stringByEvaluatingJavaScriptFromString in didReceiveRemoteNotification but after webView is loaded - ios

Question

I am facing a problem in iOS push notification in a Cordova hybrid app, need guidance/help in identifying whether I am doing it the right way?
Here is the flow ->
User recieved push notification while app is in background -> Tap on the notification from the notification center -> App is opened (invoked) -> Get the custom payload values -> perform a JS Callback using stringByEvaluatingJavaScriptFromString -> The JS function will do the necessary actions the app has to do.
Here is my code where I am doing it
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {
[[Pushbots sharedInstance] receivedPush:userInfo]; //Using Pushbots notification platform
NSString* Value1 = [userInfo objectForKey:#"val1"];
NSString* Value2 = [userInfo objectForKey:#"val2"];
NSString * jsCallBack = [NSString stringWithFormat:#"testfromdelegate('%#','%#')", Value1, Value2];
NSLog(#"%#", jsCallBack);
[self.viewController.webView stringByEvaluatingJavaScriptFromString:jsCallBack];
}
Everything works till my NSLog(#"%#", jsCallBack);, and it fails at the jsCallBack. I understood that by the time my jsCallBack is being called, the webView is not yet ready, as the app is invoked from background.
What do I do to make this work? How to check whether my webView is ready, and then perform my jsCallBack?
How do I do this when the app is not running at all? For e.g., a user received a Whatsapp message and the app is not in background/foreground. But when the user taps on the message from the notification center, the whatsapp app opens with the user chat screen.
PS: All this code perfectly works when the app is in foreground. That means, the webView is already there and so jsCallBack has no problem.

Answer 1

If the app is in open or in background, then you can execute the javascript directly:
//This will be called if the app was open, in the foreground (active) or in the background and you reopen it from a push message
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo {
[[Pushbots sharedInstance] receivedPush:userInfo]; //Using Pushbots notification platform
NSString* Value1 = [userInfo objectForKey:#"val1"];
NSString* Value2 = [userInfo objectForKey:#"val2"];
NSString * jsCallBack = [NSString stringWithFormat:#"testfromdelegate('%#','%#')", Value1, Value2];
NSLog(#"%#", jsCallBack);
// If the app is in the foreground just execute the javascript
if ( application.applicationState == UIApplicationStateActive ) {
[self.viewController.webView stringByEvaluatingJavaScriptFromString: jsCallBack];
} else {
// If the app was in background, then force to execute the js code on the main thread
[self.viewController.webView performSelectorOnMainThread:#selector(stringByEvaluatingJavaScriptFromString:) withObject:jsCallBack waitUntilDone:NO]
}
}
If the app was completelly closed, then you can add an observer that will listen for the CDVPageDidLoadNotification (cordova finish loading), so you store the userInfo in a new variable myUserInfo and wait until the page is loaded to use it:
- (BOOL)application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions
{
//Don't remove the existing code, just paste this before the return YES
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(cordovaDidLoad) name:CDVPageDidLoadNotification object:self.viewController.webView];
//This will be called if the app was closed completelly and you open it from a push
if (launchOptions) { //launchOptions is not nil
NSDictionary *userInfo = [launchOptions valueForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
self.myUserInfo = userInfo;
}
return YES;
}
Then, when cordova is loaded this method will be called:
- (void)cordovaDidLoad {
//Check that myUserInfo isn't null, that will mean that the apps was completelly closed and it was opened from the push notification
if (self.myUserInfo) {
NSString* Value1 = [self.myUserInfo objectForKey:#"val1"];
NSString* Value2 = [self.myUserInfo objectForKey:#"val2"];
NSString * jsCallBack = [NSString stringWithFormat:#"testfromdelegate('%#','%#')", Value1, Value2];
NSLog(#"%#", jsCallBack);
[self.viewController.webView stringByEvaluatingJavaScriptFromString: jsCallBack];
}
}