Type Method


Dynamically provides an implementation for a given selector for an instance method.


class func resolveInstanceMethod(_ sel: Selector!) -> Bool



The name of a selector to resolve.

Return Value

true if the method was found and added to the receiver, otherwise false.


This method and resolveClassMethod(_:) allow you to dynamically provide an implementation for a given selector.

An Objective-C method is simply a C function that take at least two arguments—self and _cmd. Using the class_addMethod(_:_:_:_:) function, you can add a function to a class as a method. Given the following function:

void dynamicMethodIMP(id self, SEL _cmd)
    // implementation ....

you can use resolveInstanceMethod: to dynamically add it to a class as a method (called resolveThisMethodDynamically) like this:

+ (BOOL) resolveInstanceMethod:(SEL)aSEL
    if (aSEL == @selector(resolveThisMethodDynamically))
          class_addMethod([self class], aSEL, (IMP) dynamicMethodIMP, "v@:");
          return YES;
    return [super resolveInstanceMethod:aSel];

Special Considerations

This method is called before the Objective-C forwarding mechanism is invoked. If responds(to:) or instancesRespond(to:) is invoked, the dynamic method resolver is given the opportunity to provide an IMP for the given selector first.

See Also

Dynamically Resolving Methods

class func resolveClassMethod(Selector!) -> Bool

Dynamically provides an implementation for a given selector for a class method.

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