Checking if code is running in Interface Builder

Question

I have custom IBDesignable classes in swift that do some things that cause crashes in Interface Builder. Is there a flag I can check to see if I'm running in interface builder or not? Ideally it would be a precompiler directive (#ifdef COMPILED_FOR_INTERFACE_BUILDER or something like that). I thought maybe I could set a flag myself in prepareForInterfaceBuilder() but that seems messy and doesn't seem to work reliably as it looks class properties are set before that function is called and this can trigger code that causes problems. Seems like there must be a better way. Thanks!

Ashmead

Don't know why this question was voted down. I think it's a great question. (Of course I have no useful answer...) – Knapsack

I agree. This would be a very useful feature. (Voted) – Whoso

Answer 1

From https://developer.apple.com/library/ios/recipes/xcode_help-IB_objects_media/Chapters/CreatingaLiveViewofaCustomObject.html:

You can use the preprocessor macro TARGET_INTERFACE_BUILDER to specify code for inclusion with or exclusion from your custom view class."

Chlorinate

Thanks! This was exactly what I was looking for and for some reason no amount of googling turned up that macro. Very useful! – Ashmead

10/10 this is exactly what I needed! – Musing

Wow, this is going to change my whole life dealing with IB crashes! Thank you x 1000! – Farver

Thank you @EwanMellor, this made my day!! – Calculated