Is there a simple way to disable a single storyboard scene based on a condition?
I'm using to check if location services are enabled for my app:
[CLLocationManager authorizationStatus] != kCLAuthorizationStatusDenied
If the above is true then I want to disable a scene that I created and the associated segues to get to that scene (I'm using left/right swipe gestures).
** UPDATED: I was confusing multiple storyboards with multiple scenes...my question has been updated to reflect this. I'm wanting to disable a specific scene in my storyboard, not a storyboard.
To do what you want, you should write an action in your view controller that uses the condition(s) you set to choose the scene to segue to (or none at all). Don't just have a button or gesture trigger a push segue -- have it trigger the action in the view controller so that you can select the next scene in your code.
It's all well and good that you can set up segues right in the storyboard file, and it makes a great demo, but when you want to determine the destination scene at runtime you need to do that in code.
I ended up taking a hint from this post: https://stackoverflow.com/questions/8309104/enable-disable-swiper-gesture-or-view-change-in-storyboard
I just created an IBOutlet in the header for a swipe gesture and placed the following code in an if statement that checks if the user has location services enabled or not and wired it up in addition to the segue in IB:
swipe.enable = NO;
Thanks for the assistance all!
Related
I'm trying to implement segueing from a tableview controller when the user taps the cell's accessory button.
I've searched on here and have some new things to try but I just wanted to ask whether in the storyboard you can actually create the segues from the accessory button, or whether you just need to create them from the tableviewcontroller.
It'll be within the accessoryButtonTappedForRowWithIndexPath that I'll want to act on the tap, but I see some answers on here say that you have to just go from the tableviewcontroller when creating your segues where as another answer said that the sender within prepare for segue would be set to the cell that contains your accessory view.
Whenever I try to ctrl drag from the accessory button in my prototype cell it just gets rid of the already existing on-selected segue I'd setup for that cell.
Just wanted to know for sure, what the best practice was before I started making all my detail accessory segues just go from the root TableViewController and passing through accessoryButtonTappedForRowWithIndexPath's indexPath (or it's row) as the sender to my prepareForSegue.
Cheers
Ok, after trying the suggestions I described in my original question I got the code all working how I wanted. I added segues from the root tableview controller and then performed them programatically within the accessoryButtonTappedForRowWithIndexPath delegate function.
I have a few Table View Controllers doing similar things in my navigation controller so I set about implementing this accessory button workflow in each of them. When i reached the last TVC in my nav controller hierarchy I didn't want selecting cells to go any further, so i changed the accessory type to just detail.
As I wasn't concerned at this stage to have the cell interaction sourced segues overwriting each other I just dragged a segue out from the prototype cell to the destination view controller. Upon doing so within the add segue popup I saw 2 options - Selection Segue and Accessory Action. I'm sure that when I first tried doing this I only had the single Selection Segue choice.
Regardless of whether this was my tired eyes missing it, or Xcode having a funny turn (as it seems to from time to time, being laggy at updated states of various files etc) I can now say in answer to my original question, all you have to do is setup your accessory action segue as required. You can have both selection segue and accessory action segues setup from the same prototype cell, and everything just works as you'd expect.
I've just updated my setup to work this way and all seems fine.
Cheers
Playing around with some Objective-C (well, iOS) and have done the following... loaded some UIButtons programmatically into a UIScrollView. That works well. Though I've always just connected UIViewControllers together using control-click and drag. Now I've created buttons programmatically, I have no idea how to go from one view controller to another in a Storyboard because there is nothing to drag from!
I'm not really sure what code to post as such, because I haven't done anything that /nearly/ works or doesn't work as such. I get how to do it with XIBs. But I suppose the question is : 3 UIButtons have been created programmatically and I have 3 UIViewControllers. How do I access those ViewControllers using my UIButtons?
Thanks
In the Interface builder view control click and drag from the viewcontroller icon under the first view controller, to the middle of the second view controller. A segue will be created, selected the appropriate type.
Now select the segue and in the inspector give it a unique identifier (say 'myNewSegue').
Now in your first viewcontroller you can create a method that has the following code:
-(void)myButtonAction:(id)sender {
[self performSegueWithIdentifier:#"myNewSegue" sender:self];
}
And add this method as a target action to your button:
[myButton addTarget:self
action:#selector(myButtonAction:)
forControlEvents:UIControlEventTouchUpInside];]
A segue doesn't have to have a button at the leading end of it; you can instead draw it from an entire view controller to another. You can also give a segue an identifier, a string that's used as a name for that segue. Once you've done that, you can programmatically trigger that segue by calling -performSegueWithIdentifier:sender:.
To actually call -performSegueWithIdentifier:sender:, though, you'll need to connect the button to a target and action. If you've never done that, read the Event Handling Guide for iOS in your documentation.
I have created a project in Xcode using storyboards. I created a segue between two of the view controllers with a button using the click and drag method. However, there are a certain set of conditions that I want to be met in order for the segue to happen. So I already coded the button as an IB action and wrote the conditional code in the implementation file. If the conditions are not met, an alert view pops up, and I don't want the segue to happen. But if the conditions are met then I do want the segue to happen.
Is there any way to programmatically command a segue to happen or not happen inside an IB action function? Or any other way to get the same kind of result?
THANKS! Any help is appreciated!
I found a great solution for this that someone posted... create a segue that originates from from the status bar of the originating view controller, give it an identifier, and then add this code inside the action button:
[self performSegueWithIdentifier:#"identifierName" sender:sender];
Works great!
You can create a custom segue by subclassing UIStoryboardSegue and setting the segue style to "custom" along with your class name in the attributes inspector. Then you can override the perform method in order to see if your conditions are met before you perform the segue. For example
- (void) perform {
if (...) {
[[self sourceViewController] presentModalViewController:[self destinationViewController] animated:YES];
}
}
See also the documentation http://developer.apple.com/library/IOs/#featuredarticles/ViewControllerPGforiPhoneOS/CreatingCustomSegues/CreatingCustomSegues.html
Alternatively, you could disable the button as long as your conditions are not met. Maybe that's the better approach, since then the user has a visual indication that the segue won't happen, instead of getting a negative feedback after pressing the button.
Is there a way to use custom segues to individually animate several different subviews.
For example, I want my modal view to appear by the UINavigationBar fading in (as the source destination's UINavigationBar fades out) and then a UITableView to slide down the screen 'over' the source destination's view controller.
When I try to implement this in the - (void)perform method. My properties don't animate using [UIView animateWithDuration: animations: completion:].
Can anyone provide me with a solution?
Thanks in advance!
You can certainly use custom segues to achieve this - however, I don't think you'll get much help without more details about the setup of your view controllers.
Everything you describe is correct: to create a custom segue you animate the views inside your sourceViewController and destinationViewController inside the segue's perform: method. If they're not animating you might want to check that your segue is actually getting called (you can use breakpoints in the debugger to check this), or that the views you're trying to access inside your view controllers actually exist at that point in time (again, something you can check using the debugger).
For a solution specific to your app you're almost certainly going to have to provide more details about the two view controllers you're trying to transition between. Perhaps you could post your perform: method.
I'm having trouble to achieve the following using a storyboard:
When setup is not done:
run app -> show settings view controller -> show main navigation controller
When setup is done:
run app -> show main navigation controller
So basically, I want the app to programmatically start with the settings view in certain cases, and otherwise skip right ahead to the main navigation controller.
I did manage to show the settings view with a modal style segue from the main navigation controller, but I don't know how to display it before the main navigation controller is displayed. Any ideas?
By default, the initial view controller from your main storyboard is instantiated and displayed automatically when your app starts up. To prevent this happening you need to remove the UIMainStoryboardFile setting from your info.plist file.
With no default view controller, you are now free to create one programmatically at app startup. See the UIStoryboard documentation. Use +storyboardWithName:bundle: to load the storyboard and then use –instantiateViewControllerWithIdentifier: to create the correct view controller. You will also need to create a main UIWindow and add the view controller's view to it just like you used to do with .nib based UI. Note that without the UIMainStoryboardFile setting a main window is not created for you - read the explanation.
I managed to do it a bit different:
Use a UINavigationController as the initial view controller.
Create a root view controller that will manage the decision of what to load.
Create a Storyboard Segues from the root view controller to the main view and to settings view, and give the segues proper identifiers.
Call the performSegueWithIdentifier with the proper identifier from your root view controller.
Just another solution, hope this helps.
I did something similar to amoshaviv, his advice is sound. I did it slightly different though, and I'll give some more info.
I created a custom MyInitialViewController class, derived from UIViewController, and made this the initial view controller.
In the storyboard file, I created modal segues with appropriate names to all (in my case three) possible 'real' first view controllers.
In the MyInitialViewController class, I implemented the
- (void)viewDidAppear:(BOOL)animated;
method, to first perform the check which view to switch to, and then do the correct
[self performSegueWithIdentifier:#"NameOfSegue" sender:self];
Effectively, this makes the MyInitialViewController nothing more than a switch performed when it's brought into view. I first tried doing this when loaded because I don't care for actually seeing this view, but that did not work, while viewDidAppear does.
To make this visually smooth, I tried the following. In the properties of the segues, I disabled animation. The view I left empty, and I gave it a background color matching to that of the startup image.