I'm trying to use Novocaine in an iPhone application I'm building. I can't figure out how to get around this error I'm getting:
Unknown type name 'RingBuffer'
Here's my file structure:
...with those files under Novocaine being the ones pulled from the Github repo for Novocaine. Here's my header file for DDViewController.
#import <UIKit/UIKit.h>
#import <QuartzCore/QuartzCore.h>
#import "UICoordButton.h"
#import "Novocaine.h"
#import "RingBuffer.h"
#import "AudioFileReader.h"
#import "AudioFileWriter.h"
#interface DDViewController : UIViewController
{
RingBuffer *ringBuffer;
Novocaine *audioManager;
AudioFileReader *fileReader;
AudioFileWriter *fileWriter;
}
- (IBAction)changeColor:(id)sender;
- (IBAction)changeColor2:(id)sender;
#end
I've tried a solution that I found on another question, which suggests that this should work:
#class RingBuffer;
#interface DDViewController : UIViewController
{
...
But that just gives me Redefinition of 'RingBuffer' as a different kind of symbol.
How can I fix this problem and use RingBuffer?
RingBuffer is a C++ class. I recommend you change the extension of your Objective-C files from .m to .mm which will make them Objective-C++
Found the answer (or I guess a combination of answers):
Follow coryalder's advice for setting the compiler default to Objective-C++ as described here.
Also, change all .m files to .mm files, and finally add -fno-objc-arc compiler flags to all the .mm files -- which is described in detail here.
Related
I am creating Swift framework in which I have to use Objective-C class. So I went through this link. This is the public header of my framework :
#import <UIKit/UIKit.h>
//! Project version number for Test.
FOUNDATION_EXPORT double TestVersionNumber;
//! Project version string for Test.
FOUNDATION_EXPORT const unsigned char TestVersionString[];
// In this header, you should import all the public headers of your framework using statements like #import <Test/PublicHeader.h>
#import <arpa/inet.h>
#import <ifaddrs.h>
#import <netdb.h>
#import <sys/socket.h>
#import <MyTest/MPAppDelegateProxy.h>
Now in class MPAppDelegateProxy, I have to use a Swift class which I have created. This is :
#import "MPAppDelegateProxy.h"
#import "MyTest.h"
#implementation MPAppDelegateProxy
+ (void)proxyAppDelegate {
[MPGlobal MPLog:#"App delegate not set, unable to perform automatic setup." file:#"MPAppDelegateProxy.m" function:#"proxyAppDelegate" line:32];
// rest of code
}
MPGlobal is one of my Swift class. But I am getting :
Use of undeclared identifier 'MPGlobal'
Note : I have added #objC before MPGlobal.
You need to import <Target>-Swift.h file.
This is known as Objective-C Generated Interface Header Name.
You can find it in your Target's build settings.
This file is auto generated by compiler and it needs to be imported in Objective-C files.
change the SWIFT_OBJC_INTERFACE_HEADER_NAME build setting and making it the same across different targets. To do so change the instruction that generates this property from $(SWIFT_MODULE_NAME)-Swift.h to $(PROJECT_NAME)-Swift.h as explained here
After doing this Clean Build Folder by pressing Alt and going into Product menu. Since name of header is shared among targets now it can be imported once in the .m ObjectiveC file and all targets can benefit from Swift classes.
If after building it still shows the error, ensure that the header can be reached from XCode by Cmd clicking on its name. It should open a file that contains code similar to this:
SWIFT_CLASS("_TtC27ProjectName_Summary11MyClass")
#interface MyClass : NSObject
- (nonnull instancetype)init OBJC_DESIGNATED_INITIALIZER;
#end
If need to ensure that those headers are being generated open a terminal and use this command
find ~/Library/Developer/Xcode/DerivedData -name "*Swift.h"
You should see one header for each target
Another issue that happened to me after those changes is that it started giving errors on ObjectiveC code that I didn't touch. The problem was due to the position of the import, as reported here:
Exactly where at the top of a .m file you #import the hidden bridging
header can make a difference. The usual sign of trouble is that you
get an “Unknown type name” compile error, where the unknown type is a
class declared in Objective-C. The solution is to #import the .h file
containing the declaration for the unknown type in your Objective-C
files as well, before you #import the hidden bridging header. Having
to do this can be an annoyance, especially if the Objective-C file in
question has no need to know about this class, but it resolves the
issue and allows compilation to proceed.
At the very end the code compiles and runs on device and simulator!
Original answer
Also you can try this,
You needed to import the -Swift.h for for both the framework and the app target
For Example :
#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h>
#import <Foundation/Foundation.h>
#import "XLPagerTabStrip-Swift.h"
#import "RealmSwift-Swift.h"
...... // Add all frameworks, subclasses, and dependance ios frameworks
#import "MyProject-Swift.h"
You can read this article How to import file header and check paths
I have a new Swift project with a few files, I've needed to add some Objc code.
In Build Settings, my Objective-C Generated Interface Header Name is MyProject-Swift.h
Product Module Name and Product Name are both MyProject.
My Objective-C Bridging Header is MyProject/MyProject-Bridging-Header.h
The contents of my Bridging Header are:
#ifndef MyProject_Bridging_Header_h
#define MyProject_Bridging_Header_h
#import "Blakey.h"
#endif
Blakey.h is pretty simple:
#import Foundation;
#import "MyProject-Swift.h"
#class KeyPair;
#interface Blakey: NSObject
- (void)createKeyPairForSeed:(NSString *)seed;
#end
And Blakey.m
#import <Foundation/Foundation.h>
#import "Blakey.h"
#implementation Blakey
- (void)createKeyPairForSeed:(NSString *)seed;
{
}
#end
(side note: I'm aware my function returns a void, that will be changed later once this issue is fixed so it returns an actual value)
Why is Xcode throwing an error at the #import "MyProject-Swift.h" in Blakey.h?
Project-Swift.h is a file auto generated by Xcode on successful compilation of the project. Catch here is the word successful compilation If your project has any compilation error Project-Swift.h file will not be generated. So in a way it becomes a deadlock. Bestway comment out all the lines that have compilation error and then manage to get it compile without any errors. Only after that Project-Swift.h will be generated.
Additional information, Once the Project-Swift.h file is generated if you open it and if you happened to see that your swift class is not imported there thats because Project-Swift.h imports only the classes that extends from NSObject So plain Swift classes will not be imported.
ISSUE:
You need to import Project-Swift.h in .m file and not .h file. So modify your Blakey as
#import <Foundation/Foundation.h>
#import "Blakey.h"
#import "MyProject-Swift.h"
#implementation Blakey
- (void)createKeyPairForSeed:(NSString *)seed;
{
}
Finally remove #import "MyProject-Swift.h" from Blakey.h
#import Foundation;
#class KeyPair;
#interface Blakey: NSObject
- (void)createKeyPairForSeed:(NSString *)seed;
#end
I had similar issue and almost ended up spending a whole day trying to figure out what wrong with my app.
So following the solution that's helped me :
Clear derived data
Create a class in swift with prefix of #objc for example #objc class mySwiftClass{...}
Build the project again
Et voila.. Should work now.
Why to add #objc?
this #objc prefix, tells the compiler to generate to your swift class a header file. it will add it to the "MyModule-Swift.h" file
I realize this is an old thread, but I had similar issues after adding a new target to a project. I solved it by adding a preprocessor macro (Build Settings -> Apple Clang - Preprocessing) only in said target and then importing the Swift.h file conditionally, like this:
#if DEV_VERSION
#import "Project_DEV-Swift.h"
#else
#import "Project-Swift.h"
#endif
My main target is called Project and the new target is Project DEV (the space is replaced with an underscore in the import), and the preprocessor macro is called DEV_VERSION.
After doing this, both targets build just fine.
<product_name>-Swift.h file not found
It is a kind of bridge(adapter) between Swift and Objective-C. This file contains Swift's API for Objective-C which was marked [#objc and #objcMembers].
You can work with types declared in Swift from within the Objective-C code in your project by importing an Xcode-generated header file.
The header's name is generated from a <product_name>-Swift.h
[Mixing Objective-C and Swift ]
I had a similar issue whereby it would have this issue for anything other than live.
I resolved the issue by hardcoding "Product module name" & "Product name" to my project name. This avoids the need to have preprocessor logic in every file that includes swift code as demonstrated in Pauli Kettunen's solution.
I want to import files from this library, I copied and pasted the following .h and .m files from the ObjC library into my Swift project:
AppDelegate.h AppDelegate.m
ViewController.h ViewController.m
SPUserResizableView.h SPUserResizableView.m
Upon copying and pasting these files into my project, Xcode asked me to create a bridging header file, I then put the following lines into that bridging header file:
#import "ViewController.h"
#import "SPUserResizableView.h"
#import "AppDelegate.h"
#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
I tried to build my project, but build failed. I got many unknown type errors and such, which I assume is because the system is not recognizing the ObjC code. I also got this line of error:
failed to emit precompiled header '....../Project-Bridging-Header-swift_24D19ORYKRN0-clang_1KQCLSEAC5RDY.pch' for bridging header '......./Project-Bridging-Header.h'
How do I resolve these errors? What else do I need to do to use the Objective C library in my swift code?
Why you import AppDelegate.h and other
just use this class (SPUserResizableView.h SPUserResizableView.m)
and in Bridge file
^ #import "SPUserResizableView"
in your BridgingHeader just add
#import "SPUserResizableView.h"
dont copy other projects AppDelegate and ViewController. just copy SPUserResizeableView.h and .m file
I am writing a few XCTests for an app. When I just start editing the AppTests.m, I get an error saying it can't find ZeroPush (which is in AppDelegate.h):
Lexical or Preprocessor Issue
/Users/jt/repos/clients/App/App/AppDelegate.h:10:9: 'ZeroPush.h' file not found
but when compiling my app normally, it is able to find it. In my ViewController, it is able to find AFNetworking. How would I fix this?
my AppTests.m
#import <XCTest/XCTest.h>
#import "AppDelegate.h" // <- this imports ZeroPush.h
#import "ViewController.h"
#interface AocWineBarTests : XCTestCase{
#private
UIApplication *app;
ViewController *viewController;
AppDelegate *appDelegate;
//CalcViewController *calcViewController;
//NSView *calcView;
}
#end
In your app delegate, change:
#import "ZeroPush.h"
to
#import <ZeroPush/ZeroPush.h>
I'm making an assumption that the folder it's in is named ZeroPush. Change the folder path to whatever the real path needs to be.
I'm setting up a base view controller called "BHAccountBaseViewController" and two other views that inherit from some basic functionality from the base controller.
"BHAccountBaseViewController" Inherits from "UIViewController"
"BHAccountViewController" (implements UITextFieldDelegate) and Inherits from "BHAccountBaseViewController"
Lastly I have one recently created class that I called "BHCreateProfileViewController" every time that I just simply include #import directive to "BHAccountBaseViewController" to inherit from this class Xcode fails to compile due to APPLE MACH-O LINKER ERROR!
clang: error: linker command failed with exit code 1 (use -v to see invocation)
Thoughts? these are my three header files
BHAccountBaseViewController
#import <UIKit/UIKit.h>
#import "BHFileManager.h"
#interface BHAccountBaseViewController : UIViewController
#end
BHAccountViewController
#import "BHAccountBaseViewController.h"
#interface BHAccountViewController : BHAccountBaseViewController<UITextFieldDelegate>
#end
BHCreateProfileViewController
#import "BHAccountBaseViewController.m"
#interface BHCreateProfileViewController : UIViewController <UITextFieldDelegate>
#property (strong, nonatomic) id user;
#end
if I comment out the import on the last file the linker error goes a way! but I want to be able to inherit from my base clase ... thoughts?
Help would be much appreciated!
In implementation of BHCreateProfileViewController given above, I found the code looks like getting wrong at first line. What about fixing it as following:
#import "BHAccountBaseViewController.m"
to
#import "BHAccountBaseViewController.h"
and I wonder why BHCreateProfileViewController comes to inherit from UIViewController not BHAccountBaseViewController. Could you explain that?
This might be due to the retain cycle deadlock problem. You have to use forward class declaration for this i.e you can try #Class instead of #import. Please refer to these limks :
Objective-C: Forward Class Declaration
#class vs. #import
These might help.
In the compilation time your compiler would actually look for your interface files instead of implementation file.Compiler does not bother even if .m file is not available. So while importing you are supposed to import .h instead .m.