In Objective C / iOS;
We have a process similar to this (set up in xcode storyboard);
Menu View Controller -> Enter in a code -> Process/Validate -> Present a Failed Code page
The (->) arrows signify a push segue setup in storyboard
When in failed state I want to pop to the Enter in a code view controller.
UIViewController *vc = nil;
NSUInteger index=0;
for (UIViewController *viewController in self.navigationController.viewControllers) {
if ([viewController isKindOfClass:[SomeViewController class]]) {
vc = viewController;
break;
}
index++;
}
if (vc) {
dispatch_async(dispatch_get_main_queue(), ^(void) {
[self.navigationController popToViewController:vc animated:YES];
});
return;
}
This pops me back to the VC I want to go to.
Except now when I press a submit on the Enter code page it does 3 or 4 more "pushes", when it should only be 1.
Do I need to unwind the segue? I tried emptying the navigational view controller stack, and I even tried ridding it of its last active view controller -- both of these return a blank or black window view frame.
Why would popping a view controller in the navigation stack affect the segues in my view controller to the point where whenever I try to do a push segue action it will try to push multiple view controllers onto the stack?
Turns out I had the following issue
Button press causes segue action in storyboard
I did the same segue action in code on the button, hence pushing multiple times
I have now solved this issue
Related
I have looked around but haven't found a satisfying answer. My problem is that whenever I call popToRootViewControllerAnimated:(BOOL) it is not doing anything. When I NSLog it, it logs (null).
Let me back up a bit here. I have a table view controller that has a list of things, at the navigation bar up top there is an option to add and that takes me to a new view controller with a segue "Present as PopOver" which gets rid of the principal or main navigation bar. So I made one manually and added 2 bar button items "Cancel" and "Add". When "Cancel" is tapped, it should take the user back to the table view controller and discard changes, when "Add" button is tapped, it should also take user back to the previous table view controller with the changes. But it's not doing anything.
Here is my code.
- (IBAction)cancelButton:(UIBarButtonItem *)sender {
UINavigationController * navigationController = self.navigationController;
NSLog(#"%#", navigationController);
NSLog(#"cancel tapped though");
ListingTableViewController *rootController = [[ListingTableViewController alloc] init];
[navigationController popToRootViewControllerAnimated:NO];
[navigationController pushViewController:rootController animated:YES];
}
As far as the segue, this view controller is not connected to anything, or should I connect it? This is a noobish question indeed. Here is my xcode screenshot.
Check this link for the screenshot of the storyboard
http://i.stack.imgur.com/lqnCF.png
You must call
- (IBAction)cancelButton:(UIBarButtonItem *)sender {
NSLog(#"cancel tapped though");
[self dismissViewControllerAnimated:YES completion:nil];
}
instead of popToRootViewControllerAnimated because your VC presented and not pushed!
When presenting a view, you are not pushing it in your navigation controller, but having it presented. To dismiss it, try using [self.presentingViewController dismissViewControllerAnimated:NO completion:nil].
I use custom transitions for modal segue, implemented using UIViewControllerAnimatedTransitioning delegate. All segues setup via Storyboard.
I have two nav controllers, both have single root VC setup. Let's call them 1st NVC, 1st VC, 2nd NVC and 2nd VC.
1st VC adopts the UIViewControllerAnimatedTransitioning protocol, implementation simply returns animator:
- (id <UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source {
return [ModalTransitionAnimator new];
}
- (id <UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed {
return [ModalTransitionAnimator new];
}
When any segue happens from 1st VC -> 2nd NVC, 1st VC catches the event in prepareForSegue: and assigns transitioningDelegate along with modalPresentationStyle because you cannot do that from IB:
UINavigationController* destination = (UINavigationController*)segue.destinationViewController;
destination.transitioningDelegate = self;
destination.modalPresentationStyle = UIModalPresentationCustom;
So everything seems fine, I get a very cool animation running, destination controller shows up, all viewWillAppear: and viewDidAppear: fire in the right order.
And so now on screen, I have 2nd NVC with 2nd VC inside.
I tap "Cancel" button in Navigation bar, unwind action triggers on 1st VC, but no backward animation happening. I mean in fact 2nd VC is still on screen.
So apparently nobody calls dismissViewControllerAnimated. I suppose Storyboard is confused and can't find the way back because 2nd NVC was initially modally presented and then some other controller requests unwinding. How do you deal with that normally?
I followed the unwind chain and found that UIKit was not able to find the right unwind segue after state restoration. Before state restoration everything worked perfectly fine.
I fixed it manually and traversed my controllers hierarchy to return a controller that has unwind action defined:
- (UIViewController*)viewControllerForUnwindSegueAction:(SEL)action fromViewController:(UIViewController *)fromViewController withSender:(id)sender {
if([NSStringFromSelector(action) hasPrefix:#"unwindToInitialViewController"]) {
return [[((UINavigationController*)self.centerViewController) viewControllers] firstObject];
}
UIViewController* c = [super viewControllerForUnwindSegueAction:action fromViewController:fromViewController withSender:sender];
DDLogInfo(#"%s = %#, c = %#", __PRETTY_FUNCTION__, NSStringFromSelector(action), c);
return c;
}
I'm starting to work on an ipad application that would require activity (or functions) on the detail view and would push (or transfer) to another view controller depending on the button tapped.
Trying to figure out if segue is what I'm supposed to be using with this.
My storyboard looks like this:
SplitViewController -> navigationcontroller(master view) / login
(detail view) -> dashboard (will be transferred on successful login
But whenver I tap the button and successfully login it would give me this error:
Push segues can only be used when the source controller is managed by
an instance of UINavigationController.'
Thoughts?
EDIT: Code that pushes to the next viewcontroller
- (IBAction)btnSubmit:(id)sender {
User *user = [[User alloc] init];
user.email = self.txtEmail.text;
user.rawPassword = self.txtPassword.text;
if(user.isValid){
[self performSegueWithIdentifier:#"LoginSuccess" sender:self];
}
}
The error is telling you that you are using the option push without embedding a navigation controller. If you don't want to use navigation controller just click on the segue connection in storyboard and change it to modal and it will move the views without error.
This seems to be the patten used throughout Apples applications; Creation of a new record is done through a modal View which needs to be saved or canceled to continue, and editing a record is done through a view pushed onto the navigation stack.
It doesn't seem right to be basically duplicating my ViewController for 'add' and 'edit' but there are several differences in how pushed and modal ViewControllers work which complicate things.
How should I be doing this so it can cover both bases?
-
Differences include.
When pushed onto the stack the navBar appears at the top of the View and can be configured to contain the cancel/save buttons. When presented modally this is not the case so to duplicate the interface a toolbar needs to be created separately and close/save buttons added to this instead.
When dismissing a pushed view we send a message to the navigation controller [self.navigationController popViewControllerAnimated:YES];, when dismissing a modal view we send a message to self [self dismissModalViewControllerAnimated:YES];
You could add the UIToolbar in InterfaceBuilder, and then just hide it in viewDidLoad when self.navigationController is not nil.
As for dismissing, you could have something like:
- (void)didCancel {
[self.navigationController popViewControllerAnimated:YES] || [self dismissModalViewControllerAnimated:YES];
}
This will shortcircuit if your viewcontroller is part of a navigationcontrol, and use dismissModalViewControllerAnimated otherwise.
This should work for your cancel button. For your save button, it is useful to call some sort of delegate method such as:
- (void)didSave {
// do your saving juju here
if([self.delegate respondsToSelector:#selector(viewController:didSave:]) {
[self.delegate viewController:self didSave:whatJustGotSaved];
}
[self.navigationController popViewControllerAnimated:YES]; // noop if currently modal
}
In the delegate's implementation then, you can put:
- (void)viewController:(UIViewController*)viewController didSave:(NSObject*)whatJustGotSaved {
// do stuff with parameters
[self.modalViewController dismissModalViewControllerAnimated:YES]; // noop if not modal
}
I have the next question:
In my project I have the next:
UItabbarController
....Some UINAvigationControllers....
*(1) UINavigationController
UIViewController (UItableView) - When select one row it goes to...(by push) to:
UIViewController (UItableView) - And here the same than before, for each row i open a new tableview....
My problem is when i click in the tab bar item, I see the viewController view like last time that i saw this, and no reload to the *(1) first view another time( like i would like)
Where I need to write sth for each time that i click in a tab bar item i reload the first view of this tab bar item.
PD: I have the call: [theTableView reloadData]; in method "viewWillAppear".
The thing I'm doing is:
In my navigation Controller I have a View Controller (like tableview) and when i click in one row, in the "didSelectRowAtIndexPath" method I create another View Controller calling "myController" and i push this element like this ( [[self navigationController] pushViewController:myController animated:YES];)
And this for each time i click in one row in the next tables.
Then I think the problem is not to reload the table view in the method viewWillAppear, it's to take out from the screen the next views controller that I inserted to the root one.
I'm rigth?
IN RESUME:
My app has the next:
Tab bar to move between screens
Navigation inside each tab bar (as far as you want), why? because all the tabBarItems show Tables, and if you click in one row you open another table,.....
My problem then is that I would like to come back to the 1st Main table when i click in the tab bar. For the moment the app doesn't do this, it continue in the scree(table view) that was the last visit in this tab. (Is not completely true, because if i click two time, Yes, it comes back but don't enter in the "viewWillLoad" or "didSelectViewController" methods, because i made NSLogs and it doesn't show them).
The sketche can be this:
AppDelegate -> WelcomeScreen ->VideosTableViewController ->RElatedVideosTableViewController -> ..... ..... ....
The 1st thing is to show the Welcome screen (not so important, only some buttons) and in this class i have the TabBArController initialized with "localViewControllersArray" that is a NSMutableArray of NavigationControllers each initialized with one ViewController .
Then when i press one of the buttons in this welcome Screen i sho the tab bar Controller (Shows the VideosTableViewController)
In the next step, when I click in one row, in "DidSelectRowAtIndexPath" I create a RElatedVideosTableViewController, and I push this by "[[self navigationController] push....: "The relatedvideo table view i create" animated:YES];
AND I ALSO HAVE:
Add: UITabBarControllerDelegate
Add:
(void)tabBarController:(UITabBarController*)tabBarController
didEndCustomizingViewControllers:
(NSArray*)viewControllers
changed:(BOOL)changed { }
(void)tabBarController:(UITabBarController*)tabBarController
didSelectViewController:(UIViewController*)viewController
{ if ([viewController
isKindOfClass:[UINavigationController
class]])
{ [(UINavigationController *)viewController popToRootViewController:NO];
[theTableView reloadData];
NSLog(#"RELOAD");
} }
And at the initialization of the class:
[super.tabBarController setDelegate:self];
But in the console I don't see the NSLog I'm making then is not going in this method.
Make your app delegate the tab bar controller's delegate, either in Interface Builder or in code:
- (void)applicationDidFinishLaunching
{
...
self.tabBarController.delegate = self;
}
Then, when the tab bar switches to a different view, you get notified, at which point you pop to the root of the selected nav controller thus:
- (void)tabBarController:(UITabBarController *)tabBarController didSelectViewController:(UIViewController *)viewController
{
if ([viewController isKindOfClass:[UINavigationController class]])
{
[(UINavigationController *)viewController popToRootViewController:NO];
}
}
Each view controller should have its own table view, so I don't know what you are trying to do by the reload.