I just started porting an Android app to iOS, and am hitting a major roadblock that I can't figure out despite scouring many similar questions.
I am attempting to follow the pattern implemented in the CastVideos sample where the GoogleCast API is encapsulated in a singleton class which I've called CastManager. To use my singleton class, I #import "CastManager.h" in AppDelegate.m. Then in CastManager.h, I #import <GoogleCast/GoogleCast.h> so that I can use classes and protocols from it as part of CastManager's public interface. However, because I'm importing CastManager.h in both CastManager.m and AppDelegate.m, the linker is finding duplicate symbols from the GoogleCast framework.
This is my CastManager.h:
#import <GoogleCast/GoogleCast.h>
#import <Foundation/Foundation.h>
#interface CastManager : NSObject
#property(nonatomic, strong) GCKDeviceScanner *deviceScanner;
+ (instancetype)sharedCastManager;
#end
And corresponding CastManager.m:
#import "CastManager.h"
#implementation CastManager
+ (instancetype)sharedCastManager {
NSLog(#"sharedCastManager");
static CastManager *singleton = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
singleton = [[self alloc] init];
});
return singleton;
}
- (instancetype)init {
NSLog(#"init()");
if (self = [super init]) {
self.deviceScanner = [[GCKDeviceScanner alloc] init];
}
return self;
}
#end
And this is the main part of my AppDelegate.m:
#import "AppDelegate.h"
#import "CastManager.h"
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
CastManager *castManager = [CastManager sharedCastManager];
return YES;
}
However, this results in the following error from the linker when attempting to build the project:
duplicate symbol _kGCKDeviceCapabilityVideoOut in:
/Users/nate/Library/Developer/Xcode/DerivedData/MyCastApp-ezrgxdnlvywpanerezulnarzknno/Build/Intermediates/MyCastApp.build/Debug-iphonesimulator/MyCastApp.build/Objects-normal/x86_64/AppDelegate.o
/Users/nate/Library/Developer/Xcode/DerivedData/MyCastApp-ezrgxdnlvywpanerezulnarzknno/Build/Intermediates/MyCastApp.build/Debug-iphonesimulator/MyCastApp.build/Objects-normal/x86_64/CastManager.o
... many similar errors ommitted for brevity ...
duplicate symbol _kGCKDeviceCapabilityAudioIn in:
/Users/nate/Library/Developer/Xcode/DerivedData/MyCastApp-ezrgxdnlvywpanerezulnarzknno/Build/Intermediates/MyCastApp.build/Debug-iphonesimulator/MyCastApp.build/Objects-normal/x86_64/AppDelegate.o
/Users/nate/Projects/MyCastApp/GoogleCast.framework/GoogleCast(GCKDevice.o)
ld: 8 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
As far as I can tell, this exactly copies the pattern as defined in the CastVideos sample, but the sample compiles fine, and mine doesn't, and I've scoured through both projects trying to find what is different, but I just don't see it. Further, I don't see anything really wrong with doing this, and would expect it to work fine. I can't think of any other way to do it, really.
Here are the relevant files from the CastVideos sample for comparison:
ChromecastDeviceController.h
ChromecastDeviceController.m
AppDelegate.m
Other questions point to solutions that don't apply or don't fix it:
I'm not importing a .m file on accident.
I don't have duplicate references to any files in the project.
The "Compile Sources" section of the "Build Phases" project setting doesn't include any duplicates.
I've added the '-ObjC' linker flag as described by the GoogleCast API docs, though it has the same error with or without it.
I've tried deleting the delegate data and doing a clean before building.
This is with Xcode 6.3.1 running on OS X Yosemite 10.10.3 and the GoogleCastSDK-2.6.0 package from the SDK documentation page
I have checked in my sample project with the problem at https://github.com/nshafer/MyCastApp
Any help is greatly appreciated!
Edit: the duplicate is somewhat related, it's definitely about the same symbols, but the answers there didn't help, as I'm not using Object-C++, but rather just Objective-C. I don't have a .mm file, just a .m file.
For me it helped to switch the "No Common Blocks" compiler setting to NO:
It pretty much seems to make sense, the setting is explained here: What is GCC_NO_COMMON_BLOCKS used for?
The linker tells you that you have a variable named kGCKDeviceCapabilityVideoOut in two files, AppDelegate.m and CastManager.m. Since it's not in your source code, it's most likely in the GoogleCast code that you are including.
Either change the GoogleCast.h file, or make sure it is only included in one .m file. Including it from CastManager.h means it is indirectly included in every file that includes CastManager.h, so I would avoid that and only include it from CastManager.m. You'll probably have to add
#class GCKDeviceScanner;
in your CastManager.h file.
I found another fix, which is to edit GCKDevice.h in the GoogleCast.framework/Headers folder. Change the 4 constants from GCK_EXPORT to GCK_EXTERN near the top of the file.
/** Device capability flag for video out. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityVideoOut;
/** Device capability flag for video in. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityVideoIn;
/** Device capability flag for audio out. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityAudioOut;
/** Device capability flag for audio in. */
GCK_EXTERN const NSInteger kGCKDeviceCapabilityAudioIn;
I detailed this in a bug report I filed with Google's issue tracker, but it was marked as a duplicate of another somewhat related issue. Either way, it will perhaps get fixed in the next version. Until then, I would suggest going with changing the "No Common Blocks" setting as detailed in Joobik'com's answer, as that doesn't involve changing the 3rd party code.
Related
I'm building a static library in iOS. after importing that library in my project, I added -ObjC in Other linker flags. But when I call the class methods(currently 3 available), 2 of them are being called and executed properly, but the last one is getting this error: "+[RankConferenceLib joinConferenceWithName:]: unrecognized selector sent to class 0x5044dc".
This is my Header file of library
#interface RankConferenceLib : NSObject
+(void)initEnvironment;
+(void)orientationChange;
+(void)joinConferenceWithName:(NSString *)name;
#end
in .m file of library
+ (void)joinConferenceWithName:(NSString *)name
{
//....codes
}
and in my project I'm calling them
- (IBAction)join:(UIButton *)sender {
[RankConferenceLib joinConferenceWithName:#"User"];
}
Please tell me what I'm missing here. This is my first static library. I've searched but could not find any help which is similar as my situation here. Please mention what else you need to know.
Thank you.
I have checked this and for me it's working fine without any linker flags added.
The only one error possibility is something happened inside the + (void)joinConferenceWithName:(NSString *)name
Write a log inside the joinConferenceWithName to printout the parameter name and make sure this is calling and the problem is occurring inside that method.
+ (void)joinConferenceWithName:(NSString *)name
{
NSLog(#"the name is: %#", name);
}
Finally, make sure that you added the latest modified static library into your project.
You can download the working sample from here
Try Running using the -all_load linker flag
Apple Documentation
Stack Overflow Answer
I'm getting this error:
/Class/GData/OAuth/GDataOAuthViewControllerTouch.m:116:22: Expected a type
That line is:
authentication:(GDataOAuthAuthentication *)auth
Inside of this block of code:
- (id)initWithScope:(NSString *)scope
language:(NSString *)language
requestTokenURL:(NSURL *)requestURL
authorizeTokenURL:(NSURL *)authorizeURL
accessTokenURL:(NSURL *)accessURL
authentication:(GDataOAuthAuthentication *)auth
appServiceName:(NSString *)keychainAppServiceName
delegate:(id)delegate
finishedSelector:(SEL)finishedSelector {
NSString *nibName = [[self class] authNibName];
I'm a newb XCode developer. So far I've created and compiled a calculator app based from an online class but that's it.
Is this a library that is not being included?
Background: The previous developer abandoned the project and the owner sent the project code to me. I'm trying to replace the existing graphics with new graphics and recompile it with support for iOS 6, which I thought I should be able to do without any coding, but have run into this error and many others when I opened the project. I have the latest XCode.
The :22 (and the position of the caret within the editor) tell you exactly where on the line the error is. In this case it's telling you that where it sees GDataOAuthAuthentication it was expecting a type. So, implicitly, it doesn't recognise that GDataOAuthAuthentication is a type.
Objective-C still sits upon compilation units ala C — each .m file is compiled in isolation then the lot are linked together. You use #import (or #include if you want; #import just guarantees the same file won't be included twice) to give each individual file visible sight of any external definitions it needs.
So, that's a long-winded way of reaching the same conclusion as Rick did five minutes ago: you've probably omitted a necessary #import.
A few things to look for:
Did you #import the file where the GDataOAuthAuthentication type is defined? (e.g. #import "GDataOAuthAuthentication.h")
Is there a variable named GDataOAuthAuthentication which is causing the compiler to think GDataOAuthAuthentication is a variable not a type?
I am getting this error for a single class from a static library, which I have compiled myself. It has all been working fine and I wanted to add another class as a simple data transfer object called PPClientData.
The error is:
Undefined symbols for architecture armv7:
"_OBJC_CLASS_$_PPClientData", reference from: objc-class-ref in
CPPIntegrationDelegate.o
The relevant file is included in the library compile targets and I have used otool -d on the (fat) library and it shows
libPPIntegration.a(PPClientData.o) (architecture armv7):
(__DATA,--data) section
The header for the class (PPClientData.h), which is included in the app is like this:
#import <Foundation/Foundation.h>
#interface PPClientData : NSObject
#property(nonatomic, strong) NSString* clientId;
// 3 others identical to the above with different names
#end
and the .m file which should be compiled into the library looks like this:
#import "PPClientData.h"
#implementation PPClientData
#synthesize clientId;
//Synthesize others
-(id)init {
self = [super init];
return self;
}
#end
It is consumed in a single class in the app as follows. If this one function that consumes it is commented out, the linker error goes away (it links to other classes in the library) but with this in, it fails. This is a delegate function for the library.
#import "CPPIntegrationDelegate.h"
#import "PPClientData.h"
#implementation CPPIntegrationDelegate
// Various other functions that work fine
-(PPClientData*)clientData:(PPIntegration*)integration {
PPClientData* dict = [[PPClientData alloc]init]; // This is the line that causes the linker error
dict.clientId = #"whatever";
// set other properties of dict
return dict;
}
I understand what the linker is trying to do and what the error suggests but I don't see what I've missed. Can anyone help?
If you are on Xcode 5.1, try to remove arm64 from Valid Architectures (under Build Settings) and also change the Architectures from "Standard architectures" to just armv7 and armv7s. This might be relevant to you: how to stop xcode5.1 building for 64bit
Well, it wasn't the architectures causing the problem but in some way, xcode or whatever had been confused by the order of the forward declaration of the class I was using and then the definition itself. Initially, the broken code was something like:
BrokenClass.h
// Definitions etc.
GoodClass.h
#class BrokenClass;
- (BrokenClass*)someMethod:(SomeType*) param;
GoodClass.m
#import "BrokenClass.h"
- (BrokenClass*)someMethod:(SomeType*) param
{
}
Which was included into my App by including GoodClass.h into a header file, which forward declared BrokenClass and then included BrokenClass.h into an m file which should have completed the definition, where the class was used.
Anyway, to fix it, I changed the GoodClass code to:
GoodClass.h
#import "BrokenClass.h"
- (BrokenClass*)someMethod:(SomeType*) param;
Removed the #import in the m file and then only included the one GoodClass.h into my app (which brought in the BrokenClass).
Whether this is a bug somehow or more likely, I had too many forward declarations etc. I'm not sure.
I have gone through the ADLivelyTableView demo project but have not been able to import the ADLivelyTableView h and m files into my project successfully. It appears that the main issue is to do with ARC. I have experimented by converting the demo project into arc, specifically but converting just the LDMasterView.m file, and this simply removes all references to releasing objects, and so after this conversion, the use ARC option under build settings is now ON and the app works. So i figured that the ADLivelyTableView .m and .h files dont need converting, but when these are imported into my project, i get all sorts of ARC errors for these two blocks of code:
if (block != _transformBlock) {
Block_release(_transformBlock);
_transformBlock = Block_copy(block);
}
}
and
#implementation ADLivelyTableView
- (void)dealloc {
Block_release(_transformBlock);
[super dealloc];
}
I dont get why these errors didnt show when turning on ARC in the demo project. id prefer finding a solution rather than trying to import my entire application to the demo project instead! The errors are as follows:
ARC Casting Rules: Cast of block pointer type 'ADLivelyTransform (aka NSTimeINterval (^)CALayer*_strong, float) to C pointer type 'const void *' required a bridged cast.
ARC Casting Rules: Cast of C Pointer ....(Same as above)
Also, once this issue is resolved, it is supposed to be as simple as just importing the ADLivelyTableView .h and .m files and then adding the line :
ADLivelyTableView * livelyTableView = (ADLivelyTableView *)self.tableView;
livelyTableView.initialCellTransformBlock = ADLivelyTransformFan;
into my viewDidLoad section? or is that bit supposed to be edited for my specific table?
Thanks for your help,
Regards,
Rami
You can modify the Compiler Flags for ADLivelyTableView.m.
Kindly try to add -fno-objc-arc.
Hi I am looking for a way to perform a database fetch at start up and keep those items in an array.
My solution, although crude was to create an extern variable in viewDidFinishLaunchingWithOptions
I used
appdelegate.h
extern NSArray *listArray;
then
appdelegate.m
NSArray *listArray;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
listArray = [self createGlobalArray];
//other startup code, etc...
The problem is that when I go to any view controller and for example in viewdidload I say
VC1.m
-(void)viewDidLoad{
myVCArray = [NSArray arrayWithArray:listArray];
}
I get two errors: Apple Match-O linker error (directory not found...)
How do i fix this error?
Also is there a better way to do this?
Thank you
Usually linker errors are because things aren't being properly included in your build settings somewhere. I'd make sure that Build Phases > Compile Sources as well as Build Phases > Linked Libraries contain all the files your project needs.