how to replace a method name based on condition in swift?

Question

is there any way to just replace a method name with another method name based on conditions in swift2.2?

example:

 if(self.RecivedString == "varMethod"){
     self.routes.varMethod(postData, andCompletionHandler: { (response, error) in
                if(error.length == 0){
                    if(response.valueForKey("status") as! NSInteger == 1){

                        self.performSelectorOnMainThread(#selector(SubmitViewController.navigateToSubmissionViewController), withObject: nil, waitUntilDone: true)
                    }else{
                        self.showalert(response.valueForKey("msg") as! String)
                    }


                }else{
                    self.showalert(error as String)
                }
            })


  }  

in the above example i want to replace self.routes.varMethod name with other self.routes.varMethodNew name base on conditions.

Answer 1

You cannot replace a method name with another method name , but you can have a closure variable to hold a reference to the methods.

Assuming you have two classes like this:

class Routes {
    typealias CompletionHandler = ([String: AnyObject], NSError?)->Void
    func varMethod(data: NSData, andCompletionHandler: CompletionHandler) {
        //...
    }
    func varMethodNew(data: NSData, andCompletionHandler: CompletionHandler) {
        //...
    }
}

class SubmitViewController: UIViewController {
    var routes: Routes = Routes()
    var recievedString: String?
    func showAlert(message: String) {/*...*/}
    func navigateToSubmissionViewController() {/*...*/}
    //...
}

You can write some method using the closure variable in your SubmitViewController as:

func someMethod(postData: NSData) {
    //Declare a closure variable
    let theMethod: (NSData, andCompletionHandler: Routes.CompletionHandler)->Void //<-Make this match to `varMethod` and `varMethodNew`.
    if self.recievedString == "varMethod" {
        theMethod = self.routes.varMethod
    } else {
        theMethod = self.routes.varMethodNew
    }
    //And call it
    theMethod(postData, andCompletionHandler: { response, error in
        if error == nil {
            if response["status"] as! Int == 1 {
                dispatch_async(dispatch_get_main_queue()) {
                    self.navigateToSubmissionViewController()
                }
            } else {
                self.showAlert(response["msg"] as! String)
            }
        } else {
            self.showAlert(error!.localizedDescription)
        }
    })
}

---

But in your case, you can define the completion handler as a closure variable:

func someOtherMethod(postData: NSData) {
    //Declare a closure variable
    let completionHandler: Routes.CompletionHandler = { response, error in
        if error == nil {
            if response["status"] as! Int == 1 {
                dispatch_async(dispatch_get_main_queue()) {
                    self.navigateToSubmissionViewController()
                }
            } else {
                self.showAlert(response["msg"] as! String)
            }
        } else {
            self.showAlert(error!.localizedDescription)
        }
    }
    //And use it
    if self.recievedString == "varMethod" {
        self.routes.varMethod(postData, andCompletionHandler: completionHandler)
    } else {
        self.routes.varMethodNew(postData, andCompletionHandler: completionHandler)
    }
}