iOS Push Notification to open next tab?

[Danneman101]

I've got a tabbed application that uses Push Notifications (PN).

Whenever a PN is received, I want it to automatically open tab 2 (index 1), both if the app is opened or not.

For this I intercept the PN in AppDelegate.m>didReceiveRemoteNotification, and call the "OpenEventTab" in FirstViewController:

AppDelegate.m

...
#import "FirstViewController.h"
...
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo 
{  
    FirstViewController *firstView = [[FirstViewController alloc] init];
    [firstView OpenEventTab];
    NSLog(@"OpenEventTab called");
}

FirstViewController.m

- (void)OpenEventTab
{   
    self.tabBarController.selectedIndex = 1;
    NSLog(@"OpenEventTab executed");
}

Using NSLog I've realized that the "OpenEventTab"-method is in fact called each time a PN is received, but despite this the next tab is not opened.

Calling the "OpenEventTab" from a button from within FirstViewController does however show that the function does indeed work, and promptly opens the next tab.

So you can probably appreciate why I'm a bit confused at this behavior. Does anybody have an explanation and hopefully a solution to this?

Thanks,
Dan

 

[dejo]

You sure you want to be creating a new instance of FirstViewController when you receive your remote notification?

 

[Danneman101]

Oh, that's right, I should be calling the existing class like so:

AppDelegate.m

...
#import "FirstViewController.h"
...
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo 
{  
    [B][(FirstViewController*)self OpenEventTab];[/B]
    NSLog(@"OpenEventTab called");
}

Problem is now I run into an NSInvalidArgumentException instead:
-[AppDelegate OpenEventTab]: unrecognized selector sent to instance 0x154dd0

I exposed this method to other classes accordingly:

FirstViewController.h

#import <UIKit/UIKit.h>
@interface FirstViewController : UIViewController
[B]-(void) OpenEventTab;[/B]
@end

That should be enough, shouldn't it?

Thanks,
Dan

 

[dejo]

Oh, that's right, I should be calling the existing class like so:

Well, not exactly like so.

AppDelegate.m

...
#import "FirstViewController.h"
...
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo 
{  
    [B][COLOR="Red"][(FirstViewController*)self OpenEventTab];[/COLOR][/B]
    NSLog(@"OpenEventTab called");
}

self is not of type FirstViewController when you're in AppDelegate, is it? It's of type AppDelegate.

Show the code where you instantiate your FirstViewController in AppDelegate (probably within your application:didFinishLaunchingWithOptions:)

 

[Danneman101]

Oh...

Well, that's the thing, I just started a new project using the Tabbed Application template (w. storyboard) for the first time, and the AppDelegate doesn't seem to display the code that instantiates the FirstViewController (which is one of the tabs).

Here's the full code in AppDelegate (using parse.com's code for PN's btw).

AppDelegate.h

#import <UIKit/UIKit.h>
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@end

AppDelegate.m

#import "AppDelegate.h"

// PUSH NOTIFICATION (parse.com) 
#import "Parse/Parse.h"

#import "FirstViewController.h"

@implementation AppDelegate

@synthesize window = _window;


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    
    // PUSH NOTIFICATION (parse.com) 
    // Register:    for push notifications
    [application registerForRemoteNotificationTypes:UIRemoteNotificationTypeBadge|
     UIRemoteNotificationTypeAlert|
     UIRemoteNotificationTypeSound];
    
    return YES;
}


// PUSH NOTIFICATION (parse.com) 
// Send:    device token to parse.com
- (void)application:(UIApplication *)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)newDeviceToken
{
    // Tell Parse about the device token.
    [PFPush storeDeviceToken:newDeviceToken];
    // Subscribe to the global broadcast channel.
    [PFPush subscribeToChannelInBackground:@""];
}


// PUSH NOTIFICATION (parse.com) 
// Show:    notification UI if in-app
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo 
{
    [PFPush handlePush:userInfo];
    
    // OPEN EVENTS TAB (TAB 2)
    [B][(FirstViewController*)self OpenEventTab];[/B]
}


@end

There's really no instantiation code of FirstViewController there. The full code for FirstViewController is simply:

FirstViewController.h

#import <UIKit/UIKit.h>
@interface FirstViewController : UIViewController
[B]-(void) OpenEventTab;[/B]
@end

FirstViewController.m

#import "FirstViewController.h"

// PUSH NOTIFICATION (parse.com) 
#import "Parse/Parse.h"

@implementation FirstViewController
...

// PUSH NOTIF. (parse.com)
// Open:    Second tab
// From:    AppDelegate.m > didReceiveRemoteNotification
[B]- (void)OpenEventTab
{   
    self.tabBarController.selectedIndex = 1;
    NSLog(@"OpenEventTab in FirstView");
}[/B]

...

@end

Perhaps I need to add a UIViewController-object in AppDelegate using IBOutlet, and link that via the Storyboard (much like you would do in a regular nib)? But how do I outlet an object from the AppDelegate when it doesn't have a representative object in the Storyboard?

I tried to do the following but no such outlets appeared anywhere in the storyboard. At least with the old nib-files you'd have an object called AppDelegate that displayed these outlets...

AppDelegate.h

..
#import "FirstViewController.h"
@interface AppDelegate : UIResponder <UIApplicationDelegate>
{
	IBOutlet FirstViewController		*firstVC;
}
@property (nonatomic, retain) FirstViewController *firstVC;
..

 

[jnoxx]

Not read your last post, but, you can search for your FirstViewController in the view hiearchy of yourself. Then (what I would do), is set a pointer to that object, and then call the method on it, that's how we do it with our PN's too.
Not creating new instances.

 

[Danneman101]

Not read your last post, but, you can search for your FirstViewController in the view hiearchy of yourself. Then (what I would do), is set a pointer to that object, and then call the method on it, that's how we do it with our PN's too.
Not creating new instances.

Even doing a search I can't find where FirstViewController gets instantiated in AppDelegate.

I tried adding an outlet for a FirstViewController in the AppDelegate as I would normally do in a xib-file (this project uses storyboard):

AppDelegate.h

..
#import "FirstViewController.h"
@interface AppDelegate : UIResponder <UIApplicationDelegate>
{
	IBOutlet FirstViewController		*firstVC;
}
@property (nonatomic, retain) FirstViewController *firstVC;
..

But it seems I can't outlet an object from the AppDelegate since the AppDelegate it doesn't have a representative object in the Storyboard? Did they remove that object in storyboard? If so, how do I connect the "firstVC" outlet in AppDelegate.h to the FirstViewController?

[edit]
Not finding any info about this I tried adding a new object to the storyboard and setting it as an AppDelegate-object (setting Custom Class > Class). I placed this object in the FirstViewController, and linked the outlet firstVC to the FirstViewController-object.

However, when sending a PN, the same error halted the app.

 

[Danneman101]

Well, it seems this storyboarding-business is pretty new to even the more adept, and I've found very little info on how to call methods in another already instantiated class from AppDelegate. I've tried every option to the limits of my limited knowledge, but to no avail.

So I finally resorted to creating a new project NOT using that infernal storyboard (which if it wasn't for this apparent restriction would be quite nice to use), and of course it works without any problems.

Anyway, thanks for trying to help solve the issue, I really appreciate it

I'm still curious as to how to solve this with storyboards. I think I'll post a new thread with only that question since this thread has become overly convoluted and it is highly likely that nobody will ever read it. Hope I'm not breaking the forum rules doing so.

Cheers,
Daniel

 

[chown33]

I'm still curious as to how to solve this with storyboards.

Maybe it's not possible with storyboards. Frankly, I don't understand the problem you're trying to solve, but I didn't wade through all the posted code, either.


I googled for:
storyboard root view controller site:developer.apple.com

and came up with this:
http://developer.apple.com/library/...cellaneous/RN-AdoptingStoryboards/_index.html

Under the heading "Accessing the First View Controller" it says:

"The application delegate is not represented in the storyboard. If you need to access the first view controller ..."
​

So it might be worth spending some time going through the storyboard docs again, maybe more carefully, and seeing if you missed anything. If there is a problem with Apple's docs, there's a link at the bottom of every page for sending feedback to Apple. It says "Did this document help you?" and offers 3 choices.

 

[Danneman101]

Thanks for the input. Well, to boil it down I'm simply trying to expose an IBOutlet of the type FirstViewController (name of my other class) in AppDelegate so that I can reference that class from AppDelegate. Can't really figure out how to do that using storyboards :/

 

[dejo]

Thanks for the input. Well, to boil it down I'm simply trying to expose an IBOutlet of the type FirstViewController (name of my other class) in AppDelegate so that I can reference that class from AppDelegate. Can't really figure out how to do that using storyboards :/

That document chown33 linked to explains exactly how to get a reference to FirstViewController. You don't need it to be an IBOutlet.

And there are other ways to achieve what you need. NSNotifications come to mind.

 

[Danneman101]

I tried the suggested method in the documents, but get the same "unrecognized selector sent"-error.

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo 
{
    // Show:    Push Notification
    [PFPush handlePush:userInfo];
    
    // Call:  Function in SecondViewController
    UINavigationController *rootNavigationController = (UINavigationController *)self.window.rootViewController;
    SecondViewController *SecVC = (SecondViewController *)[rootNavigationController topViewController];
    [SecVC.myTableView reloadData];
}

The error reads:
"NSInvalidArgumentException', reason: '-[UITabBarController topViewController]: unrecognized selector sent to instance 0x14bc80"

Any ideas?

 

[dejo]

Do you have a UINavigationController as your container-controller / rootViewController? That code from the document is just an example, for if you do.

 

[Danneman101]

No, you're right, I have a UITabBarController in the top hierarchy:



However, trying to set that as the rootviewcontroller as such (using FirstViewController since SecondViewController is actually a subview of another view)...

    UITabBarController *rootNavigationController = (UITabBarController *)self.window.rootViewController;
    FirstViewController *FirstVC = (FirstViewController *)[rootNavigationController topViewController];  //ERROR

...resulted in a build-error "Receiver typ 'UITabBarController' for instance message does not declare a method with selector 'topViewController'".

So I tried replacing "topViewController" with "tabBarController", and this did not cause any build-errors. However, when trying to access the methods in FirstViewController, they were not executed.

    UITabBarController *rootNavigationController = (UITabBarController *)self.window.rootViewController;
    FirstViewController *FirstVC = (FirstViewController *)[rootNavigationController tabBarController];
    [FirstVC OpenEventTab];   // DOES NOT GET CALLED

Does this mean there is simply no way for the AppDelegate in a TabBar-based app using Storyboard to access any of its other views?

 

[dejo]

Does this mean there is simply no way for the AppDelegate in a TabBar-based app using Storyboard to access any of its other views?

There is. But you simply have to stop throwing seemingly random solutions at the issue and step back and think about what you're trying to achieve and what options/properties/etc. are available for you to use.

Does UITabBarController have a topViewController property? No, it doesn't. So, it doesn't make sense to try and reference a non-existent property. Think about how UITabBarController is a container for controllers and how those viewControllers (one for each tab) are stored in its object. Then look at the class reference and see if it has a property that would allow you access to that. And then think about how you might get a reference to your FirstViewController from there.

So, in summary: stop flailing, step back, use the documentation.

 

[Danneman101]

You're right, I'm letting my frustration get the best of me.

I've taken a closer look at the UITabBarController docs, and realized that it is a ViewController container, containing viewControllers in an array-property that is aptly called "viewControllers" which I can get at using the objectAtIndex-method.

So, I first access the top dog of the app (ie. the tabbarcontroller) as such:

    UITabBarController *tabBarController = (UITabBarController *)self.window.rootViewController;            // GET: TabBarCtrl ->

Then I can use this object to find the viewControllers it contains as such:

    FirstViewController *FirstVC = [[tabBarController viewControllers] objectAtIndex:0];                    // GET: FirstVC

To get a subview of a navigationController (which is the case with SecondViewController, see the image with the storyboard), I similarly use:

	UINavigationController *navigationController = [[tabBarController viewControllers] objectAtIndex:1];    // GET: NavController containing SecondViewController
	SecondViewController *SecondVC = [[navigationController viewControllers] objectAtIndex:0];              // GET: SecondVC

Finally it works

Thanks for having the patience to set me straight, dejo

 

[dejo]

Thanks for having the patience to set me straight, dejo

You're welcome.

A word of warning though: at first glance, would you think FirstVC and SecondVC are variable names or class names? I'd suggest you follow the standard naming conventions.

 

[Danneman101]

True. I usually never use capital letters to begin an instance name. For instance, FirstVC was called firstVC earlier - don't know why I changed it. Sloppy.