I'm building a reminders app that sends local notifications that repeat based on a user's custom settings. For example, I may send a notification every other day at 8pm. Every time I send one of these notifications, I'd like to replace any previous notification that might be displayed in the user's notification center already.
The new UserNotifications framework in iOS gets me close to being able to do this. As far as I can tell, notifications can be replaced in two ways:
Use a UNCalendarNotificationTrigger with repeats: true. Repeated triggers replace past ones.
Create a new UNNotificationRequest with the same identifier. Whenever a request is sent with the same identifier, it replaces all other instances.
Neither of these solutions quite work for me:
I can't use use repeating notifications because UNCalendarNotificationTrigger uses DateComponents for a repeating schedule which just isn't granular enough. My example above of "every other day at 8pm" can't be described with just DateComponents.
Because I need to schedule several notifications all at once, I must specify unique identifiers, and as such, they don't replace each other when displayed.
I was hoping service extensions would save me here. If I could execute code when I receive a notification, I could programmatically remove old notifications when new ones are triggered. Unfortunately, it appears as if service extensions only work for remote notifications. Even if I could use remote notifications (which is a whole can of worms by itself), this solution kind of bends the rules on what is allowed for service extensions.
Does anyone have any ideas on how to solve this, or am I destined to spam my users' notification centers?
Related
As I see in many apps when setting user notifications as reminders, it works fine but after a while when the user starts to ignore opening the notification or the app it won't send any more notifications.
Is there a way to disable this behavior and continue sending the notifications even if they don't open the app?
What you are describing sounds like local notifications. These are scheduled in code to go off at a specific time. As far as I know there is no such thing as a recurring local notification. They are "simulated" by creating many single local notifications to begin with.
Edit
As PaulW pointed out. Recurring notifications are possible but are rarely used due to their limitations.
When the app is opened it runs some code to create some more local notifications.
If the app is not opened then the code never runs to create the additional notifications.
So, in this example, it is not iOS stopping the recurring notifications because you haven't opened the app. The notifications stop recurring because you don't open the app and give it the opportunity to create more of them.
So, to answer your question. No. The only way to delay this as long as possible is to create notifications that cover a long time into the future. But then I believe there is a limit to the number of scheduled notifications. (A quick google comes up with a limit of 64 scheduled notifications per app).
Edit you could also use repeating notifications but they are limited to repeat every one unit of time. Once a day, once and hour, once a minute, etc... so you can't do it every two hours.
Alternatively you could use a backend to send remote notifications. These could theoretically recur infinitely because the app is not required to create them. Of course, this assumes you have the infrastructure setup to develop this.
I have an iOS app integrated with Parse.com in which I want to schedule push notifications for certain dates/times. I am storing a push notification time on PFInstallation objects for users who have an upcoming event. I have a scheduled job running on Parse CloudCode that queries for push notification times that need to be sent within the next minute. Is this a good way to architect this? If so, how can I send this push? Parse.Push takes a query for it's where field, but queries only return up to 1000 results which doesn't scale at all for a free app. Thus, I'm trying to use Parse.query.each() which has an unlimited number of results. However, now I'm unsure how to send a push to each installation this way? Do I need to create another query within my each() statement? That seems redundant and inefficient.
(Note that the push notification is a silent notification with the content-available flag set so local notifications are not an option. Also the notifications can be cancelled by the user so scheduling the notification with the CloudCode push schedule API is not an option since those pushes can't be cancelled.)
You say, you store push notifications time on the respective PFInstallation object to circumvent the lack of support for canceling a push notification through Parse, great. We'll call that column ScheduledPushDate; That's the easy part; +1. The part you want to accomplish is actually scheduling a push notification using the given date. Great. Another easy part; +1. The hard part is doing it the way you want; -2. Parse.Push is not only limited by the where field. A lot of variables come into play when sending a push, for example, Parse doesn't even consider any objects that don't have a valid deviceToken so you can omit those objects immediately. The problem your running into is not the push itself, its not how to query for validation, its simply comes down to canceling it. Sure you can always change the date in ScheduledPushDate to be something in the year 2025 or simply negating it altogether, but that doesn't matter because you've already given the notification a scheduled date with the payload. Keeping it simple, and according to your target (you tagged iOS, so this is an answer specifically to client-side resources since you don't want to use local notifications or cloud code) you won't be able to cancel it, because within the guidelines given, you can only construct a push notification so many ways with Parse (client-side, cloud code, dashboard), and as of right now, only one of those options allows a successful means to cancel the process, and it's through the dashboard/console.
Lets say you do it the way you are thinking about:
Execute scheduled job to search for push times that need be fired within the coming minute. What is a "coming minute". Lets say a users time is 11:35.46 (11am35m46sec) and they want to cancel the scheduled notification and cancelled it at that moment, but your job fired at 11:35.00? Realistically, how often will that happen, not many, but it will happen and can happen. You should always code for every circumstance a user will encounter, not just the ones you want to prevent.
Additionally, you would be exhausting almost all of your API request limits if you do have a scaleable app as mentioned.
Lastly, to answer your question, no you don't have to do an innerQuery or additional query within the query.each function, as it's job is to iterate over each result of a query
I have 8 medicine local notifications which differ from day to day.
They work fine for one day but I want to fire them everyday. I used BackgroundFetch to reschedule the local notifications every time fetch is executed. But my problem here is that background fetch depends on how often the user uses the app. What if the user doesn't open the app more often Also I didn't want to implement silent notifications because it will not wake up the app if the user does not have internet connection. what approach should I use instead of background fetch?
EDIT:
I also thought about location updates in background because my notification times are taken from location of user and calculated accordingly. But will this consume a lot of battery?
Since I've got the same issue in an
app that probably does the same stuff as yours, I'd like to share my solution.
It comes with one compromise works only from >=iOS8.
By using an interactive notifications you can reschedule your notifications in background, of course the user need to interact with the notification, but I think that if you different actions instead of open the app or cancel the notification is possible to have more interested user.
It's all about creating a configuration with actions.
Here you can find a tutorial.
My calendar app is not connected to Event Kit which allows me to create custom repeating intervals like "every 3 days, 29 times" etc.
Now i would like to add Notifications to my Events ... but my custom repeating events are limiting me in every possible way.
I think I have checked every possible solution:
UILocalNotification
UILocalNotification is limited to 64 events and NSCalendarUnit's in-built Unit Time Intervals aren't very flexible.
1 event repeated every 2 days will fill this up very quickly
Should i reschedule 64 Notifications on every app start and beg the user to start the app regularly? Not running the app for a while will not reschedule notifications.
Event Kit (Calendars & Reminders)
I could create a calendar or Reminder list, generate single events from the custom repeating events and add notifications here. But the user can edit this, which will cause confusion.
I can't synch this back to my app.
Should i create a calendar or reminder list for Alerts and hope that the user will not touch this?
Apple Push Notification Service
Everywhere i can read: They are not reliable! There is no guarantee that push notifications will actually be delivered, even if the APNS server accepted them.
I think push notifications are not made for notifying the user at scheduled times as there is no guarantee they will arrive.
The question is what should i do, or what would you do in my case? No solution is perfect and i am hoping to find the most user friendly approach here. In case i am missing a approach, i would like to hear the alternative.
Edit:
Adding a another method for completeness.
UILocalNotification without repeats
don't offer the repeating of local notifications. The user can assign single Notifications to a event. After enabling the 65th notification, a popup will remind him that he has reached the system limit. This way you put the responsibility to the user. After reaching the limit he will be forced to focus on events that are not far in the future.
You could save all your events to core data and then every time the app is launched or when your main view appears load in all events for that week and set a scheduled local notification. Once the event is scheduled you set a flag in the entity eg hasBeenNotified.
Hope it helps.
I decided to offer local notifications without repeat functionality.
This decision was made after chatting with a few users.
Better to offer something than to offer nothing :)
Overview
I have an iOS app which sends local notifications at specific dates.
I just learned that I can only schedule 64 notifications at a given time.
There are cases when I can't schedule notifications as the 64 slots are filled.
So I store them in the database and when the user responds to a notification I check if there are any available slots and schedule the remaining notifications.
Problem
When the user doesn't respond to a notification my code is not executed so I am not able to schedule the remaining notifications.
Question
Is there a solution for this problem ?
can I execute a piece of code (house keeping) at certain times ?
is there any work around for this ?
You may not want to signal to the user there is a problem, but rather just do it in the background. If a user has 64 notifications for one app and hasn't opened the app, then they probably aren't using the app. Once a notification has fired it isn't in the array anymore. So you will have room every time a notification is fired off. They do however remain in notification centre, which you have to clear out yourself.
Its usually better to not present possible problems to the user, but rather handle them in a way that makes sense internally if that is an option. Look up the delegate methods for the appDelegate and you will most likely find ways you can handle what you are trying to do.
Thought I would make a post in case you wanted to accept the answer.
Best of luck.