Update multiple items in SharePoint list when changing parent list item

[NickiPT]

Background: I am building my first app and it's a "parent" SharePoint list with 2 "child" lists. On my screens in the app I am using Forms to have the user submit and update the data to each of the lists. The child items are tied to the ID of the parent with a column called MasterID. A few key pieces of data from the parent list are also pushed to the child forms like the Employee Name (which is a people picker in the parent form but a text field in the child forms) and the person's office (which is a dropdown in the app but a text field in the parent and child lists).

Issue: What I can't figure out is how to do a bulk update of the child items if one of the key fields on the parent form gets updated. For example, if someone realized they had selected the wrong office from the dropdown in the app, upon clicking "SAVE CHANGES" I want all of the related child items to get updated.

Screen 1: Parent Form

Screen 2: Child Form #1 with filtered gallery showing all child forms related to the parent

Screen 3: Child Form #2 set up the same way as #1

Screen 4: A gallery that shows all of the parent list items

I have researched Filter, ForAll, Patch, LookUp, ClearCollect, Collect...and I can't figure out what the right order is to set up my formulas so that this works and I don't have to worry about delegation issues.

OnSelect of my gallery that shows all records, I have:

Set(varID, galRecords.Selected.ID); Set(varMode, "View")

OnVisible of Screen #1 I have:

If(

varMode <> "New",

ClearCollect(

colQuals,

Filter(QualsList, MasterID = varID)

)

)

And that works to create a collection of the results from Child List #1 that match the ID from the parent list. But would this give me issues with delegation? And then what's my next step? Should I put something OnChange of the individual fields in the parent form? Or a formula OnSelect of the "SAVE CHANGES" button?

I put this formula OnChange of one of the key fields on the parent form and it updated only the FIRST matching item it found in the child list:

If(varMode <> "New", 

ForAll(

colQuals,

Patch(

ChildList, 

LookUp(

ChildList,

MasterID = varID

),

{DutyStation: inpDutyStation.text}

)

)

)

What am I missing? Help please!!

[C-Papa · Accepted solution]

Hi, the best way to do this is use the UpdateIF() 

you will need to put a condition to decide if the UpdateIF runs or you could run it every time. the formula is...

UpdateIf(ListName,ID = MasterID,{Title:"test"}) 

where Title:"test" is the column title and test is the update. you can add more using the same syntax as the patch function

[zmansuri · Accepted solution]

If you want the Common field between child and parent to be consistent.

OnSuccess of your Main Form:

UpdateIf(ChildList,LastSubmit.ID=MasterID,PatchCode here for all the common fields)

That way every time someone submits main form it will go and update the common fields from master to child no matter they are changed or not.

[NickiPT]

Thank you both @C-Papa  and @zmansuri! I put the following formula at the end of my OnSuccess formula and it worked!

UpdateIf(

ChildList,

ParentForm.LastSubmit.ID = MasterID,

{DutyStation: inpDutyStation.Text}

)

So will this not have any issue with delegation? In the Microsoft documentation for UpdateIf it says "When used with a data source, these functions can't be delegated..."

[NickiPT · Accepted solution]

@C-Papa  and @zmansuri - I just watched this video from Shane Young about UpdateIf not being delegable: https://www.youtube.com/watch?v=zINTAUJqQhg

And I ended up with this formula instead which also works and according to him is delegable:

ClearCollect(

colQuals,

Filter(

ChildList,

MasterID = ParentForm.LastSubmit.ID

)

);

ForAll(

colQuals As QualsData,

Patch(

ChildList,

QualsData,

{DutyStation: inpDutyStation.Text}

)

)

[CindyZ]

This worked out perfectly for me!  Thanks so much for taking the time to share how you solved your problem along with help from others!