Within my iPhone application I periodically make calls to a webservice, providing the endpoint with a list of numeric IDs. The webservice then returns information relating to the IDs it receives.
This is all well and good. However, I would like to be able to provide functionality whereby the user will receive a local/push notification when these changes occur, regardless of whether the application is open or not.
I'm just looking for guidance on my options in this scenario. As I see it, there are two main approaches: calculate any data changes on my webserver and send a push notification to all devices, or query the webservice from the device itself.
The second option seems ideal, as not all devices will need each push notification, but I'm unsure as to whether this is possible with the current state of iOS' multitasking APIs. Any advice would be appreciated.
Bad news: it's not possible. Apps can only run in the background for a short period of time after the user has exited unless it fits into a small number of categories (GPS, VoIP, etc).
Web services, unfortunately, do not count. So this would have to be performed on the server side and with push notifications.
Related
My requirement is, I need to call a Web-Service and the count of the data should come on the local notification content on daily at 8 AM
example : you have 10 new notification, the 10 is the count of the data in an array.
Some one please help me to do this.
Thanks in advance.
you cant schedule something like this offline but you have 2 options that differ
with thr app background refresh API you may come close. If you opt in to that api, ios will wakeup your app when it has spare cycles and will give you cpu time to run some code and allow you to do this.
the background refresh api was meant for 'periodic' updates like this IMO. What you cannot do with it though, is schedule any EXACT times/dates/intervals you want to be woken. You can recommend times to ios but it may or may not stick to the plan (this depends on device use .... battery .... time of day...... etc)
another option are a backend that sends 'silent' push notifications at your required time. IOS would wake your app for those notifications and as they are silent, the user wont see it.
you can have a backend send you non silent pushes. Your app will be launched on tapping the notification and you can do whatever you like
==> option 1 works offline, option 2 and 3 require connectivity and even worse a decdicated backend to support it. IMHO option 1 is often very good and underrated.
I have a service that allows user to enter the type of events they like, and whenever a new event that fits those criteria is available in my database, I want them to get a notification.
I have been looking around at the best way to handle it and I have found two possible solutions, but I'm not very clear with which one I should use and how.
First, a solution that looked great was the didReceiveRemoteNotification method and the usage of remote silent notifications to tell the app that new content was available. But my questions remains: how can I send this remote notification to the user if I don't know which criteria he has. I mean, how can I send this notification using PHP? I'm a bit lost here.
So I found another possible solution that does look a lot like a hack (iPhone - Backgrounding to poll for events), to be able to make your app execute a method every XX minutes while it is in background. This would be way more battery consuming and I'm not even sure it would be accepted by Apple, but at least it is clear as to how it works: the app downloads data from a link with the parameters that fit the special criteria, and if there is new data, it sends a notification.
How could I combine both these methods?
EDIT
I think the main issue on my side is that I don't understand how I could check a certain PHP file whenever new data is added into mysql and make sure that it fits the criteria of the user and then send the notification. That is the part that I don't understand in the backend PHP usage.
Your flow should be like this -
Mobile -> BackendServer(PHP) -> APNS server -> Notifications->Back on device.
User will submit her/his criteria to server then server will process on that and send request to APNS server.
The APNS server will send remote notification on her/his device based on criteria requested.
I'm trying to look for a way as to how I can notify a user of new updates based off of a .Net API that I created. Much like that notification you get on facebook, I just need to alert the user that something has been updated. So I'm thinking I need a function that runs in the background while my user uses the app combined with a NSTimer.
Based on my research (and on this question https://stackoverflow.com/a/14835300/639713) apparently you can only achieve such a thing for VOIP and location services. And that using push notification is the only way. Is it really the only option that I can use for such a need? Or are there any other ways?
Thank you for your time.
You have two options:
While your app is open, poll the server every so often to see if there are any updates to report.
This will work only as long as the user has your app open, and as you note, your app will only be allowed to stay open for a long time if it happens to be a VOIP or navigation app.
Use push notifications to push updates to the user’s device.
The disadvantage here is that you will need to write some server-side code to talk to Apple’s push notification servers (as described in this tutorial). This may or may not be a big deal in your particular situation, but it’s the only way to get data to the user when your app isn’t open.
It's generally a common question.
I wonder how do mail apps implement functionality of email-receiving?
I need to implement a simple sync between two devices(for example) using my web service.
Imagine a to do list app.
Is it possible to implement such a functionality: device1 makes an entry,then sends a message to webservice, webservice informs device2 that changes took place and device2 adjusts its data and displays that entry?
On iOS what you want could easily be implement with push notifications.
As soon as the server detects changes that device2 needs to be aware of the server will send a push notification to that device.
After the user views the notification the app should update it self, it would also be a good idea to let the app update it self when coming to the foreground.
The reason for doing it with Push Notification and not polling is that if your app is in the background you can only continue to run a process for 10 min max. You might get around this by adding the background mode to your app, like VOIP, Audio or location. But if you app does not fall in those categories apple might reject your app.
With Push notification the device will receive the notification even if your app isn't running or in background.
Basically there are 2 ways:
polling, each device asks the webserver for changes every N minutes: new todo, delete a todo, change a todo, ... and then each device will adjust. The frequency of the poll depends of the level of real time you are looking for. It can be 1 call every second or every 12 hours or much more.
implement a kind of BOSH protocol: the device opens a connection to the server. The server keeps it open until there something new to send to the device or the connection times out. In that case, the device reopens it.
Option 1 is better for your todo app because you don't need real-time accuracy. The option 2 is better for a chat application where you don't want to wait for the message.
I have an application which takes characters from a web page and compares them to a UILabel in the application. What I want to do is enable the app to continue to do this even when the user has placed the app in a suspended state. All I have found online and in the documentation is the way to schedule a UILocalNotification while still in the active state. In the documentation, it states that you can declare certain permissions in the info.plist. I looked at the categories, but my application cannot really fit any of those.
Is there a way for me to continue comparing the two strings and scheduling a notification while in the background?
Thanks.
iOS doesn't really support multi-tasking in the manner you require. (i.e.: You can't simply carry on processing data in the background unless you're a very specific kind of app such as a VOIP service, etc.) otherwise you're likely to end up being terminated.
However, one possible solution would be to carry our this monitoring on a separate system (e.g.: a web server that your app interacts with) rather than within the app itself. You'd therefore:
Communicate the required string/web page to your web service
Carry out the processing on the web server.
Send a push notification to your app if the string was found on the page in question.