How can I stop phone screen from turning off?

[BenGin]

I have a Canvas App built to be used on a phone. I have a button to send the data to the Dataverse. This can take some time. However, because it takes some time, the iPhone screen turns off and the Power App gets interrupted and the data write fails.

Is there a way to set the iPhone screen to not turn off if there is a process running, so, like a piece of code I can put in the "OnSelect" of the button at the top and bottom that will set the phone to not turn off the screen until it reaches the end of the code?

[Pstork1 · Accepted solution]

Apple doesn't provide an API to turn off the screen shutdown.  You can do it manually in the settings, but there is no way to do it programmatically. The only way Apple made it possible was in Objective C when writing a native app.

[BenGin]

Hi, thanks for the fast response. This is going to be a real pain. The end users are not the most tech savvy, and they need to use this app in areas where there is little to no connectivity. Hence I have built this app to store data in the offline cache. This is why it takes a long time to send the data to the Database when they finally get into an area with connectivity.

[Pstork1]

The app should keep running even when the screen shuts down.  If they press the Power button it should open the app right where they left off.  If they are then in an area with connectivity it should pick up and download the data.  

[BenGin]

Interesting, because it didn't work when I tested it. When I pressed the Power button and turned the phone back on, the Power Apps showed a warning message (I don't remember exactly what). Then it appeared to continue to execute the code (I have an overlay rectangle that only disappears after the OnSelect code has finished). This overlay disappeared, but the data is not in the Database. At the end of the OnSelect code, I remove it from the cached Collection, so those records have disappeared off the phone too.

So, to clarify, I am not downloading data from the Dataverse to the phone. I am trying to Patch data from the phone into the Dataverse.

[Pstork1]

I thought you were saving the data locally? and then patching back to Dataverse when you were online.

How long does the patch take to run?  Yes, I believe there will be a problem if the patch() is in the middle of running when the phone shuts down.  But you don't want a patch that runs that long anyway.  If the patch completes before the phone shuts down or goes offline it shouldn't be a problem.

[BenGin]

Thanks for taking the time to respond again.

Correct, I am saving data locally into Collections and using the "SaveData" function to ensure the Collections retain data between sessions.

Then, when back online, a button will have the DisplayMode set to Edit and the user can then tap the button to Patch.

The Patch can take a minute or two depending on the amount of data.

The use case is:

1. The user can initiate multiple "Parent" records (one for each activity they are doing) which are then stored in a Collection
2. There are also two "Child" tables that are set up in the Dataverse with "Many-to-One" relationships back to the "Parent"
3. One of the "Child" tables is to hold Photos taken by the user
4. Because of the relationships, when I patch all the "Parent" records, I need to return their Records to attach to each of the "Child" records with the correct relationship back to the "Parent".

All of these contribute to the Patch taking a lengthy amount of time.

It doesn't help that a "ForAll" is not a proper "For" loop and I cannot use "Set", or "ClearCollect", so I had to be creative with the code and Collections to be able to match the "Child" record to the "Parent" and ensure integrity when Patching the "Child" tables.

Added to the complexity is dealing with records that can be loaded from the DB that can then be edited, and must also stored in the Offline Collections but with Patch code to deal with the fact they are already in the Database compared to other Records that are purely local device only.

So much for Microsoft's "Low Code" platform!

[Pstork1 · Accepted solution]

I normally avoid using the ForAll() to do patches for this very reason.  Instead, I would send the collection to a Power Automate flow to do the patching.  I would do the same for loading data.  Flows have much better capabilities for handling large complex databases without having to worry about delegation issues.  Since you are using Dataverse the need for a Premium license to receive a data set from Power Automate shouldn't be an issue.  Properly designed this can be much faster than doing it in Power Apps and it has the advantage that the flow should keep running even if Power Apps goes offline (once the raw dataset has been transmitted)

[Pstork1]

Just to add.  Low code platforms have always had issues with really complex data operations.  That's not just Microsoft.  Thats true for all of them.  But they aren't primarily designed for professional developers or those kinds of situation.  Its the old 80/20 rule.  80% of development in low code can be done quite easily, but 20% is almost easier to do using traditional development.

[BenGin]

I hear you. It comes down to Stakeholder management that what they want may not be possible or at the very least, not easy to implement and then likely with limitations. Then there needs to be a compromise, or if those requirements are "must haves", then Power Apps is not the right tool.