I am trying to share some code between an app and an extension, using a framework. Mostly this works, but I have several categories that do not seem to load correctly in the extension. For example, I have a category on NSString to reverse the target string, but when I try to use that selector within the extension my code traps with an "unrecognized selector" exception. I tried adding the "-all_load" linker flag, first to just the framework, and then to the extension, to try and force load all the classes implemented in the framework, but this does not seem to work.
Any suggestions would be most welcome...
-David
If I remember correctly you need to set -ObjC in other linker flags in the parent project that is using your library/framework. The -all_load was being used to fix a bug in the -ObjC one, this is not needed anymore.
Related
I added the Parse SDK today (1.2.15) to an existing project which targets iOS7 and is built in Xcode5. I followed the instructions on https://parse.com/apps/quickstart#ios/native/existing exactly. Some things work, like creating and saving a PFObject. Certain functions however cannot be found by the compiler. For instance [PFUser enableAutomaticUser]; generates the error
AppDelegate.m:21:13: No known class method for selector 'enableAutomaticUser'
and [PFAnalytics trackAppOpenedWithLaunchOptions:launchOptions]; generates the error
AppDelegate.m:20:6: Use of undeclared identifier 'PFAnalytics'
Are the docs out of date and have these methods moved? I have tried restarting Xcode and cleaning my project. I can see the PFAnalytics.h file if I expand Parse.Framework in Xcode, and when I look at PFUser.h I can see a declaration of enableAutomaticUser;. Why can Xcode see some Parse classes and methods but not others?
My problem was that Framework Search Paths in Build Settings contained two directories, and one was invalid, resulting in this very strange behavior where some methods in Parse worked and others didn't.
I am having the error and it is AdMob crashes with [GADObjectPrivate changeState:]: unrecognized selector.
I know I need to add -objC but if I add, the following consequences occur.
Consequence
I am using Parse SDK and now I don't need to add facebook SDK (because I don't use -objC).
If I add facebook SDK, there are many other problems occur and it might need not to support iphone 3gs, 4,etc.
As a result, I need to know a way to solve this problem without adding -objC and also -all_load. I would like to know how to do.
I have found out a way to do.
Instead of using -objC, I can set to the required library only by using this.
-force_load <library file name>
So, -objC isn't required.
I am using some third party software to aid in writing an iPad application using Xcode 4.3.2. The software is open source and is usually set up so its code will be compiled along with whatever code the developer writes for the application. Because I was using the software in numerous places, I decided to build it as a static library for the iOS simulator.
I was able to build the library, and convert one application to link to that library instead of compiling the original source code. However, when I go to run the application on the simulator, I get an error that says, unrecognized selector sent to instance.
I have verified that the program is successfully using portions of the static library. However, there is one piece of code that tries to call a method on an object, and that where the failure occurs. The method being called is not actually defined in the interface of that object. Rather it is provided in an additional module that defines a category for that object's class. The header file for that module is properly included and the compiler should have been able to find the category method and apply it to the object, yet at run time, the error mentioned above occurs.
I used the 'nm' command to verify that the category method exists in the static library. Here is an example of the output:
nm libStaticLibrary.a | grep categoryMethod
00000130 t -[SomeClass(Category) categoryMethod:]
0000354c s -[SomeClass(Category) categoryMethod:].eh
What ideas do people have about how this library can be made to work correctly with the desired application?
Your 3rd party framework is probable using a category on a existing (apple) class. But to load/find the category you need to add the -ObjC flag in the build settings under Other Linker Flags
Pfitz answer is great, but this will cause the compiler to load a bunch of unused binaries to your project which is not what you want. Please refer to this answer to know why https://stackoverflow.com/a/22264650/1363997
Here is the best solution:
1) select your project target from the left panel (the folders navigator)
2) select "Build Phases" tap
3) expand "Compile Sources" cell
4) hit the plus button at the bottom and then add your category's .m file
Done!
Note: you have to search for the file by navigating through the folder by your self, don't type the file's name in the search field
I have two projects which the RestKit framework.
One project works without problems but another project fails, as soon as the RestKit framework is used.
I found out that the failing code is this:
return [anNSString MD5];
The MD5 method is a category method and is imported like this:
#import "NSString+MD5.h"
However, in one project, I keep getting the following error:
-[__NSCFString MD5]: unrecognized selector sent to instance 0x88a3390
I understand the basics of categories, and that they can be loaded at runtime, but I don't see why the category does not get loaded in this case.
These are the files on github: NSString+MD5.m, NSString+MD5.h,
Make sure you have the -ObjC flag enabled. Or it will not link categories in a static library.
Objective-C categories in static library
It's not enough to just include the header file. You also need to compile and link the .m file in your project.
I've added Box2D to a Cocos2D project I'm working on.
I've followed several guides as to how to do this (all of which seem to differ!).
However, none seem to work.
I'm getting these types of errors:
error: Box2D/Collision/b2BroadPhase.h: No such file or directory
I assumed I'd got the Header Search Paths wrong but have tried all sorts of variants with no luck.
Any suggestions?
The easiest way to use Box2d with your project is to follow these lines:
Copy the Box2d files into a subfolder of your project.
Import these files into your project via Xcode.
After in the "Project navigator", select your target and open the “Build Settings” tab.
Set the "Always Search User Paths" to YES.
Then search for the "User Header Search Path" and add this "${PROJECT_DIR}" (think to check the “recursive path“).
That's all!
You just have to be careful when you want to use Box2d. Think to change the extension of your files from .m to .mm to warn the compiler that the class must be compile as Objective-C++ instead of Objective-C.
I have found a good tutorial here (with Xcode 3.2, but the idea is here). I hope it'll help you.
Alternatively ... After a lot of trouble trying to include box2d in my project, I instead used box2d as a static library - takes a minute to setup, but it's much easier to maintain / add to multiple projects. Step by step guide here:
http://red-glasses.com/index.php/tutorials/box2d-for-ios-made-easy-make-it-a-static-library/