I know this is a common subject but I did not find any answer to help me out with this problem.
Well, I do have (by now) 3 .h files,
One is the superclass of the two others.
Superclass : ExportationAutoFilterNew
#import <Foundation/Foundation.h>
#import <HIDDEN/PluginFilter.h>
#class MyOutlineView;
#interface ExportationAutoFilterNew : PluginFilter
#property (assign, nonatomic) NSUserDefaults *prefs;
#property (assign, nonatomic) MyOutlineView *databaseOutline;
#end
Then, sub-classes : DetectNewExams & ExportExams
#import <Foundation/Foundation.h>
#import <HIDDEN/PluginFilter.h>
#import "ExportationAutoFilterNew.h"
#interface DetectNewExams : ExportationAutoFilterNew
- (void)detectExams:(NSDate*)currentDate timeInterval:(double)timeInterval afterExitHidden:(BOOL)check;
And
#import <Foundation/Foundation.h>
#import <HIDDEN/PluginFilter.h>
#import "ExportationAutoFilterNew.h"
#interface ExportExams : ExportationAutoFilterNew
- (void)exportExams:(NSManagedObject*)curObj;
The .m goes like this
Superclass : ExportationAutoFilter
#import <HIDDEN/PreferencesWindowController.h>
#import <HIDDEN/browserController.h>
#import "ExportationAutoFilterNew.h"
#import "DetectNewExams.h"
#implementation ExportationAutoFilterNew
Xcode for this file (ExportationAutoFilterNew.m) :
Instance method '-detectExams:timeInterval:afterExitHidden:' not found (return type defaults to 'id')
For the call of :
[self detectExams:lastExportDate timeInterval:0 afterExitHidden:YES];
Sub-classes : DetectNewExams
#import <HIDDEN/PreferencesWindowController.h>
#import <HIDDEN/browserController.h>
#import "DetectNewExams.h"
#import "ExportExams.h"
#implementation DetectNewExams
In this file (DetectNewExams.m), Xcode says :
Instance method '-exportExams:' not found(return type defaults to 'id')
Calling :
[self exportExams:curObj];
And then : ExportExams
#import <HIDDEN/PreferencesWindowController.h>
#import <HIDDEN/browserController.h>
#import "ExportExams.h"
#implementation ExportExams
I'm wasting hours on this thing and I can't figure the problem out, may you help me ? I looked up for compiling circle but I don't think I created one with my imports ..
Thanks.
Your interface is not properly declared. Try this.
#interface ExportationAutoFilterNew : PluginFilter
#property (nonatomic) NSUserDefaults *prefs;
#property (nonatomic) MyOutlineView *databaseOutline;
#end
Now that you have posted the actual error, this becomes more clear. But you still haven't posted enough context.
Instance method '-detectExams:timeInterval:afterExitHidden:' not found (return type defaults to 'id')
That means that the method declaration hasn't been seen at the time the code was compiled or the method is declared on some class that whatever was being called is not an instance of.
Since you haven't shown the call site or the declaration of the variable being called, this is a guess. The method is declared on the DetectNewExams class. I'd bet you have a variable that points to an instance of ExportationAutoFilterNew and, therefore, the compiler is correctly warning that the method doesn't exist on the class.
Related
In my MyClass.h, I have this:
#import "AClass.h"
#interface MyInterface : UIViewController <UIScrollViewDelegate>
#property (strong, nonatomic) AClass *ptr;
#end
But when I compile it, I get an error saying Unknown type name 'AClass' , did you mean 'BClass'.
What I don't understand it I already have "#import "AClass.h", how can I fix my error?
In AClass.h, I have
#interface AClass : UICollectionViewFlowLayout
#end
And both AClass.h and MyClass.h are in the same directory.
Thank you.
(This answer is obsolete since the question was changed including the displayed code)
It's your headerfile, right? So don't import yourself.
In MyClass.m you need #import "MyClass.h", but not in the header file of MyClass itself.
I'm having a problem when I try to add a second protocol. The first one is working just fine. So I created a test application to try out using two protocols (because I'm still learning how to use protocols). I do not know why I am having so much trouble understanding protocols. I've even gone through tutorials and still struggle with them.
My first issue when I tried to add the second protocol and use it I received the following error:
Assigning to ‘id’ from incompatible type ‘ *const _strong'
But, let's ignore that for now, because my test application is giving me this error for both protocols in my test app:
Cannot find protocol declaration
So, I will post the code for my test application, because I MUST understand the basics before tackling more difficult issues.
DelegateA Header
#import <Foundation/Foundation.h>
#protocol IDDelegateADelegate <NSObject>
#end
#interface IDDelegateA : NSObject
//other properties here
#property (nonatomic, assign) id<IDDelegateADelegate> delegateA;
#end
DelegateA Implementation
#import "IDDelegateA.h"
#implementation IDDelegateA
#synthesize delegateA;
//other methods and properties go here
#end
DelegateB Header
#import <Foundation/Foundation.h>
#protocol IDDelegeteBDelegate <NSObject>
#end
#interface IDDelegeteB : NSObject
//other properties here
#property (nonatomic, assign) id<IDDelegeteBDelegate> delegateB;
#end
DelegateB Implementation
#import "IDDelegeteB.h"
#implementation IDDelegeteB
#synthesize delegateB;
//other methods and properties go here
#end
The test class Header that uses these delegates
#import <Foundation/Foundation.h>
#import "IDDelegateA.h"
#import "IDDelegeteB.h"
#interface IDTestingDelegates : NSObject <IDDelegateA, IDDelegateB>
#end
Right here I receive the Cannot find protocol declaration error for both delegates. I've been searching on SO as well as going through tutorials and sample code. Best answer on SO was here. But I'm just not getting what I'm doing wrong. Can somebody please point out what I am missing here?
#interface IDTestingDelegates : NSObject <IDDelegateA, IDDelegateB>
should be
#interface IDTestingDelegates : NSObject <IDDelegateADelegate, IDDelegeteBDelegate>
You have to list the protocols in <...>, not interfaces.
#interface declares a class, while the ClassName <X> syntax expects X to be a protocol (in your declaration of IDTestingDelegates).
Not sure exactly what you were trying to achieve here.
I know this question has been asked a lot, but it doesn't help me...
I have made a lot of delegate protocol in my projects, but this happened a lot...
I got an error cannot find protocol declaration for ''. The weird thing is that when i do this for the first time :
id<dataForEventDelegate> dataEventDelegate;
It works, i build, i try a rebuild and PAF doesn't find the protocole anymore...
my code looks like that in my delegate .H :
#protocol dataForEventDelegate <NSObject>
-(void)setStartDateLabel:(NSDate *)startDaleLabel;
-(void)setEndDateLabel:(NSDate *)endDaleLabel;
-(void)setDefaultCalendarLabel;
#end
#interface EventViewController : UIViewController <UITextFieldDelegate, UIPickerViewDelegate, dataForEventDelegate>
this is in my file.h which should use the delegate
#import "EventViewController.h"
#interface datePickerController : UIPickerView <UIPickerViewDelegate, UIPickerViewDataSource>
{
id<dataForEventDelegate> dataEventDelegate;
NSMutableArray *dateArray;
}
#property(nonatomic, strong) id<dataForEventDelegate> dataEventDelegate;
this dataForEventDelegate is not found !! BUT IT SHOULD :(
It seems you have not made datePickerController conform to the protocol, should be:
#interface datePickerController : NSObject <UIPickerViewDelegate, UIPickerViewDataSource, dataForEventDelegate>
I would also question why you are declaring datePickerController as a UIPickerView. See My example is NSObject.
I am also not sure why you would want EventViewController to conform to its own protocol. See it removed here:
#interface EventViewController : UIViewController <UITextFieldDelegate, UIPickerViewDelegate>
Since I had a import-cycle recently, I'm moving all #import statements (concerning my own files) from the header into the corresponding .m-file. I also added #class and #protocol forward-declarations to soothe the compiler. However, I still get he following warning:
Cannot find the protocol definition for 'MyCustomDelegate'.
As I said, there is an #protocol MyCustomDelegate before I use it in the #interface-Block. Interestingly this warning only occurs if the corresponding delegate is declared in another file (whose header is imported in the .m-file).
I read that one solution is to declare the delegate in a separate header file and import that file directly in the header of the class that implements the delegate. Is this really the way to go? Are there any other solutions? I think those delegates already bloated our code enough, now I should go on and even declare an own file for it?
Small sample code to better illustrate the problem:
NewFooController.h
#import <UIKit/UIKit.h>
#protocol NewFooControllerDelegate;
#interface NewFooController : UITableViewController
#property (nonatomic, weak) id<NewFooControllerDelegate> delegate;
#end
#protocol NewFooControllerDelegate
#end
HomeTableViewController.h
#import <UIKit/UIKit.h>
#protocol NewFooControllerDelegate;
// warning points to line below
#interface HomeTableViewController : UITableViewController <NewFooControllerDelegate>
#end
HomeTableViewController.m
#import "HomeTableViewController.h"
#import "NewFooController.h"
#implementation HomeTableViewController
#end
HomeTableViewController.h references the protocol, but it hasn't been declared yet.
If you import NewTaskController.h in HomeTableViewController.h before it attempts to use it, it should solve your problem.
Of course you can then remove the import from HomeTableViewController.m
Not sure if this is "best way", but try import header of class that implement protocol before class header file.
HomeTableViewController.m
#import "NewFooController.h"
#import "HomeTableViewController.h"
#implementation HomeTableViewController
#end
And you can remove protocol declaration in HomeTableViewController.h
#import <UIKit/UIKit.h>
#interface HomeTableViewController : UITableViewController <NewFooControllerDelegate>
#end
Sorry, couldn't find a more appropriate title.
In My code I have two classes which should know of each others existence. So I use an instance variable which points to the other class. For that to work (I guess?) the other classes headers file should be imported so it knows which methods it has and such.
Here is my code (stripped down)
MainMenuController.h:
#import <Cocoa/Cocoa.h>
#import "IRCConnection.h"
#interface MainMenuController : NSViewController {
IRCConnection *ircConnection;
}
#property (strong) IRCConnection *ircConnection;
#end
IRCConnection.h:
#import <Foundation/Foundation.h>
#import "MainMenuController.h"
#interface IRCConnection : NSObject {
MainMenuController *mainMenuController;
}
#property (strong) MainMenuController *mainMenuController;
#end
As you can see they both import each other, but this creates an error (Unknown type name 'IRCConnection') in one, and in the other Unknown type name 'MainMenuController'.
However when the connection is just one way (e.g. only MainMenuController knows about IRCConnection) and thus there is only an import statement in one of the two, it works fine.
How can I have them to know about each other? In both ways.
Hope this question makes any sense.
you could remove the import from IRCConnection.h and use a #class statement instead.
like this:
#import <Foundation/Foundation.h>
#class MainMenuController;
#interface IRCConnection : NSObject {
then add a #import "MainMenuController.h" to IRCConnection.m
In the header, use forward declaration:
#class IRCConnection;
#interface MainMenuController : NSViewController {
IRCConnection *ircConnection; // ok
}
In the source file (.m), do #import.
You cannot have circular imports. You need to break them up, or introduce some forward declarations.