’s but things are working. Why bother?

There’s two critical problems here. the first is that I never removed the frameworks from the magic “fire and forget” place. Just don’t put things here and you’ll never have to remember to delete them when you upgrade or when they break other things. The second problem is that I didn’t remember my new method for linking because my machine still remembered the old way making me feel like I was all good. The better way to link frameworks in iPhone dev is to put a “copy files” build phase into your target, set the destination path to “products directory” and drag/drop your frameworks into this phase. One caution is that while you can run on the Mac using the Simulator you still can’t load frameworks on the device. So I conclude this long winded article that could have been summarized in 2-3 sentences by saying, if you wanna suck at programming overload your system folders with development frameworks and libraries. Not only will you immediately solve the problem at hand and meet your immediate deadline but you’ll break the next twelve identical problems in the future and miss all of those deadlines. Good luck making up weeks of productivity lost chasing a problem that only exists on your machine. Good luck making up several more weeks of lost productivity while you reinstall your OS and lose several other important files/temporary projects trying to fix the problem that only happens on your machine.

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