I've got a property that I want to change the name of. Basically I want the old property to return/set the value of the new property so existing code doesn't break, but it'll throw warnings to use the new name.
This is in my header file:
#property (nonatomic, strong) MyClass *newProperty;
#property (nonatomic, strong) MyClass *oldProperty __attribute__((deprecated));
To make oldProperty's getters and setters just set/return newProperty's values in the implementation i'd like to do something like
#synthesize oldProperty=_newProperty;
This throws an error 'oldProperty and newProperty both claim instance variable _newProperty'. Whats the best way to achieve what I want to do? (I'm deprecating and renaming about 30 properties)
Setting the getters/setters manually returns the same error
- (void)setOldProperty:(MyClass *)oldProperty {
_newProperty=oldProperty;
}
- (MyClass *)oldProperty:(MyClass *)oldProperty {
return _newProperty;
}
EDIT: Solution I used with the help of BlackRiders input -------------------------------------------------------------
Interface:
#property (nonatomic, strong) MyClass *newProperty;
- (void)setOldProperty:(MyClass *)oldProperty __attribute__((deprecated));
- (MyClass *)oldProperty __attribute__((deprecated));
Implementation:
- (void)setOldProperty:(MyClass *)oldProperty {
_newProperty=oldProperty;
}
- (MyClass *)oldProperty {
return _newProperty;
}
I would have just one actual property to avoid confusion and name collisions. For example:
property (getter=oldProperty, setter=setOldProperty:) MyClass *newProperty;
You can also optionally create the methods newProperty and setNewProperty:. You can also throw in some #warning statements in the getter and setter you want people to stop using.
Related
I was able to see an interesting case using
Estimote nearables SDK
They have a class ESTNearable with property called zone.
// ENUM
typedef NS_ENUM(NSInteger, ESTNearableZone ) {
ESTNearableZoneUnknown = 0,
ESTNearableZoneImmediate,
ESTNearableZoneNear,
ESTNearableZoneFar,
};
// CLASS
#interface ESTNearable : NSObject <NSCopying, NSCoding>
// ...
#property (nonatomic, assign, readonly) ESTNearableZone zone;
// ...
#end
So when I try to use this method in Swift, compiler fails with that error:
As I understand there is some kind of compiler bug and for some reason it believes that I want to use old zone method from NSObject - (struct _NSZone *)zone OBJC_ARC_UNAVAILABLE; I can use other specific properties of that class without any problems.
As I use an SDK I can not change the name of the zone method. I believe I can write some kind of obj-c category, add some new method there, which will return value of original one, but I do not want to add obj-c classes in my project.
Is there any possibility to call this method from swift as I believe correct zone method will be called for class instances?
Thanks in advance!
Here I found the same question. I answered more deeply there. I could not find something more good, so I went ahead with my old assumptions.
I Added this category to Bridging Header. It worked fine.
#import <EstimoteSDK/EstimoteSDK.h>
#interface ESTNearable (Ex)
/// Solving the compiler problem that "zone" method is unavailable in Swift
#property (readonly) ESTNearableZone nearableZone;
#end
// Implementation
#implementation ESTNearable (Ex)
- (ESTNearableZone)nearableZone
{
return self.zone;
}
#end
After that I just used nearableZone method in Swift
var zone = someNearable.nearableZone
Having an Objective c base class:
#interface ObjcClass : NSObject {
NSString *aVariable_;
}
And a swift sub-class:
class SwiftClass : ObjcClass {
func init() {
// aVariable_ can't be accessed here. An Objective-c derived
// class has direct access to it's super's instance variables!
}
}
How do I access ObjcClass aVariable_ from within SwiftClass?
Great query. We have tried to hard to get this done. The only working solution I found
get value by using self.valueForKey("aVariable_")
set value using self.setValue("New Value", forKey: "aVariable_")
Hope that helps. Possible solution without altering super class.
I couldn't find a "proper" way to do this, but I needed badly for it to work. My solution was to create a simple getter method in my Objective C superclass, like this:
header file
#interface ObjcClass : NSObject {
NSString *myVariable;
}
- (NSString *)myVariable;
in the implementation file
- (NSString *)myVariable {
return myVariable;
}
I'd love to hear of a better way of doing it, but this at least works.
I've searched a lot for this.
Eventually I changed my code from:
#interface PrjRec : NSObject {
#public
NSString* name;
}
#end
To:
#interface PrjRec : NSObject {
}
#property NSString* name;
#end
similar to #JasonTyler solution.
Then I can access to my object property from Swift code with simple dot notation <object instance>.name,
But I needed to change all existing objective-c references from
<object instance>->name
To:
<object instance>.name
or
_name
if inside class unit.
I hope for a better solution too.
This worked as a pretty neat solution for me, just adding a Swift variable like:
var myInstanceVar: String {
return self.value(forKey: "myInstanceVar") as! String
}
If you are willing to have a property, then you can create the property to fit your needs.
#interface ObjcClass : NSObject {
NSString *aVariable_;
}
#property (nonatomic) NSString *aVariable_;
...
#implementation ObjcClass
#synthesize aVariable_ = aVariable_;
This allows the variable to be accessed as inst->aVariable_ or as inst.aVariable_. In the Objective C class the variable can be accessed as aVariable_ or self.aVariable_.
I seriously don't know why anyone does instance variables anymore (for one, they're private by default) vs properties. See Giorgio Calzolato's answer on this (apart from his last line about looking for a better solution - that IS the best solution :) ).
In my case I already had a property and was extra perplexed over why it didn't work. But I realized that the property had a custom time and it needed to be added into my SDK-Bridging-Header.h file.
So if your property is set to a custom type like this:
#property (nonatomic, weak) IBOutlet SDKMyCustomObject *customObject;
...then remember to add it to the bridging header.
I am at my wits end with a property declaration in a iOS class. In my .h file I have the following declaration :
#property (strong, nonatomic)NSString *sessionID;
In my .m file I have this code :
- (void)setSessionID:(NSString *)aSessionID
{
_sessionID = aSessionID;
// Custom code to set this in a global context
}
This is all fine and compiles with no issues. Now I need to have the sessionID return a default value if nothing is set, however the moment I add this line :
- (NSString *)sessionID
{
return _sessionID ? _sessionID : #"defaultSession";
}
then the first line in the setSessionID:
_sessionID = aSessionID;
causes an error with "Use of undeclared function _sessionID. Did you mean aSessionID", I am at my wits end to figure out what is causing it.. I have so many classes with variables and have never seen this before... what is causing this? I restarted Xcode, cleaned out the project and no luck.. If I remove the - (NSString *)sessionID method, then it stops complaining.. but the moment I add the method declaration the Xcode marks it as an error.
Anypointers accepted! :)
Edit: I also noticed, that in this class if I add any property accessor method it complains about the ivar.. e.g. I have another property declared
#property (strong, nonatomic) NSString *userEmail
The moment I add -(NSString *)userEmail, the ivar _userEmail usage above it all becomes undeclared.. :(
If you override both the setter and getter of a property, the compiler will not automatically synthesize the backing ivar for you. You need to do a manual synthesis,
#synthesize sessionID = _sessionID;
I have a block thats stored as an instance variable in a class
typedef void ((^didSelectWord)(NSString* word));
#property (nonatomic,strong) didSelectWord wordSelected;
and i want xcode to auto fillout the block like when you type [UIView animateWithDuration and xcode autocompletes a block for it.
When i autocomplete my block it just fills out
[self.suggestedSearchTermView setWordSelected:(didSelectWord)wordSelected
instead of
[self.suggestedSearchTermView setWordSelected:^(NSString *word) {
Is it possible to change something to make Xcode understand how to autocomplete this block?
Ok I did some testing.
Apparently you have two (far from perfect) options:
avoid the typedef and declare the property as
#property (nonatomic,strong) void (^wordSelected)(NSString * word);
As noted in the comments, this has the drawback of skipping the parameter name in the autocompletion.
explicitly add a setter declaration in the interface
typedef void ((^DidSelectWordBlock)(NSString* word));
#interface YourClass : NSObject
#property (nonatomic,strong) DidSelectWordBlock wordSelected;
- (void)setWordSelected:(DidSelectWordBlock)wordSelected;
#end
this will cause Xcode to resolve the type definition before the setter definition, giving you the nice autocompletion that you would expect. The obvious drawback is the extra setter declaration in the interface.
That said, you should fill in a bug report: http://openradar.appspot.com/
Declare your property without typedef, like this:
#property (nonatomic,strong) void (^wordSelected)(NSString *word);
With this definition Xcode would give you the expansion below:
MyClass *test = [MyClass new];
[test setWordSelected:(void (^)(NSString *))wordSelected];
In exacerbated frustration, I made a macro consolidating this gross process..
#define BlockProperty(SIGNATURE,TYPENAME,varname,Varname) typedef SIGNATURE; #property (nonatomic,copy) TYPENAME varname; - (void) set##Varname:(TYPENAME)_
Now what Previously would've required (for proper autocompletion)..
typedef void(^OnEvent)(BOOL ok,id result);
#property (nonatomic,copy) OnEvent varname;
- (void) setVarname:(OnEvent)_;
is simply
BlockProperty(void(^OnEvent)(BOOL ok, id result),OnEvent,varname,VarName);
QUITE a bit easier, less verbose, AND you get the benefit of the typedef AND and you don't have to create the unsightly, theoretically unneeded setter declaration!
If you WANT to reuse a "type" you'll need another one (which this time will only take THREE parameters (as the block type cannot be redeclared).
#define BlockProp(TYPENAME,varname,Varname) #property (nonatomic,copy) TYPENAME varname; - (void) set##Varname:(TYPENAME)_
BlockProp(OnEvent,anotherVar,AnotherVar);
You could just create a new block type (name) for each property even if their signatures match (using the first macro), but that's kind of gross. Enjoy!
the strangest thing happened. Although I don't think I touched anything in that class, suddenly it started telling me it couldn't find an array in a class...
Here are the errors:
basically it cannot access the mutable array in baseobject (custom Car.h type)
(semantic issue: property objectReadyForCoreDatabase not found in object of type CarPacket (false, because it is declared))
if([baseObject.objectsReadyForCoreDataBaseInput count]<kLenght )
{
}
car packet .h
#import <Foundation/Foundation.h>
#import "ResponsePacket.h"
#interface CarPacket : ResponsePacket
#property (nonatomic, copy) NSString *objectID;
#property (nonatomic, retain) NSMutableArray *objectsReadyForCoreDataBaseInput;
#property (nonatomic, assign) NSInteger timeStamp;
#end
It is weird because on the same page where I get the error if I type object.objectID it recognizes that but not object.objectReadyForCoreDataBaseInput (also it just suddenly stopped working)
Please let me know if you have any ideas... Thank you
I tried restoring to previous snapshots and it had no effect... it still showed the error (even though I know on that date it didn't)
You haven't shared much about the context of where you're making the call (and seeing the error). That said, my guess would be one of two things: The calling class isn't familiar with the receiving class (CarPacket), or, the calling class doesn't know that baseObject is a CarPacket.
Where are you calling from? Make sure the calling class imports the headers. Since I don't know where you're calling from, let's say it's from within UnknownClass:
UnknownClass.m
#import UnknownClass.h
#import CarPacket.h // This should make your class familiar
#implementation UnknownClass
The other thing is that you need to make sure that at the time you're touching the baseObject, your UnknownClass instance knows that it is dealing with a CarPacket instance, e.g.:
- (void)someMethodOfUnknownClass
{
CarPacket *baseObject = (CarPacket *)baseObject; // Cast baseObject if it hasn't been declared as a CarPack in scope...
if([baseObject.objectsReadyForCoreDataBaseInput count]<kLenght )
{
}
}