I'm working on giving our users context-specific PUSH notification settings, similar to what Facebook has in their settings menu.
As far as I can tell though, there's no way to actually notify our server of these changes until the user actually launches the app.
Is this correct? Is there any mechanism provided for immediately alerting our servers to a settings change?
That's correct: you can't detect changes made in the settings app until the next time your app launches.
The closest option to what you're describing would be to put the settings in your app somewhere and notify the server from there.
Related
I created a web app and added to my iPhone Home Screen. When I switch to another app and back, iPhone automatically reload my web app. This breaks my app flow.
How do I prevent iPhone from reloading the app?
I have apple-mobile-web-app-capable meta tag enabled to hide Safari toolbar and I don't want to turn it off.
I just found this related question on SO: Stop native web app from reloading itself upon opening on iOS
As it seems it's a limitation of Safari, a proposed solution is to persist your web apps state using Javascript and HTML5 localStorage. When your web app is launched, check for the persisted state and load it if available.
You can read about using localStorage in Safari here: http://developer.apple.com/library/safari/#documentation/iPhone/Conceptual/SafariJSDatabaseGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40007256-CH1-SW1
Hope that helps you. At least it did for me, as I had the same problem as you. :-)
The short answer is that you can't control this. Sometimes iOS will keep a web app active in the background, at other times it will kill it. It's entirely related to how much memory is available on the device.
So, your best approach is to minimise the problems presented by this reload. Make sure your webapp updates the URL when you move from view to view, either by changing location.hash or using history.pushState(). This will allow you to reload whatever view the user was on before they switched apps. There are pagehide and pageshow events that allow you to execute code when the user moves away from your app - take that opportunity to store local state in localStorage and/or IndexedDB, then fetch that data again when the webapp is reopened.
I found a hack, tested on iOS 11.4.1/12.0
Open file uploading window and then switch back to the home screen.
The app still continues to work, in my case audio is playing and localStorage is updating
Proofs:
https://youtu.be/heehLUhGKYY
PS. note how song progress changes when we seek, it proves that app works in the background
Update: as this answer is receiving downvotes, I added this explanation.
Your problem might not be the actual reload, but the fact that Mobile Safari treats your user's cache and cookies differently when your web app is opened through the browser, than when it's 'installed' as a web app to the home screen. Although the solutions proposed here that use localStorage will work, they're a lot of work for client-side logic that can be avoided if your server is already responsible for persisting the session state of your user. The 30-second solution is to simply explicitly set the session cookie to have a longer lifetime.
This allows you to keep the state intact even between device reboots, so even though it doesn't technically stop the web app from being reloaded when launched from the home screen, it is an easy way to restore the state for the user without him/her noticing the reload - which in many cases I suspect is the real problem.
For a more elaborate discussion of this strategy and code examples, take a look at these questions and my answers there:
Maintain PHP Session in web app on iPhone
iPhone "Bookmark to Homescreen" removes cookies and session?
Is there any way I can read settings for iPhone preferences. I wanted to read whether the push notification flag is on or not. Based on this setting, I wanted to take some action in my native application. Please guide.
You can read settings for your application using NSUserDefaults. If you are asking if you can read whether push notifications are on globally, then no, I don't think you can. If your application asks to use them, it will ask the user if they want to turn them back on, but that is all you can do.
How does the process of "asking if user wants to use Location Services" work?
I read here that a dialog at the installation appears, which asks the user if Location Services should be allowed or not. Does it mean that there is nothing to do for the developer, because the user can change this behavior in settings? So there is no "asking dialog" to implement and no storing in system settings? Does the app need a settings menu where this behavior can be changed?
What is if I want such a settings menu in my app?
The only thing the developer has to be aware of is to check in his code if it is allowed or not? See here.
Sounds reasonable isn't it ? Yes, that's it. No dialog to implement yourself, iOS manages that for you.
The user can change the settings in Settings/General/Location Service.
I am fairly new to iphone app development. I am creating an app that has multiple views. Initially it starts with a view for authentication and then load views according to user interaction. When I build and run the app - the first time it shows the "Default.png" screen and then shows the first view where I do my authentication process (typing in userid,password and do a web service) and then after the credentials are verified it takes me to the next view. When I close the app at this state in the simulator and reopen it again, I am seeing the same state in which I closed my app. But here is what I want. When I relaunch the app I should be able to show the "DEfault.png" and screen and then show my initial authentication view. Can you please help me out on this ? Thanks
It sounds like the problem you are trying to solve is that your authenticated session may time out while the app is suspended and you need to log in again.
Although the proposed solution (setting UIApplicationExistsOnSuspend to true) would work I think you should consider a different approach.
Apple recommends that you do everything you can to make it look like the phone supports multitasking. That is why, by default, your app will suspend and resume instead of exit and relaunch. In your case, though, you may need to re-login to resume the session. I offer you a couple of alternate solutions:
Cache the credentials (ie username and password) and silently use them to resume the session when needed. If the back-end supports this.
Detect when the session has become stale and bring in a view to inform the user that the session has expired and ask them to log in again. This would also address the issue if the user keeps the app active past the timeout of the session.
Both of these approaches should improve perceived app performance and integrate better into the Apple usability guidelines.
That's because iOS 4 apps are supposed to support multitasking. You can change the app so it doesn't: In Info.plist, set UIApplicationExitsOnSuspend to true (i.e. <key> UIApplicationExitsOnSuspend</key><true/>) — make sure it's a boolean and not a string. Note that this will probably make startup slower, since the app has to be launched again.
The other way is to handle applicationDidEnterBackground: in your app delegate and do two things:
Reset your view hierarchy (you can do this on next launch, but doing it earlier might help to free more memory)
Show "Default.png" in a full-screen view — iOS takes a screenshot of your app after it's hidden which it uses to animate the app back in.
I currently have an application that requires the user to maintain a VPN tunnel. On load I check if the VPN tunnel is available.
I am wondering if there is any way for me to display an UIAlertView which on clicking "OK" takes the user to the iPhone main settings screen, so they can turn on VPN.
I know how to store app specific settings and that seem to be the most common articles out there, but is there any way to get your app to redirect the user to the main iPhone settings page?
As said, there's no way to do this currently. You'll have to create your own settings screen inside your app.
See a similar thread here:
How do I open the Settings application from my application?
iPhone has it's own NSURL protocols for apps, such as youtube:, mail:, etc. Judging by the "Airplane Mode" alert, there is clearly one for the Settings app. I imagine it is open, but don't know what the syntax would be off the top of my head. Check the docs about the protocols.