Re: How to avoid warning?
On Jan 22, 2013, at 8:12 PM, Jens Alfke j...@mooseyard.com wrote: @interface SomeFictionalClassName - (id) initWithManager: (Foo*)manager; @end That feels a bit dirty to me. I'd recommend using a protocol instead. As long as the compiler has seen the method *somewhere*, it will consider it having been declared. So @protocol AvoidCompilerWarning - (id) initWithManager: (Foo*)manager; @end is, for the purposes of this particular discussion, equivalent to Jens's fictional class interface, but doesn't imply that such a class might exist to a (human) reader. Cheers, -- Uli Kusterer The Witnesses of TeachText are everywhere... http://www.zathras.de ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 8:28 PM, Andy Lee ag...@mac.com wrote: To be extra fail-safe, you might want to perform a cast to be sure the right initWithManager: gets called: if ([myClass conformsToProtocol:@protocol(MyProtocol)]) myObj = [(id MyProtocol)[myClass alloc] initWithManager:self]; else myObj = [[myClass alloc] init]; This only works for classes that actually declare themselves to be in conformance with this protocol, though. Even if a class implements all the methods in a protocol, conformsToProtocol: will return NO if it doesn't have the protocol name on the @interface (or on the @implementation line). IMO the nicest way to do this (if you can't make all your classes conform to the protocol by declaring them as @interface Foo : NSObject UKCanInitWithManagerProtocol, which would definitely be the cleanest approach), would be: @protocol UKCanInitWithManagerProtocol -(id) initWithManager: (Foo*)inManager; @end ... if( [myClass respondsToSelector: @selector(initWithManager:)] ) myObj = [(idUKCanInitWithManagerProtocol)[myClass alloc] initWithManager: self]; else myObj = [[myClass alloc] init]; Though I would recommend choosing a different name. E.g. -initWithBarManager: if the manager class is called UKBarManager. Manager alone is too generic a word, and someone might have declared it in ObjC++ and taking a C++ object and then you're screwed. Cheers, -- Uli Kusterer The Witnesses of TeachText are everywhere... http://www.zathras.de ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 23, 2013, at 8:22 AM, Uli Kusterer witness.of.teacht...@gmx.net wrote: @protocol UKCanInitWithManagerProtocol -(id) initWithManager: (Foo*)inManager; @end ... if( [myClass respondsToSelector: @selector(initWithManager:)] ) myObj = [(idUKCanInitWithManagerProtocol)[myClass alloc] initWithManager: self]; else myObj = [[myClass alloc] init]; Well, the extra-super-defensive approach would be to not only check respondsToSelector:, but to check that the method signature of the object's implementation matches what's declared in the protocol. :) But yeah, you can't rely on conformsToProtocol: if you don't have the luxury of making the relevant classes conform to the protocol. --Andy ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
That's wont help because myClass is a variable created from a String. as in: -void methodXXX:(NSString*) theClassName myClass = NSClassFromString(theClassName); if (myClass == nil) return; myObj = [[myClass alloc] initWithManager:self]]; } To whoever said write better code that has types defined, this code is fine. You can't know the Class here which is why I'm checking to see if the Class supports the selector first. I could use performSelector but not sure how that would work with the alloc method: myObj = [[myClass alloc] performSelector(@selector (initWithManager:) withObject:self]; Would this work? Cheers Dave On 21 Jan 2013, at 18:42, Quincey Morris wrote: On Jan 21, 2013, at 10:14 , Dave d...@looktowindward.com wrote: myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? You need to #import a header file with an @interface declaration for the 'initWithManager:' method. The rule is that when the compiler sees a message send to a receiver of type 'id' (which is the return type of 'alloc'), it needs to have seen *some* declaration of that method. If it has seen more than one declaration, BTW, the declarations must all be compatible in terms of parameter and return types. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 21 Jan 2013, at 18:44, Steve Sisak wrote: At 6:14 PM + 1/21/13, Dave wrote: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? You could try declaring initWithManager: in a category on the class visible only to your implementation code. (i.e. at the top of your .m file) The class name is passed in as a string and the class is formed from that, so I can't pre-declare it. Please see my other reply. Cheers Dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 21 Jan 2013, at 22:12, Jens Alfke wrote: On Jan 21, 2013, at 10:14 AM, Dave d...@looktowindward.com wrote: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) Off-topic: instead of using the Obj-C runtime’s C API, you can express this as if ([myClass instancesRespondToSelector: @selector (initWithManager:)] == NO) —Jens Ok, cool, thanks for that, I still have the same problem though when I call the initWithManager. Cheers Dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
myObj = [[myClass alloc] performSelector(@selector(initWithManager:) withObject:self]; Would this work? You could do : id myObj =[myClass alloc]; myObj = [myObj performSelector(@selector(initWithManager:) withObject:myObj]; ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 22 janv. 2013, at 18:34, Jean Suisse jean.li...@gmail.com wrote: myObj = [[myClass alloc] performSelector(@selector(initWithManager:) withObject:self]; Would this work? You could do : id myObj =[myClass alloc]; myObj = [myObj performSelector(@selector(initWithManager:) withObject:myObj]; [Sorry, I did hit send by mistake] This (above) implies that the manager is self. Not that myObj is used as self when calling init. Or you could declare a protocol myProtocol that defines initWithManager: and have the following declaration for myObj: id myProtocol myObj = … This would avoid the use of @selector. You could also test if myObj responds to the selector selector just after calling alloc. Jean ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 10:23 AM, Dave wrote: On 21 Jan 2013, at 18:44, Steve Sisak wrote: At 6:14 PM + 1/21/13, Dave wrote: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? You could try declaring initWithManager: in a category on the class visible only to your implementation code. (i.e. at the top of your .m file) The class name is passed in as a string and the class is formed from that, so I can't pre-declare it. Please see my other reply. If in fact myClass may be any number of classes that may implement certain methods, the right way to do this is using a protocol. Protocols are designed to fit this purpose. I don't recall, however, the exact method to hint to the compiler enough to avoid the warning. Importing the protocol header may be sufficient. HTH, Keary Suska Esoteritech, Inc. Demystifying technology for your home or business ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 22 Jan 2013, at 17:34, Jean Suisse wrote: myObj = [[myClass alloc] performSelector(@selector (initWithManager:) withObject:self]; Would this work? You could do : id myObj =[myClass alloc]; myObj = [myObj performSelector(@selector(initWithManager:) withObject:myObj]; Thanks for this, I was wondering if that would work too. I want to pass self (the instance of the current class) to initWithManager though. So can I just use: myObj = [myObj performSelector(@selector(initWithManager:) withObject:self]; Thanks Dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 22 Jan 2013, at 18:07, Keary Suska wrote: On Jan 22, 2013, at 10:23 AM, Dave wrote: On 21 Jan 2013, at 18:44, Steve Sisak wrote: At 6:14 PM + 1/21/13, Dave wrote: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? You could try declaring initWithManager: in a category on the class visible only to your implementation code. (i.e. at the top of your .m file) The class name is passed in as a string and the class is formed from that, so I can't pre-declare it. Please see my other reply. If in fact myClass may be any number of classes that may implement certain methods, the right way to do this is using a protocol. Protocols are designed to fit this purpose. I don't recall, however, the exact method to hint to the compiler enough to avoid the warning. Importing the protocol header may be sufficient. This has to work with classes that exist already as well as classes that don't. If initWithManager is defined in the class in question knows what it is being called like this, if not then it defaults to the regular NSObject init. For instance it could be NSString or NSArray that is the class, in which case it won't have initWithManager so it calls init instead. All the Best Dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 9:24 AM, Dave d...@looktowindward.com wrote: Ok, cool, thanks for that, I still have the same problem though when I call the initWithManager. Others answered this already. To recap: The compiler needs to see a declaration of an -initWithManager: method before it parses this line. So you have to either #import the header that declares that method, or if there’s no such header, put a category interface at the top of this .m file that defines the method. —Jens ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 22 Jan 2013, at 18:26, Jens Alfke wrote: On Jan 22, 2013, at 9:24 AM, Dave d...@looktowindward.com wrote: Ok, cool, thanks for that, I still have the same problem though when I call the initWithManager. Others answered this already. To recap: The compiler needs to see a declaration of an -initWithManager: method before it parses this line. So you have to either #import the header that declares that method, or if there’s no such header, put a category interface at the top of this .m file that defines the method. That won't work either, you have to use performSelector:withObject: which seems to do the trick nicely! Cheers Dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 9:23 AM, Dave d...@looktowindward.com wrote: That's wont help because myClass is a variable created from a String. But it will help, because Quincey's suggestion is not contingent on the type of the object that you send the message to. The compiler is merely asking that you have declared a method with that selector *somewhere* in this translation unit so that it knows (or at least has a really good guess) about the formal signature of the method you're calling. This is because (1) we would like to do at least some minimal type-checking on the method call, like whether 'self' can be passed as that argument, and (2) calling conventions can differ depending on the formal signature of the method, and we need to get that right for the call to succeed. You could argue that in the specific case of an init method, we should guess about what this signature is; but (1) there really are exceptions to the conventions, even with init methods, and (2) there's really no good reason for you to not have at least one declaration somewhere in the translation unit. John. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 1:26 PM, Jens Alfke j...@mooseyard.com wrote: On Jan 22, 2013, at 9:24 AM, Dave d...@looktowindward.com wrote: Ok, cool, thanks for that, I still have the same problem though when I call the initWithManager. Others answered this already. To recap: The compiler needs to see a declaration of an -initWithManager: method before it parses this line. So you have to either #import the header that declares that method, or if there’s no such header, put a category interface at the top of this .m file that defines the method. To spell it out even more... when the compiler sees this: myObj = [[myClass alloc] initWithManager:self]; ...it knows that [myClass alloc] returns an id. Since it doesn't have any hint as to the class of that id, the compiler will be permissive/optimistic/trusting and allow any message to be sent to it without warning -- *IF* it has seen a declaration of that message somewhere, anywhere, for any class. So you need to force the compiler to see such a declaration. Even importing a totally unrelated class will do. As has been suggested, you could import a class that declares initWithManager:. Or you could add your own declaration of something else -- it could be a category, a protocol, *anything* -- that declares the method. // This works (category). @interface NSObject (AvoidCompilerWarning) - (id)initWithArg:(id)arg; @end // Or this also works (protocol). @protocol AvoidCompilerWarning - (id)initWithArg:(id)arg; @end --Andy ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 9:23 AM, Dave d...@looktowindward.com wrote: You could try declaring initWithManager: in a category on the class visible only to your implementation code. (i.e. at the top of your .m file) The class name is passed in as a string and the class is formed from that, so I can't pre-declare it. Please see my other reply. Sure you can: @interface SomeFictionalClassName - (id) initWithManager: (Foo*)manager; @end Put that at the top of your source file and the warning will go away, because the compiler is now confident that there exists an -initWithManager: method. (The fact that you’ve declared it on a completely fictional class doesn’t matter.) As others have said, though, it really sounds like what you want is a protocol that defines the -initWithManager: method. This is a better solution because it adds more type-safety — if you ever rename -initWithManager:, but don’t fix all the places it’s used, the compiler will then be able to complain about the places you missed, so you’ll avoid confusing runtime errors. —Jens ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 12:58 PM, Andy Lee ag...@mac.com wrote: // Or this also works (protocol). @protocol AvoidCompilerWarning - (id)initWithArg:(id)arg; @end Really, a protocol is what you ought to be doing. Make a protocol with -initWithManager: in it, and then make all the classes that might get passed to this method comply with your protocol. Then, do this: if ([myClass conformsToProtocol:@protocol(MyProtocol)]) myObj = [[myClass alloc] initWithManager:sel]]; else myObj = [[myClass alloc] init]; The advantage to this method is a simple one: Suppose some random class happens to implement a method named -initWithManager:, but that method has nothing to do with your -initWithManager: other than a coincidental title, and takes a completely different type of object. Your original code will result in unpredictable behavior in this case (and probably throw an exception leading to a crash). If you use a protocol, you'll know not just that the method responds to something named -initWithManager:, but that it's *your* -initWithManager: Charles ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 2:19 PM, Charles Srstka cocoa...@charlessoft.com wrote: On Jan 22, 2013, at 12:58 PM, Andy Lee ag...@mac.com wrote: // Or this also works (protocol). @protocol AvoidCompilerWarning - (id)initWithArg:(id)arg; @end Really, a protocol is what you ought to be doing. Make a protocol with -initWithManager: in it, and then make all the classes that might get passed to this method comply with your protocol. Then, do this: if ([myClass conformsToProtocol:@protocol(MyProtocol)]) myObj = [[myClass alloc] initWithManager:sel]]; else myObj = [[myClass alloc] init]; The advantage to this method is a simple one: Suppose some random class happens to implement a method named -initWithManager:, but that method has nothing to do with your -initWithManager: other than a coincidental title, and takes a completely different type of object. Your original code will result in unpredictable behavior in this case (and probably throw an exception leading to a crash). If you use a protocol, you'll know not just that the method responds to something named -initWithManager:, but that it's *your* -initWithManager: Makes sense, especially since it sounds like you have enough control of the class to declare it as conforming to the protocol. To be extra fail-safe, you might want to perform a cast to be sure the right initWithManager: gets called: if ([myClass conformsToProtocol:@protocol(MyProtocol)]) myObj = [(id MyProtocol)[myClass alloc] initWithManager:self]; else myObj = [[myClass alloc] init]; --Andy ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 1:28 PM, Andy Lee ag...@mac.com wrote: On Jan 22, 2013, at 2:19 PM, Charles Srstka cocoa...@charlessoft.com wrote: On Jan 22, 2013, at 12:58 PM, Andy Lee ag...@mac.com wrote: // Or this also works (protocol). @protocol AvoidCompilerWarning - (id)initWithArg:(id)arg; @end Really, a protocol is what you ought to be doing. Make a protocol with -initWithManager: in it, and then make all the classes that might get passed to this method comply with your protocol. Then, do this: if ([myClass conformsToProtocol:@protocol(MyProtocol)]) myObj = [[myClass alloc] initWithManager:sel]]; else myObj = [[myClass alloc] init]; The advantage to this method is a simple one: Suppose some random class happens to implement a method named -initWithManager:, but that method has nothing to do with your -initWithManager: other than a coincidental title, and takes a completely different type of object. Your original code will result in unpredictable behavior in this case (and probably throw an exception leading to a crash). If you use a protocol, you'll know not just that the method responds to something named -initWithManager:, but that it's *your* -initWithManager: Makes sense, especially since it sounds like you have enough control of the class to declare it as conforming to the protocol. To be extra fail-safe, you might want to perform a cast to be sure the right initWithManager: gets called: if ([myClass conformsToProtocol:@protocol(MyProtocol)]) myObj = [(id MyProtocol)[myClass alloc] initWithManager:self]; else myObj = [[myClass alloc] init]; --Andy That's a good fix. In addition to being more fail-safe, that also lets clang and Xcode know exactly what you intend here, so that if you decide someday to do something like rename the initWithManager: method using Xcode's Refactor feature, it should get this invocation of the method as well. Charles ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 22, 2013, at 10:15 AM, Dave d...@looktowindward.com wrote: This has to work with classes that exist already as well as classes that don't. If initWithManager is defined in the class in question knows what it is being called like this, if not then it defaults to the regular NSObject init. For instance it could be NSString or NSArray that is the class, in which case it won't have initWithManager so it calls init instead. That will still work fine with protocols. NSString doesn’t implement your protocol, so your code skips the custom init and just calls -init instead. If you don’t believe us, then try typing in and compiling the examples people have given, and experiment with them until you’re convinced. But this thread is kind of going around in circles, with you asking us for advice and then not accepting it. —Jens ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 22 Jan 2013, at 21:27, Jens Alfke wrote: On Jan 22, 2013, at 10:15 AM, Dave d...@looktowindward.com wrote: This has to work with classes that exist already as well as classes that don't. If initWithManager is defined in the class in question knows what it is being called like this, if not then it defaults to the regular NSObject init. For instance it could be NSString or NSArray that is the class, in which case it won't have initWithManager so it calls init instead. That will still work fine with protocols. NSString doesn’t implement your protocol, so your code skips the custom init and just calls -init instead. If you don’t believe us, then try typing in and compiling the examples people have given, and experiment with them until you’re convinced. But this thread is kind of going around in circles, with you asking us for advice and then not accepting it. I just wanted rid of the warning which I have, so I'm happy. I tried with the protocols etc. but it makes the method very messy and I have to double up on local variables etc. The fact is that it's a one parameter method that accepts an id and returns an id. If someone did define initWithManager on a class then it's likely to match the method pattern anyway, so it probably wouldn't help stop problems like that occurring anyway, and I'm not defining the classes that have the initWithManager method in them, so I can't define the class as conforming to a protocol. Bottom line, it works as it is and it isn't that fragile, so it ain't broke and ain't likely to break then leave it alone is my motto. Thanks a lot for all your help All the Best Dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
How to avoid warning?
Hi All, I have the following code: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? Thanks in Advance Dave ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 21, 2013, at 10:14 AM, Dave d...@looktowindward.com wrote: Hi All, I have the following code: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? What warning do you get? (Its not obvious from context). -- David Duncan ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On 21 Jan 2013, at 18:14, Dave d...@looktowindward.com wrote: Hi All, I have the following code: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? Simple, Write better code where you know the types you're dealing with ;). Bob ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
myObj = [[myClass alloc] initWithManager:sel]]; Is sel meant to be self? On Jan 21, 2013, at 1:14 PM, Dave d...@looktowindward.com wrote: Hi All, I have the following code: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 21, 2013, at 10:14 , Dave d...@looktowindward.com wrote: myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? You need to #import a header file with an @interface declaration for the 'initWithManager:' method. The rule is that when the compiler sees a message send to a receiver of type 'id' (which is the return type of 'alloc'), it needs to have seen *some* declaration of that method. If it has seen more than one declaration, BTW, the declarations must all be compatible in terms of parameter and return types. ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
At 6:14 PM + 1/21/13, Dave wrote: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) myObj = [[myClass alloc] init]; else myObj = [[myClass alloc] initWithManager:sel]]; I get a warning on the initWithManager: statement (Obviously), how to avoid the warning or otherwise fix it? You could try declaring initWithManager: in a category on the class visible only to your implementation code. (i.e. at the top of your .m file) HTH, -Steve ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
Re: How to avoid warning?
On Jan 21, 2013, at 10:14 AM, Dave d...@looktowindward.com wrote: if (class_RespondsToSelector(myClass,@selector(initWithManager:) == NO) Off-topic: instead of using the Obj-C runtime’s C API, you can express this as if ([myClass instancesRespondToSelector: @selector(initWithManager:)] == NO) —Jens ___ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
