Is there any way define a object in a method, call a method of another object, and in that method use the first object:
-(IBAction)method{
class * instance = [[class alloc] initWithValue:value];
[instance method];
}
The method defined in class.m file:
-(void) method {
instance.value = someOtherValue;
}
The simple solution is to pass it in as a parameter:
[instance method:self];
...
- (void) method:(class *)caller { ...
To avoid coupling the two classes together too tightly, however, it is common to use a protocol to define the semantics of the callback, and to separate the method-call from the specification of the callback handler by assigning a delegate first, then calling methods. It's a bit involved, and I hope I have correctly covered all the details.
// Foo.h
@class Foo;
@protocol FooDelegate
- (void)doSomethingWithFoo:(Foo*)caller;
@end
@interface Foo {
id<FooDelegate> delegate;
}
@property (nonatomic, retain) id<FooDelegate> delegate;
- (void)method;
@end
// Foo.m
@implementation Foo
@synthesize delegate;
- (void)method {
[delegate doSomethingWithFoo:self];
}
@end
// Bar.h
#import "Foo.h"
@interface Bar<FooDelegate> {
}
// Bar.m
@implementation Bar
- (IBAction)method {
Foo *foo = [[Foo alloc] init...];
foo.delegate = self;
[foo method];
}
- (void)doSomethingWithFoo:(Foo*)caller {
NSLog(@"Callback from %@", caller);
}
@end
valueandsomeOtherValue?