Add setting for category support

[xtaria]

Under "Create the Static Library Target", I added Step 6 to include support for Objective C Categories

[wilmarvh]

This saved me, thanks.

+1 for merge

[jomisj]

Helped me. Thanks

[jverkoey]

Will merge if we can get some clarification on the problem this addresses.

[jomisj]

Here is a detailed explanation of the issue:

Lets say, I have created a category for a class (say, NSString) in my framework project and made it a public header. The user won’t be able to use the category methods unless the build setting of Framework project is changed as @xtaria has mentioned. Without these build settings, the app crashes saying unknown selector for NSString.

My case a bit more different:
In my case, I had the OAuth2Client project added as a subproject of my framework project. But the Third Party app using my library/framework was crashing when my library tried to call any category methods.

More specifically, my third party app was crashing saying unknown selector in NSURL because my library was calling a method in NSURL+NXOAuth2.

So I had to change the OAuth2Client’s (subproject of my framework) build setting (“Perform Single-Object” to YES).

[jverkoey]

Is this addressable by using the category fix approach?

https://github.com/NimbusKit/basics/blob/master/README.md#avoid-requiring-the--all_load-and--force_load-flags

[jverkoey]

I'm asking because I want to minimize the number of non-default flags encouraged by this guide. Solutions in code are preferred because they solve the same problem in more situations.

[jomisj]

I tested solution mentioned in NimbusKitBasics. But it did not solve the issue at hand.