Swift Language Method Swizzling Basics of Swift Swizzling
Example
Let's swap the implementation of methodOne() and methodTwo() in our TestSwizzling class:
class TestSwizzling : NSObject {
dynamic func methodOne()->Int{
return 1
}
}
extension TestSwizzling {
//In Objective-C you'd perform the swizzling in load(),
//but this method is not permitted in Swift
override class func initialize()
{
struct Inner {
static let i: () = {
let originalSelector = #selector(TestSwizzling.methodOne)
let swizzledSelector = #selector(TestSwizzling.methodTwo)
let originalMethod = class_getInstanceMethod(TestSwizzling.self, originalSelector);
let swizzledMethod = class_getInstanceMethod(TestSwizzling.self, swizzledSelector)
method_exchangeImplementations(originalMethod, swizzledMethod)
}
}
let _ = Inner.i
}
func methodTwo()->Int{
// It will not be a recursive call anymore after the swizzling
return methodTwo()+1
}
}
var c = TestSwizzling()
print(c.methodOne())
print(c.methodTwo())
