Passing NSLocalizedString as a parameter - objective-c

Question

I have a class MyOperation that has a property localizedTitle that should return a localized title but the title is being set from outside:
#interface MyOperation
- (instancetype)initWithTitle:(NSString*)title;
#property (readOnly) NSString *localizedTitle;
#end
#interface PTImageOperationSession() {
NSString* _operationTitle;
}
#implementation MyOperation
- (instancetype)initWithTitle:(NSString*)title
{
[self retainSelf];
self = [super init];
if (self)
{
_operationTitle = title;
}
return self;
}
- (NSString *)localizedTitle {
return _operationTitle;
}
#end
- (void)foo {
MyOperation *operation = [[MyOperation alloc] initWithTitle:NSLocalizedString(#"MyLocalizedTitle", nil)]; // Good.
NSSting *titleString = [self titleString]; // Can be different strings at runtime.
MyOperation *operation1 = [[MyOperation alloc] initWithTitle: titleString]; // Bad because the title is not localized.
}
Question: Is it possible to insure that the class will always be initialised with localised title? My responsibility as a class owner is to return a localized title, but it is being set from outside so I have no control on it. Would you tag it as a "design issue"?

Answer 1

Passing variable to NSLocalizedString macro shouldn't be any problem, here is what I did for testing purpose:
Localizable.strings
"MyString"="My sample localized string";
And my TestClass
#interface TestClass : NSObject
#property (readonly) NSString *localizedTitle;
-(instancetype)initWithTitle:(NSString *)title;
#end
#implementation TestClass {
NSString *_title;
}
-(instancetype)initWithTitle:(NSString *)title {
self = [super init];
if (self) {
_title = NSLocalizedString(title, nil);
}
return self;
}
-(NSString *)localizedTitle {
return _title;
}
#end
Init my test class, then access its property
TestClass *myClass = [[TestClass alloc] initWithTitle:#"MyString"];
NSLog(#"%#", myClass.localizedTitle);
This is what I have in console:
2018-11-05 19:16:36.268393 TestApp[1471:352553] My sample localized string
Update
The macro:
#define NSLocalizedString(key, comment) \
[NSBundle.mainBundle localizedStringForKey:(key) value:#"" table:nil]
Is the shortcut to localizedStringForKey:value:table: function & according to the document:
Return Value
A localized version of the string designated by key in
table tableName. This method returns the following when key is nil or
not found in table:
If key is nil and value is nil, returns an empty string.
If key is nil and value is non-nil, returns value.
If key is not found and value is nil or an empty string, returns key.
If key is not found and value is non-nil and not empty, return value.
If you pass a non-existence key to the macro, you will receive the key itself. That's the designated behavior.
By the way, in common sense, you can't ask for a localized string if it isn't defined, right?