Handling an iOS login segue - ios

Question

Step by step how would I segue a user after authentication seen below?
//curent code in viewcontroller2.h
-(IBAction)btnLoginRegisterTapped:(UIButton*)sender {
//form fields validation
if (fldUsername.text.length < 4 || fldPassword.text.length < 4) {
[UIAlertView error:#"Enter username and password over 4 chars each."];
return;
}
//salt the password
NSString* saltedPassword = [NSString stringWithFormat:#"%#%#", fldPassword.text, kSalt];
//prepare the hashed storage
NSString* hashedPassword = nil;
unsigned char hashedPasswordData[CC_SHA1_DIGEST_LENGTH];
//hash the pass
NSData *data = [saltedPassword dataUsingEncoding: NSUTF8StringEncoding];
if (CC_SHA1([data bytes], [data length], hashedPasswordData)) {
hashedPassword = [[NSString alloc] initWithBytes:hashedPasswordData length:sizeof(hashedPasswordData) encoding:NSASCIIStringEncoding];
} else {
[UIAlertView error:#"Password can't be sent"];
return;
}
//check whether it's a login or register
NSString* command = (sender.tag==1)?#"register":#"login";
NSMutableDictionary* params =[NSMutableDictionary dictionaryWithObjectsAndKeys:command, #"command", fldUsername.text, #"username", hashedPassword, #"password", nil];
//make the call to the web API
[[API sharedInstance] commandWithParams:params onCompletion:^(NSDictionary *json) {
//result returned
NSDictionary* res = [[json objectForKey:#"result"] objectAtIndex:0];
if ([json objectForKey:#"error"]==nil && [[res objectForKey:#"IdUser"] intValue]>0) {
[[API sharedInstance] setUser: res];
//this doesn't dismiss anything; its leftover from another tutorial =)
[self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
//show message to the user
[[[UIAlertView alloc] initWithTitle:#"Logged in" message:[NSString stringWithFormat:#"Welcome %#",[res objectForKey:#"username"]] delegate:nil cancelButtonTitle:#"Close" otherButtonTitles: nil] show];
} else {
//error
[UIAlertView error:[json objectForKey:#"error"]];
}
}];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
Would connecting a sufficient segue on the storyboard and putting this above didrecievememory warning suffice or no?
if (![[API sharedInstance] isAuthorized]) {
[self performSegueWithIdentifier:#"ShowLogin" sender:nil];
}
How does one go about creating segues from the storyboard ? I've seen these 3 links but still need a firm answer in creating a segue after a login. Custom segue after successful login http://www.raywenderlich.com/50308/storyboards-tutorial-in-ios-7-part-1 https://developer.apple.com/library/ios/featuredarticles/ViewControllerPGforiPhoneOS/CreatingCustomSegues/CreatingCustomSegues.html

Answer 1

performSegueWithIdentifier is correct. You need to make sure you execute this on the main thread -
NSString* command = (sender.tag==1)?#"register":#"login";
NSMutableDictionary* params =[NSMutableDictionary dictionaryWithObjectsAndKeys:command, #"command", fldUsername.text, #"username", hashedPassword, #"password", nil];
//make the call to the web API
[[API sharedInstance] commandWithParams:params onCompletion:^(NSDictionary *json) {
//result returned
NSDictionary* res = [[json objectForKey:#"result"] objectAtIndex:0];
if ([json objectForKey:#"error"]==nil && [[res objectForKey:#"IdUser"] intValue]>0) {
[[API sharedInstance] setUser: res];
dispatch_async(dispatch_get_main_queue(),^{
[self performSegueWithIdentifier:#"someIdentifier" sender:self];
});
} else {
//error
[UIAlertView error:[json objectForKey:#"error"]];
}
}];
You will need to make sure "someIdentifier" is the identifier of the segue in your login scene to your next scene. To create the segue, ctrl drag from your View Controller icon in your login scene to the destination scene and give the segue an identifier.
You only need to create a custom segue if you want to alter the visual appearance of the segue.