Can't delete collection on an offline mobile device

[EA10]

the following scenario and problem:

I am currently creating an app with a form for recording contacts. This app needs to be offline capable, so the required master data (company name, first name, last name, etc.) comes from an Excel form, which is fed with data from our ERP system. To ensure an offline function I save the data in a collection which is created at the start of the app using the function "ClearCollect". Saving to the collection and then uploading to the sharepoint list works fine. However, the problem is that the collection is not cleared with the Remove or Clear functions.

This creates the following situation:

Person A records 5 contacts, uploads them to the sharepoint list as soon as he has internet -> we have 5 entries in the list.

Person B takes 7 contacts and uploads them to the sharepoint list e.g. 15min later -> we have 17 entries in the list, because he takes the 5 contacts of person A into his own collection and uploads them again.

Performed attempts:

- A single "Clear" (with the function "Clear") button that is only supposed to clear the Collection didn't work on the mobile devices.

- A new "ClearCollect" function after uploading the data to the sharepoint didn't work either.

The only thing that works is the "Clear" button on the PC when I open the app in edit mode. Then all content within the Collection is deleted, both on the PC itself and on the mobile devices.

I would like to be able to completely clear the Collection with the mobile devices, so that I can clear the Collection again after each update on the mobile devices.

Would be happy if someone has a solution for this, so slowly I despair with the subject.

[Anonymous]

Not directly a solution to your problem but could be a workaround.

Why don't you introduce an extra column into your collection which indicates whether the contact was created locally or not? This way when you synchronise to your SP list you can limit the sync to those what were created locally. 

And maybe you could then also use this extra column to keep track of which contacts have not yet been synchronised by deleting the flag for those which have been sent already, in case you have a connection which keeps dropping out. You wouldn't have to sync the field to the SP list, just track it locally.

[AkshayR]

Always try to use SaveData, LoadData and Cleardata Functions while dealing with offline apps as the data gets managed on the local storage. It will avoid interference of multiple data of various persons.

[EA10]

But can i upload the data from the local storage to my sharepoint list after the devices have an internet conection? I thought i can only do that from a collection. 
The data are first saved in the local storage with SaveData, after that i patch them into the collection and then i patch the collection in a sharepoint list. If i can patch the local data directly in the sharepoint list then this would solve my problem, i guess.

sorry im pretty new at powerapps 😄

[Anonymous]

Don't think you can upload the data straight from local storage to SP lists, my understanding is that you need to load it into a collection first.

Anyway, I just tried this and it worked. Created 3 buttons with the following OnSelect code for each.

Create Collection:

ClearCollect(
    MySampleCollection,
        {LocalTime: Text(Now(),"mm:ss")}
)

Patch Collection:

Patch(
    'MySampleCollection',
    Defaults('MySampleCollection'),
        {
            LocalTime: Text(Now(),"mm:ss")
        }
)

Clear Collection:

Clear(MySampleCollection)

All 3 buttons worked as expected on both my desktop and my mobile device (Android), this through the PowerApps app.

[EA10]

This could maybe help. My collection is created via the "onStart" function of the app and this could may be the issue. I'll try it, thanks 🙂