Issue with Patch(Datasource, Collection)

[aktuzad]

Hi

I've been using a button with

Patch(
Activities;
Filter(
TempTblActivities;
Created <> Blank()
));;

to save changes done to multiple records back to a sharepoint list for quite a while now, but yesterday i ran into issues in the editor.

Suddenly the Patch would not fire any more in my current edit, so I checked the older published version and Patch seemed to work.

I restored that older version, opened it in the editor, but no, the Patch-function did not work. I published that version in case the problem only existed in the editor, but no, still didn't work. I've been messing around in the monitor to see what actually happens, but theres no data operation with patch.

I restored back to the older published version again, published it without the editor and now it works as published, but not in editor mode.

I all out of ideas. Maybe sharepoint changed? Maybe powerapps changed? The only difference between my current version of the app, and the one that worked earlier is that modern controls have replaced the old ones. 

[WarrenBelz]

Hi @aktuzad ,

I am assuming 'TempTblActivities' is a collection ? If so for that structure to work every field in the collection needs to exist in both name and field type in Activities. Have you changed anything in either of them ? Also are you getting any errors in the code ?

[aktuzad]

No errors.

Yes, TempTblActivities is a collection. In Onvis, I first 

ClearCollect(
TblActivities;
Filter(
Activities;
Name= User.Name
));;

Then I ClearCollect(TempTblActivities;TblActivities);;

There was a reason for the use of two similar collections, I believe it was necessary to have one to show data (TblActivities) and one to handle the changes locally (TempTblActivities), before patching to Sharepoint list (Activities).

[aktuzad · Accepted solution]

@WarrenBelz 

I've changed 

Patch(
Activities;
Filter(
TempTblActivities;
Created <> Blank()
));;

to

ForAll(Filter(
TempTblActivities;
Created <> Blank());
Patch(
Activities;
ThisRecord
));;

which seems to be working. This would indicate that the collection; TempTblActivities, and the datasource, Activities, use the same field types and names, right? 

I've been trying to follow guidance from Matther Devaney and Reza Dorrani, and allthough Patch(datasource,collection) might be "undocumented", its been working fine until recent. And like I mentioned, the current published app works, but when editing that version it does not work, and not when publishing that edit. Patch(datasource,collection) doesnt seem to fire any more. 

[WarrenBelz]

@aktuzad ,

Interesting as both codes are doing essentially the same thing, except ForAll is a bit more explicit. I have not struck the issue with the the collection direct and use it a bit myself in apps. You can also do this

Collect(
   Activites,
   Filter(
      TempTblActivities;
      Created <> Blank()
   )
);

but that may not work if the Patch is not - so I suggest you stay with what you have.

[aktuzad]

@WarrenBelz 

How does this work?

Collect(
   Activites,
   Filter(
      TempTblActivities;
      Created <> Blank()
   )
);

Seeing you have Created <> Blank() this would not create new items in the datasource, right? So you can use collect to "patch" changes to existing items?

Ill keep trying to find the reason for this sudden change and will update this thread if so. 
Thank you so much for your help so far, Warren!
 

[StevenRichards]

One other way to write your formula that avoids writing to read only columns in SharePoint is to specify the columns you do have write access to:  (note the ID column is not optional. It replaces the filter you have on created <> Blank().

Patch(
    SharepointList,
    ShowColumns(
        colSharepointList,
        ID,
        Title,
        Name,
        Place,
        Thing
    )
);

[WarrenBelz]

Hi @aktuzad ,

It is just an alternative to Patch where you are sending all the records from TempTblActivities where the Created field is not blank to Activities. To be honest, I generally "future proof" my code (who knows what will be added / changed in the future) and Patch fields that could be changed explicitly - I assume you have the ID in the collection

Patch(
   Activities;
   ForAll(
      Filter(
         TempTblActivities;
         Created <> Blank()
      ) As _Data;
      {
         ID: _Data.ID;
         FirstField: _Data.FirstField;
         SecondField: _Data.SecondField;
         . . . . . . .
      }
   )
)

I will offer some fundamental advice here that may assist with this and future ForAll() exercises. It is not designed to be a Loop, although it can work this way with considerable performance penalty as it does an individual Patch for each record. ForAll() creates a Table, which can be patched in one action provided its content is correct. For new records, this is simply a Table with field names and field types matching the list. For existing records, including the SharePoint record ID in the table causes it to update that record for each of the Table records.

[MrGrumpyGuy]

I am having this exact same issue as of three days ago. Have been using Patch(List,Collection) as it is faster than ForAll(Patch( but now it is not working

[WarrenBelz]

@MrGrumpyGuy ,

I have found that has broken a few times before, hence I take the time to do explicit (and always reliable) patches.