I am creating a local UILocalNotification and displaying it to the user as a banner. Is it possible to set it up so that when the user taps it and returns to the app, the app will receive some kind of data on the specific kind of notification it was? I want to open a specific view controller in the app. I think the best way would be to essentially send a URL to the app, or is there a way to get access to the UILocalNotification so that I can test which kind is was and do the right action?
To get data from the local NSUserNotification that is passed to an iOS app, all that you need to do is implement the following method: - (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification.
The problem is, this is called both when a local notification is posted when the app is in the background (i.e. when the user taps on the notification and then returns to the app), and also if the app is in the foreground at the time when the local notification fires (it is on a timer, after all). So how should one figure out if the notification was fired when the app was in the background or foreground? It's pretty simple. Here's my code:
- (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotification *)notification {
UIApplicationState state = [application applicationState];
if (state == UIApplicationStateInactive) {
// Application was in the background when notification was delivered.
} else {
// App was running in the foreground. Perhaps
// show a UIAlertView to ask them what they want to do?
}
}
At this point you can handle the notification based on notification.userInfo, which holds a NSDictionary.
ust implement the NSUserNotificationCenterDelegate and define this method:
- (void)userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification
Example:
This is what I did in a "notifier" application.
- (void) userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification
{
NSRunAlertPanel([notification title], [notification informativeText], #"Ok", nil, nil);
}
- (void) userNotificationCenter:(NSUserNotificationCenter *)center didDeliverNotification:(NSUserNotification *)notification
{
notifications=nil;
[tableView reloadData];
[center removeDeliveredNotification: notification];
}
When the notification is activated (click by the user) I just inform the user with a panel (I could use a hud window).In this case I immediately remove the delivered notification, but this is not what happens usually.The notification could stay there some time and be removed after 1/2 hours (it depends on the application that you are developing).
1 - Define some class in your project to implement NSUserNoficationCenterDelegate protocol (documented here)
#interface someObject : NSObject <NSUserNotificationCenterDelegate>
{
- (void)userNotificationCenter:(NSUserNotificationCenter *)center didActivateNotification:(NSUserNotification *)notification;
}
2 - Set an instance of the object defined #1 as the delegate of default notification center.
[[NSUserNotificationCenter defaultNotificationCenter] setDelegate: someObject];
Now you will get called on didActivateNotification any time the user taps/clicks on the notification. You will have the original notification you created. So any information that you need should be available to you.
If you want/need special information (other than notification title, message, etc) you will probably need to set additional application specific information in your notification before you schedule it to be sent. For example:
NSUserNotification* notification = [[NSUserNotification alloc] init];
NSDictionary* specialInformation = [NSDictionary dictionaryWithObjectsAndKeys: #"specialValue", #"specialKey", nil];
[notification setUserInfo:specialInformation];
I have used Push notification in my application, when the notification arrives i will get some values in the payload and i need to update the values in my application. I have amount label in all the views, so i need to update the amount after receiving the notification. But the problem is, the value doesn't update instantly, when i navigate to any view after that it will update. I want to update the value instantly, so how can i do that?
-(void) application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo{
NSString *getAmt =[[userInfo valueForKey:#"aps"] valueForKey:#"Amount"];
float totalAmt = [getAmt floatValue] + [amt floatValue];
NSString *finalAmount = [NSString stringWithFormat:#"%.02f",totalAmt];
[[NSUserDefaults standardUserDefaults] setObject:finalAmount forKey:#"amount"];
[self.viewController.view setNeedsDisplay];
}
I am using the Nsuserdefault value for displaying the amount in the amount label. Now the values are changed, when i am navigates to any view after that it will update. But i want to update the value instantly in my application, after getting the notification. So please help me out.
Thanks!
use NSNotication and add a notification against a method of class where method is implemented, when you receive push notification, post that notification and in method update values
Well, you can use NSNotificationCenter for this purpose..
Register you desired UIViewController in NSNotificationCenter for #"NotificaitonRecivied"
like this:
[[NSNotificationCenter defaultCenter] addObserver:self
selector: #selector(updateAmount:)
name: #"NotificaitonRecivied"
object: nil];
now whenever you receive any updated amount, simply broadcast a notification like this:
[[NSNotificationCenter defaultCenter] postNotificationName:#"NotificaitonRecivied" object:nil];
updateAmount: amount will be a method to read your amount from NSUserDefaults to set it on any View
Hello i am new to objective - c
I'm having a problem with the UIWebView and MPMoviePlayerController: My UIWebView has a movie inside the html (it's a local html file), I'm using html5 and a video tag for the video.
I want a notification when video starts or stops in UIWebView....
I have tried using MPMoviePlayerPlaybackDidFinishNotification, but it doesnt fire ...
I have also tried to make the my main UIViewController's view a view of my own, and intercept -didAddSubview: and -willRemoveSubview:. but with no sucess...
Does any body know how to get notification from uiwebview??
You can observe #"MPAVControllerPlaybackStateChangedNotification" (use nil for the object). This notification isn't documented so I don't know if the App Store will approve your app.
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playbackStateDidChange:)
name:#"MPAVControllerPlaybackStateChangedNotification"
object:nil];
The notification has the key MPAVControllerNewStateParameter in its userInfo. The value seems to be 0 before playback starts, 1 when it is paused, 2 when it is playing, and 3 (momentarily) when you are dragging the playback slider.
- (void)playbackStateDidChange:(NSNotification *)note
{
NSLog(#"note.name=%# state=%d", note.name, [[note.userInfo objectForKey:#"MPAVControllerNewStateParameter"] intValue]);
}
I searched alot about this..Here is the solution that I have found for getting the playback end notification call. Tested code on iOS6.0 and above. All thanks to #Morten.
In viewDidLoad add observer
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(playbackDidEnd:)
name:#"MPAVControllerItemPlaybackDidEndNotification"//#"MPAVControllerPlaybackStateChangedNotification"
object:nil];
Then simply add following javascript code webViewDidFinishLoad delegate as below
- (void)webViewDidFinishLoad:(UIWebView *)webView {
//http://stackoverflow.com/a/12504918/860488
[videoView stringByEvaluatingJavaScriptFromString:#"\
var intervalId = setInterval(function() { \
var vph5 = document.getElementById(\"video-player\");\
if (vph5) {\
vph5.playVideo();\
clearInterval(intervalId);\
} \
}, 100);"];
}
- (void)playbackDidEnd:(NSNotification *)note
{
//do your stuff here
[videoView removeFromSuperview];
videoView.delegate = nil;
videoView = nil;
}
You will get playbackDid End call in the above selected and can do whatever is your requirement.
Happy Coding !!
I was wondering what is the best practice for an application flow in iPhone development.
How do you pass messages between ViewControllers?
Do you use singletons? pass it between views or do you have a main controller for the application that manage the flow?
Thanks.
I use NSNotificationCenter, which is fantastic for this kind of work. Think of it as an easy way to broadcast messages.
Each ViewController you want to receive the message informs the default NSNotificationCenter that it wants to listen for your message, and when you send it, the delegate in every attached listener is run. For example,
ViewController.m
NSNotificationCenter *note = [NSNotificationCenter defaultCenter];
[note addObserver:self selector:#selector(eventDidFire:) name:#"ILikeTurtlesEvent" object:nil];
/* ... */
- (void) eventDidFire:(NSNotification *)note {
id obj = [note object];
NSLog(#"First one got %#", obj);
}
ViewControllerB.m
NSNotificationCenter *note = [NSNotificationCenter defaultCenter];
[note addObserver:self selector:#selector(awesomeSauce:) name:#"ILikeTurtlesEvent" object:nil];
[note postNotificationName:#"ILikeTurtlesEvent" object:#"StackOverflow"];
/* ... */
- (void) awesomeSauce:(NSNotification *)note {
id obj = [note object];
NSLog(#"Second one got %#", obj);
}
Would produce (in either order depending on which ViewController registers first):
First one got StackOverflow
Second one got StackOverflow
The NSNotification class is a bit heavyweight, but fits the usage you describe. The way it works is that your various NSViewControllers register with an NSNotificationCenter to receive the events they're interested in
Cocoa Touch handles the routing, including providing a singleton-like "default notification center" for you. See Apple's notification guide with more info.
How can I detect lock/unlock events on the iPhone? Assuming it's only possible for jailbroken devices, can you point me to the correct API?
By lock events, I mean showing or hiding the Lock Screen (which might need a password to unlock, or not).
You can use Darwin notifications, to listen for the events. From my testing on a jailbroken iOS 5.0.1 iPhone 4, I think that one of these events might be what you need:
com.apple.springboard.lockstate
com.apple.springboard.lockcomplete
Note: according to the poster's comments to a similar question I answered here, this should work on a non-jailbroken phone, too.
To use this, register for the event like this (this registers for just the first event above, but you can add an observer for lockcomplete, too):
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
(void*)self, // observer (can be NULL)
lockStateChanged, // callback
CFSTR("com.apple.springboard.lockstate"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
where lockStateChanged is your event callback:
static void lockStateChanged(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo) {
NSLog(#"event received!");
if (observer != NULL) {
MyClass *this = (MyClass*)observer;
}
// you might try inspecting the `userInfo` dictionary, to see
// if it contains any useful info
if (userInfo != nil) {
CFShow(userInfo);
}
}
The lockstate event occurs when the device is locked and unlocked, but the lockcomplete event is only triggered when the device locks. Another way to determine whether the event is for a lock or unlock event is to use notify_get_state(). You'll get a different value for lock vs. unlock, as described here.
Round about answer:
Application will resign active gets called in all sorts of scenarios... and from all my testing, even if your application stays awake while backgrounded, there are no ways to determine that the screen is locked (CPU speed doesn't report, BUS speed remains the same, mach_time denom / numer doesn't change)...
However, it seems Apple does turn off the accelerometer when the device is locked... Enable iPhone accelerometer while screen is locked
(tested iOS4.2 on iPhone 4 has this behavior)
Thus...
In your application delegate:
- (void)applicationWillResignActive:(UIApplication *)application
{
NSLog(#"STATUS - Application will Resign Active");
// Start checking the accelerometer (while we are in the background)
[[UIAccelerometer sharedAccelerometer] setDelegate:self];
[[UIAccelerometer sharedAccelerometer] setUpdateInterval:1]; // Ping every second
_notActiveTimer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:#selector(deviceDidLock) userInfo:nil repeats:NO]; // 2 seconds for wiggle
}
//Deprecated in iOS5
- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration
{
NSLog(#"STATUS - Update from accelerometer");
[_notActiveTimer invalidate];
_notActiveTimer = [NSTimer scheduledTimerWithTimeInterval:2 target:self selector:#selector(deviceDidLock) userInfo:nil repeats:NO];
}
- (void)deviceDidLock
{
NSLog(#"STATUS - Device locked!");
[[UIAccelerometer sharedAccelerometer] setDelegate:nil];
_notActiveTimer = nil;
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
NSLog(#"STATUS - Application did become active");
[[UIAccelerometer sharedAccelerometer] setDelegate:nil];
[_notActiveTimer invalidate];
_notActiveTimer = nil;
}
I know... It's kind of a hack, but it has worked like a charm for me so far. Please update if you see any issues that prevent this from working.
There is a prettier way of telling apart task switching and screen locking-originated applicationWillResignActive: callbacks which doesn't even involve undocumented features such as the accelerometer state.
When the app is moving to the background, the app delegate is first sent an applicationWillResignActive:, then an applicationDidEnterBackground:. When the app is interrupted by pressing the Lock button or by an incoming phone call, the latter method is not called. We can use this information to distinguish between the two scenarios.
Say you want to be called back in the screenLockActivated method if the screen gets locked. Here's the magic:
- (void)applicationWillResignActive:(UIApplication*)aApplication
{
[self performSelector:#selector(screenLockActivated)
withObject:nil
afterDelay:0];
}
- (void)applicationDidEnterBackground:(UIApplication*)aApplication
{
[NSObject cancelPreviousPerformRequestsWithTarget:self];
}
- (void)screenLockActivated
{
NSLog(#"yaay");
}
Explanation:
By default, we assume that every call to applicationWillResignActive: is because of an active->inactive state transition (as when locking the screen) but we generously let the system prove the contrary within a timeout (in this case, a single runloop cycle) by delaying the call to screenLockActivated. In case the screen gets locked, the system finishes the current runloop cycle without touching any other delegate methods. If, however, this is an active->background state transition, it also invokes applicationDidEnterBackground: before the end of the cycle, which allows us to simply cancel the previously scheduled request from there, thus preventing it from being called when it's not supposed to.
Enjoy!
As of the time of writing there are two fairly reliable ways to detect device locking:
Data Protection
By enabling the Data Protection entitlement your app can subscribe to the applicationProtectedDataWillBecomeUnavailable: and applicationProtectedDataDidBecomeAvailable: notifications to determine with high probability when a device that uses passcode/TouchID Authentication is locked/unlocked. To determine if a device uses a passcode/TouchID LAContext can be queried.
Caveats: This method relies on the "protected data becoming unavailable" coinciding with the phone being locked. When the phone is using TouchID and the sleep/lock button is pressed then the phone is locked, protected data becomes unavailable, and a passcode will immediately be required to unlock it again. This means that protected data becoming unavailable essentially indicates that the phone has been locked. This is not necessarily true when someone is using just a passcode since they can set the "requires passcode" time to anywhere from immediately to something like 4 hours. In this case the phone will report being able to handle protected data but locking the phone will not result in protected data becoming unavailable for quite some time.
Lifecycle Timing
If your app is in the foreground there will be a noticeable change in time difference between the two lifecycle events UIApplicationWillResignActiveNotification and UIApplicationDidEnterBackgroundNotification depending on what triggers them.
(This was tested in iOS 10 and may change in future releases)
Pressing the home button results in a significant delay between the two (even when the Reduced Motion setting is enabled):
15:23:42.517 willResignActive
15:23:43.182 didEnterBackground
15:23:43.184 difference: 0.666346
Locking the device while the app is open creates a more trivial (<~0.2s) delay between the two events:
15:22:59.236 willResignActive
15:22:59.267 didEnterBackground
15:22:59.267 difference: 0.031404
in iOS 8, you lock the screen or push the home button, all of those make app push in background, but you don't know which operator result in this. My solution same with Nits007ak,use notify_register_dispatch to get state.
#import <notify.h>
int notify_token
notify_register_dispatch("com.apple.springboard.lockstate",
¬ify_token,
dispatch_get_main_queue(),
^(int token)
{
uint64_t state = UINT64_MAX;
notify_get_state(token, &state);
if(state == 0) {
NSLog(#"unlock device");
} else {
NSLog(#"lock device");
}
}
);
As long as the app is running, in foreground or background. not suspend, you can get this event.
And you can use notify_token as parameter of notify_get_state to get current state anywhere, this is useful when you want know the state and the screen state don't change.
If passcode is set, you can use these event in AppDelegate
-(void)applicationProtectedDataWillBecomeUnavailable:(UIApplication *)application
{
}
- (void)applicationProtectedDataDidBecomeAvailable:(UIApplication *)application
{
}
Just import #import notify.h before using this code. enjoy!!
-(void)registerAppforDetectLockState {
int notify_token;
notify_register_dispatch("com.apple.springboard.lockstate", ¬ify_token,dispatch_get_main_queue(), ^(int token) {
uint64_t state = UINT64_MAX;
notify_get_state(token, &state);
if(state == 0) {
NSLog(#"unlock device");
} else {
NSLog(#"lock device");
}
NSLog(#"com.apple.springboard.lockstate = %llu", state);
UILocalNotification *notification = [[UILocalNotification alloc]init];
notification.repeatInterval = NSDayCalendarUnit;
[notification setAlertBody:#"Hello world!! I come becoz you lock/unlock your device :)"];
notification.alertAction = #"View";
notification.alertAction = #"Yes";
[notification setFireDate:[NSDate dateWithTimeIntervalSinceNow:1]];
notification.soundName = UILocalNotificationDefaultSoundName;
[notification setTimeZone:[NSTimeZone defaultTimeZone]];
[[UIApplication sharedApplication] presentLocalNotificationNow:notification];
});
}
From a lot of trial and error, discovered monitoring the blank screen, lock complete and lock state events gives a consistent lock screen indicator. You'll need to monitor a state transition.
// call back
void displayStatusChanged(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo)
{
// notification comes in order of
// "com.apple.springboard.hasBlankedScreen" notification
// "com.apple.springboard.lockcomplete" notification only if locked
// "com.apple.springboard.lockstate" notification
AppDelegate *appDelegate = CFBridgingRelease(observer);
NSString *eventName = (__bridge NSString*)name;
NSLog(#"Darwin notification NAME = %#",name);
if([eventName isEqualToString:#"com.apple.springboard.hasBlankedScreen"])
{
NSLog(#"SCREEN BLANK");
appDelegate.bDeviceLocked = false; // clear
}
else if([eventName isEqualToString:#"com.apple.springboard.lockcomplete"])
{
NSLog(#"DEVICE LOCK");
appDelegate.bDeviceLocked = true; // set
}
else if([eventName isEqualToString:#"com.apple.springboard.lockstate"])
{
NSLog(#"LOCK STATUS CHANGE");
if(appDelegate.bDeviceLocked) // if a lock, is set
{
NSLog(#"DEVICE IS LOCKED");
}
else
{
NSLog(#"DEVICE IS UNLOCKED");
}
}
}
-(void)registerforDeviceLockNotif
{
// screen and lock notifications
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
CFBridgingRetain(self), // observer
displayStatusChanged, // callback
CFSTR("com.apple.springboard.hasBlankedScreen"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
CFBridgingRetain(self), // observer
displayStatusChanged, // callback
CFSTR("com.apple.springboard.lockcomplete"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), //center
CFBridgingRetain(self), // observer
displayStatusChanged, // callback
CFSTR("com.apple.springboard.lockstate"), // event name
NULL, // object
CFNotificationSuspensionBehaviorDeliverImmediately);
}
To have the screen lock indicators run in the background, you need to implement background processing calling the following upon app launching.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.backgroundTaskIdentifier =
[[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:^{
[[UIApplication sharedApplication] endBackgroundTask:self.backgroundTaskIdentifier];
}];
[self registerforDeviceLockNotif];
}
If your app is running and the user locks the device your app delegate will receive a call to 'application Will Resign Active:'. If your app was running when locked, it will receive a call to 'application Did Become Active:' when the device is unlocked. But you get the same calls to your app if the user gets a phone call and then chooses to ignore it. You can't tell the difference as far as I know.
And if your app wasn't running at any of these times there is no way to be notified since your app isn't running.
The simplest way to get screen lock and unlock events are by adding event observers using NSNotificationCenter in your viewcontroller. I added the following observer in the viewdidload method. This is what i did:
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(applicationEnteredForeground:)
name:UIApplicationWillEnterForegroundNotification
object:nil];
Then I added the following selector to the viewcontroller. This selector will get called when the screen is unlocked.
- (void)applicationEnteredForeground:(NSNotification *)notification {
NSLog(#"Application Entered Foreground");
}
If you want to detect the event when screen gets locked, you can replace UIApplicationWillEnterForegroundNotification with UIApplicationDidEnterBackgroundNotification.