Already checked this question: Weak linking UIPopoverBackgroundView
and already read: http://www.marco.org/2010/11/22/supporting-older-versions-of-ios-while-using-new-apis#fnref:1
I have a custom PopoverBackgroundView declared in a .h and implemented in a .m file. Then, in just one file, I instantiate it like this
self.settingsPopover.popoverBackgroundViewClass = [CustomPopoverBackgroundView class];
I´ve tried doing it like marco says in the link above:
if ([UIPopoverBackgroundView class] != nil) {
self.settingsPopover.popoverBackgroundViewClass = [CustomPopoverBackgroundView class];
}
But I get the same launch error when I run in a 4.3 ipad simulator
dyld: Symbol not found: _OBJC_CLASS_$_UIPopoverBackgroundView
My base sdk is IOS 5.1, and my target deployment is 5.1 as well. Im using LLVM compiler 4.0.
Any ideas? Thanks a lot!
Have you tried using respondsToSelector with the relevant UIPopoverController setBackgroundViewClass method? Remember that properties automatically generate setter and getter methods that you can use in addition to the normal property syntax.
The reason why you're still getting linker errors is because you're still trying to call a method on that class, which doesn't exist.
If it's a case that the entire class doesn't exist, Apple recommends using NSClassFromString(#"UIPopoverController") and checking if the returned result is nil.
Related
ld: warning: Some object files have incompatible Objective-C category definitions. Some category metadata may be lost. All files containing Objective-C categories should be built using the same compiler.
This warning above appeared when I installed the Firebase/Core through cocopods. And I believe it cause an error, because my project can't read the FIRApp.configure() at App deleagate in my project. I am sure I download the GoogleService-Infor.plist and put it in the right place in project, because I done it on my another project before (work properly), my another project didn't have the Objective-C categories warning.
Can anyone help me out?
The process that I've done:
Add pod 'Firebase/Core' in the project podfile, close the xcode.
Open terminal, go to the target project folder, execute pod install.
Appear a warning on terminal (Solution: just put the $(inherited) in the build setting of ALWAYS_..., then problem solve)
[!] The xxxxxx-ebooking [Debug] target overrides the ALWAYS_EMBED_SWIFT_STANDARD_LIBRARIES build setting defined in `Pods/Target Support Files/Pods-xxxxxx-ebooking/Pods-xxxxx-ebooking.debug.xcconfig'. This can lead to problems with the CocoaPods installation:
Use the $(inherited) flag, or
Remove the build settings from the target.
Appear a warning on xcode (This issues are simple, just commit the new files then warning will gone):
file:///Users/yyyyyy/Projects/xxxxxx_projects/xxxxxx-ebooking/Pods/Target%20Support%20Files/Pods-xxxxxx-ebooking/Pods-xxxxxx-ebooking.debug.xcconfig: warning: Missing file: /Users/yyyyyy/Projects/xxxxxx_projects/xxxxxx-ebooking/Pods/Target Support Files/Pods-xxxxxx-ebooking/Pods-xxxxxx-ebooking.debug.xcconfig is missing from working copy
Ignore the issues process of 3, 4, because it are easy to solve. Because the most wired warning is :
ld: warning: Some object files have incompatible Objective-C category definitions. Some category metadata may be lost. All files containing Objective-C categories should be built using the same compiler.
Firebase Analytics has not been created. Please, configure Firebase by calling [FIRApp configure]
I did put the FIRApp.configure() in my project. But when I call FA event on some view did load, it will show this warning. I believe it is because the Objective-C warning.
see if using #nonobjc on your static variable resolve the issue
Finally I solved all bugs, thanks my friend help me to debug and stack overflow community. Here is the solution:
In the beginning I thought this warning "ld: warning: Some object files have incompatible Objective-C category definitions" caused the fail of executing the FIRApp.configure(). But it end out it are two different errors!
First issue, The FIRApp.configure() issues is because my project has error migration when swift 2.2 to 3.0. The xcode suggested me to change the old 2.2 syntax to be private method in AppDelegate:
private func application(application: UIApplication, willFinishLaunchingWithOptions launchOptions: [NSObject : AnyObject]?) -> Bool {
// This method is your app’s first chance to execute code at launch time.
FIRApp.configure()
return true
}
The FIRApp.configure() will never execute because it is not AppDelegate's method. So, changed back to correct syntax will solve the issues:
func application(_ application: UIApplication, willFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
print("Fire! willFinishLaunchingWithOptions")
return true
}
Second issue, if using the below demo syntax and your project has objective-C in third party plug-in or your code, it will cause the warning "Some object files have incompatible Objective-C...". Maybe, because syntax is old for swift 3.0 so it appear this warning.
class var applicationBuildNumber: String {
if let build = Bundle.main.infoDictionary?["CFBundleVersion"] as? String {
return build
}
return "Build Number Not Available"
}
If you using class function, then this warning will disappear:
class func appLocalBuild() -> String {
return Bundle.main.object(forInfoDictionaryKey: kCFBundleVersionKey as String) as! String
}
I'm working on a plugin for Xcode. It is supposed to be written in Swift.
When I start with a fresh plugin project (I'm using this Xcode Plugin template which is also available via Alcatraz) the project compiles and runs fine.
The pluginDidLoad method is getting called right after Xcode starts. As soon as I add any Objective-C file (and a bridging header of course) the pluginDidLoad method is not getting called anymore.
The Objective-C file might be as simple as an empty class that is a subclass of NSObject.
Removing the target-memberbership (for the plugin-target) from the newly created Objective-C (.m) file the aforementioned mentioned method is getting called again.
Has anyone developed a Xcode plugin in Swift that also uses Objective-C files before and got this working?
Update
It seems that my original solution only works with Swift only projects because Xcode always takes the objective c class if you have one.
So here is another trick: Extend the NSObject class by the function class func pluginDidLoad(bundle: NSBundle) {} and initialize your plugin there. Then it doesn't matter on which class it is called. You might have to check that also all Swift classes subclass NSObject. I pushed it to my repository that you can have a look
Original Post
I think I could reproduce the problem now. To simplify the problem, let's say that we have only two swift classes PluginMain and PluginHelper.
As you said, sometimes the plugin isn't getting called for some mysterious reason. I was struggling with the problem again and I was wondering how Xcode knows which class is the main class. So I came up with the idea to put the following initializer in both classes PluginMain and PluginHelper
class func pluginDidLoad(bundle: NSBundle) {
let appName = NSBundle.mainBundle().infoDictionary?["CFBundleName"] as? NSString
if appName == "Xcode" {
//sharedPlugin = SwiftySafe(bundle: bundle)
//initialize your shared plugin
}
}
By putting a breakpoint or log message in pluginDidLoad in both classes, I notices that Xcode isn't ignoring the plugin, it is just loading the wrong class (e.g. PluginHelper instead of PluginMain).
The Solution
It turns out that Xcode uses the class that is compiled first as the main class and calls pluginDidLoad only on that. So you can change that by reordering the "Compiled Sources" under your target settings->Build Phases. Move your main class so that it is on top. In the following image you find an example from my project. SwiftySafe is my main class.
My example
You will find my project here https://github.com/creinders/SwiftySafe if you want to compare the settings.
The pluginDidLoad method is called on the principal class. When the principal class is a Swift class, you have to include the module name in the NSPrincipalClass Info.plist key.
So if your target name is MyPlugin and your principal class is MyClass, set NSPrincipalClass to MyPlugin.MyClass.
Also make sure that MyClass inherits from NSObject.
Sometimes you need to tell Xcode to reload bundle. Run this and restart Xcode
defaults delete com.apple.dt.Xcode DVTPlugInManagerNonApplePlugIns-Xcode-7.3
When I create a new project with Xcode 4.4 and add these lines:
NSDictionary *test = #{ #"key" : #"test value" };
NSString *value = test[#"key"];
NSLog(#"value is: %#", value);
it compiles with no warnings and executes as expected.
Adding the same lines to an existing project produces the compiler error:
NSString *value = test[#"key"]; <-- Expected method to read dictionary element not found on object of type 'NSDictionary *'
I compared both projects' target build settings but nothing leapt out at me.
Update:
The new project that successfully compiled was for OSX. I tried another new one for iOS with the above lines and it fails to compile, same as my pre-existing (iOS) project.
This has nothing to do with old vs. new project, but rather is a factor of the SDK you use. The problem you're running into is that while this is a compiler feature, it requires SDK support. The iOS 5 SDK does not provide that support, though the iOS 6 SDK does.
For that reason, now you should just use the iOS 6 SDK. Read on if you want to use object subscripting with the iOS 5 SDK.
All you need to do is add a header file so that the compiler will try the call. There's no need to add an implementation; it's handled automatically by arclite. (If you are not using ARC, you will have to force the linker to include arclite. But you still don't have to actually switch to it.)
Create a new interface file, NSObject+subscripts.h.
#if __IPHONE_OS_VERSION_MAX_ALLOWED < 60000
#interface NSDictionary(subscripts)
- (id)objectForKeyedSubscript:(id)key;
#end
#interface NSMutableDictionary(subscripts)
- (void)setObject:(id)obj forKeyedSubscript:(id <NSCopying>)key;
#end
#interface NSArray(subscripts)
- (id)objectAtIndexedSubscript:(NSUInteger)idx;
#end
#interface NSMutableArray(subscripts)
- (void)setObject:(id)obj atIndexedSubscript:(NSUInteger)idx;
#end
#endif
I've put this chunk on github.
Note: I used to suggest adding the required methods to NSObject before explaining how to add them only to the relevant objects. In retrospect, I believe this was an error on my part; it led to errors being caught at runtime rather than compile time, unlike the approach now presented here. That approach is still on my blog, but I now believe it to be more of a cool hack than a useful approach.
Source:
Peter Steinberger, Using Subscripting With Xcode 4.4 and iOS 4.3+
I'm attempting to use this approach, described by Marco Arment, for checking if a class exists before using it. With the correct settings, classes are automatically weak-linked when it's appropriate. As Marco describes, "you can safely subclass or have pointers to whatever you want (as long as you’re careful not to instantiate them when they’re not available)".
My app runs fine on iOS 5. I've followed the conditions mentioned at the link:
Base SDK is Latest iOS (iOS 5.1)
Deployment Target is iOS 4.0
Compiler for C/C++/Objective-C is Apple LLVM compiler 3.1 (also tried LLVM GCC 4.2)
Any time I reference NSMetadataQuery I'm making sure the class exists first:
if ([NSMetadataQuery class] != nil) …
Despite all this my app crashes immediately on launch if I try to run it on an iPod touch with iOS 4.2.1:
dyld: Symbol not found: _OBJC_CLASS_$_NSMetadataQuery
I've tried commenting out all the code any my app runs fine. As soon as I add back in a single reference to NSMetadataQuery, it crashes. I've even tried this:
if ([NSMetadataQuery class] != nil) NSLog(#"OK");
Simply including that line, and no other reference to NSMetadataQuery, crashes the app. Even more strange, checking for other iOS 5 classes doesn't cause any problems:
if ([UIDictationPhrase class] != nil) NSLog(#"OK");
That works fine, as expected.
I have been able to work around the problem using the uglier NSClassFromString() to make sure the class exists, but I'd love to know why the other approach isn't working.
I don't have an explanation to this but I ran into the same problem as you. No matter what I/you do, NSMetadataQuery just won't be weak linked...
Refer to this answer, which is really the best one in another question:
https://stackoverflow.com/a/8426591/129202
In short, other auto weak linking seems to work, it's just NSMetadataQuery* that you have to remove from source and replace with id. Instantiate the class with NSClassFromString() etc. No hiccups on other classes like UIDocument however so you can safely use those in the normal sweat free way.
NSMetadataQuery is available in iOS 5.0 and above, so any versions below that has no clue as to what it is. By merely using it in your code, the class name will be added to a symbol table and looked-up when the app launches.
I am running cocos2d 1.0.1. I am getting Warning Errors regarding this code saying that the initWithFrame method is not found. I believe it is responsible for crashing my application, while logging "Unknown Error"
glView = [[EAGLView alloc] initWithFrame:[window bounds]
pixelFormat:kEAGLColorFormatRGBA8
depthFormat:GL_DEPTH_COMPONENT24_OES
preserveBackbuffer:NO];
This is the Build WARNING I got:
WARNING: No '-initWithFrame: pixelFormat:
depthFormat:preserveBackbuffer:' method found
Reading forum posts from a year ago, Riq recommended the above method posted, but that did not work.
I do have my EAGLView.h/m files, they are under the iOS subFolder of the Platforms subFolder.
I tried adding an #class EAGLView; declaration in the App.h file, but I still couldn't even get Xcode to jump to the definition of the EAGLView class. Moving the two EAGLView .h and .m files up to the main Cocos2d folder did nothing either.
My question is: how do I get these files to talk, because there's clearly a lack of communication.
The format of EAGLView initWith… methods have changed. In your case you simply need to add the remaining additional parameters as described in the link.