I am stuck to a point, I am managing my app offline also.. first time i get all data (images) from a webservices and store its path into sqlite, now I take an int value 0 or 1 and store its state into NSUserDefaults now I am facing problem in updating those images, like if images are changed how should I notify into my app, I searched it on Google and only solution is to send push notification to app when record is updated. What if user do not allow push notification?
Is there any other solution to manage app offline and update only when record is changed from online database?
You can sync your Data with server Periodically , like call a webservice which check if images have been changed then fetch the new images and if images are not changed then continue with old data.You can add a Boolean Value on server end which can tell you if data on server is updated or not or you can check this with Time stamp like when data is updated last time then compare your local time with Server time at which data has been updated . Good Luck !!
There are ways to handle such kind of situation:
Use push notifications which is the best solution for such situation.
Query the server periodically by giving the ability to the user to set the time interval from app settings.
Query the server whenever the app came from background to foreground.
An idea is to use BackgroundFetch to update the app content while it is not running. I am using similar fetch for one of my apps where I update the content before the user opens the app. I am fetching a small list of items that is indicating which one is up to date and which is not. Then, at runtime I present an option to the user to manually update these items, but of course you can also download all that while in backgroundfetch. My app is without network reach most of the time, and backgroundFetch will update the items list first thing when there is some internet connection.
There are two important methods here that you need to register, setMinimumBackgroundFetchInterval: and application:performFetchWithCompletionHandler: . You can read more about them in Apples guides for background modes.
You can also check out this good tutorial about this fetching capability: http://www.appcoda.com/ios7-background-fetch-programming/
There is way which has being most popular as most of peoples are preferring
At server side build mechanism, which can send lists of images updated after particular date/time.
To keep track of last sync date/time at locally.
Pinged on server with last date/time in case of first time pass any past date and check for update, if there is then download updated images, Otherwise.
Now you have to decide this process when would be query to server
1) At every first time application will be load. (At didFinishLaunchingWithOptions).
2) Query the server periodically by giving the ability to the user to set the time interval from app settings or else where would be preferable.
3) Query the server whenever the app came from background to foreground.
Related
I am developing an iOS app which needs to receive regular data from the server at specific period of time (every 5 seconds).
Apple gives developers some choices for background working.
I convinced that Background Fetch is the proper method for my problem.
But when I tested it I got confused.
Background Fetch has many issues with my requirements:
It does not fetch data at period you defined when declared it:
application.setMinimumBackgroundFetchInterval(UIApplicationBackgroundFetchIntervalMinimum)
I tried this and this:
application.setMinimumBackgroundFetchInterval(5). But no guarantee
that your app will fetch data at this interval.
When the screen is off, your app will not make any fetch until the
phone is unlocked again.
I wonder if there is a way that let my app receives real time data (or at least every 5 seconds).
Note: I read about remote notifications and I do not guarantee that I can execute it now, So I am searching for other solutions.
Thanks
There is no solution to this problem until writing this answer.
If I need a real time notification then I must use Push Notification.
There is no way to check for server data every period of time from the app only, I can send a Remote Notification when new data available on server to wake up the app and let it connect to the server.
I am looking for a good way how to make my app "upToDate". These are my requirements:
I have an RESTful Webservice, with tasks for different users. Every user has an iOS App, which should get automatically updated when the Server/Service assigned a task to that User.
So first ill created a manuall "Sync" Button, which checks for new Tasks. Fetches the data with Alamofire, and updated the UI.
But, my goal is automatically sync if there are new tasks.
So, ill guess there are 2 different ways to solve that:
1. Make a Background Fetch (with a NStimer?) every xx Minutes and check if there are new tasks.
After checking that tutorial here:
http://www.raywenderlich.com/92428/background-modes-ios-swift-tutorial i am not sure if a background fetch is a good way to solve that. In that case the App uses an scheduler, to check once for new updates, and not every xx minutes.
So in my case i would create an NStimer in the AppDelegate (maybe in applicationDidEnterBackground) and check every xx minutes for new data (but when there are 3 days not any new task, that would be unnecessary battery consumption, or?)
2. Using Push Notifications.
My other idea is to use Push Notifications, so when there is a new task, ill send a Push Notification an manually start the sync. In my opinion that would use less battery, because he will only start the sync when there is a new task available.
Generaly Questions about using Background Services
So ok, if the user finished the task, some data should be automatically uploaded to the server. Normally not a problem, with the manual sync ill check if there is something to upload. But, what if, when there is no internet connection (ill check if before uploading) - and the user do not press on "manual sync".
So i would prefer to check in my "Background Service" if ill got an Internet connection, and if yes - start uploading some data.
Ill know this is not a specific question, but ill think there are lots of users who have the same requirements and it would be great if someone can help me out whats the best way to solve that in the best and practical way.
Thanks in advance!
Background updates sound wonderful until you realise that Apple throttles them heavily: you can ask to be updated as frequently as possible, but iOS decides what that value actually means based on how often users open your app and when they do so. Apple considers background updates the kind of thing that should happen just before a user opens your app so the latest content is right there, rather than something that runs proactively in the background.
Your push notification solution is a better one, particularly if you use CloudKit to subscribe to record change events using CKSubscription and CKNotificationInfo. If you do this you'll automatically get push messages in your app, so you can get what you want with very little work. You can read my tutorial for more information on subscribing to CloudKit to get push messages.
I'm building my first application.
I'm making app where I'm doing some fetching from rss feed of web site and loading it to a TableView. What I want is next:
-to inform a user when new feed arrive, when my app is closed (user can set the time interval of update frequency in app settings page) - with Local Notification
I'm using NSURLSession for downloading data, storing it with Core Data, and want the Deployment Target to be iOS 7.1.
Just want to know is it possible and steps that I need to do to implement it correctly.
What you want is called Background Fetch. Background fetch can fetch data from your servers even when the app is not running.
Local notifications would be of no help here. Even when a local notification has been fired, user will have to click on it to fetch data.
Look it up. There is a pretty decent tutorial here.
I need a piece of code for Xcode (obj-c) that runs every day at 00:00.
The reason for this is because my server updates data each new day and I would like my app to synchronize with the update.
I was thinking about doing a timer that runs every minute and checks the time (from internet, not the phones time), but it seems like there could be an more efficient way.
Help or pointers really appreciated!
Thanks
Use the calendar app on your mac. Set up a recurring event every day at 0:00. At the point where you pick the type of alert, you can select an option to open a file (as opposed to a pop-up, etc.). Pick your app as the file to be opened.
When the app becomes active, register a local notification (UILocalNotification) to trigger at midnight.
Then, you can perform the updates at the app delegate's -application:didReceiveLocalNotification:
You can then cancel the notification when the application goes to background by calling the UIApplication's method -cancelLocalNotification:
I don't think it's even required to use notification here. Notification is usually on best effort basis and doesn't guarantee the delivery. This can be done in few simple steps.
Save the lastUpdated time in your iOS app. Probably in NSUserDefaults or if you're using local database you can store it there as well.
Everytime user launches the application check how much time has elapsed since last update.
If it's more than 24 hours then make an API call to your server and check if there's any new updates available (which you can determine probably from server timestamp). Get the latest data (possibly only the delta difference in stead of everything).
Update the lastUpdated time in your iOS app.
i'm writing an app that manage a sqlite database, and i have write a web server, i want the user register in my web server with username and password, i already know how make a request from ios app to server and receive the response, but i want enable also the synchronization of the sqlite database to other device, i now that with core data i can use iCloud synchronization, but for now i prefer use sqlite, and find a way to synchronize it, for example i want create this:
make a change in the sqlite in the iPhone app;
the app send this change to the server for that user;
then the server have to send this update to other device connected at that user;
and now i can't go over, how the server can send this change to the other device? the device has to be always listen to the server? or there is a way to send this update directly to some device and handle it? like an apple push notification?
EDIT: if it's possible use an apple push notification to do this, i doesn't want alert with text sound and badge the user, but send a "silent notification" it's possible?
As a high-level there are a few different ways to approach this, all of which have pros and cons. Two name two examples you can do a polling method, active push or a hybrid approach.
Polling: at some pre-determined interval the app tries to "phone home" and send the delta db changes up to the server. Here you know that your server will be expecting X number of responses in any given interval so you can appropriately gauge your load.
Active Push: The user decides when they want those changes to be transmitted to the server by hitting a "Sync" button. This allows the user to only push data back up to the server when they know there's a change but an over zealous user may make a change, upload, make a change, upload, etc instead of queueing up a bunch of changes and sending them all at once. This may create frequently unneeded server calls.
Hybrid: You setup a polling schedule within the app AND give the user the ability to Sync at-will in the event there is a critical change that needs to be made ASAP.
Regarding the listener side of the equation you face a similar challenge conceptually. If the original user makes 20 changes and presses Sync 20 times do you bombard the second user's device 20 times as well or do you queue those changes up and send them down every 5 minutes (as an example)? Unless you have both devices paired to each other or are connected to the same network AND visible to each other via your app you're going to need to leverage that back-end server. Push notifications can be very useful in this manner but there is extra development and setup overhead to take into account to properly implement them.
To boil this all down I would recommend laying out what YOU want your syncing model to look like before you start marching down a path.