SharePoint list custom forms not working

[NewToPowerApps]

We have two SharePoint lists on a site, call them List1 and List2.  List2 contains a text field containing names of people (Name, but also the Title) and a Boolean field indicating whether they have died (Deceased).  List1 has among other fields a Person field with a lookup to Azure AD (Person) and a field that looks up the names of people in List2 (Visited), allowing several to be selected.  I wanted to filter out the deceased from the selections available in Visited.  I quickly abandoned customising the .aspx files using SharePoint Designer 2013 as instructions on the internet appeared obsolete.  It seemed that PowerApps was the right approach, but I have hit several issues. I have had many attempts at getting this to work, and may now have ended up with a corrupt PowerApps environment.

Isssues:

1. The out of the box custom form for List1 only puts the Person and Visited fields on the form.  When I first tried this, all the custom fields were put on the form.
2. Attempting to save a new value fails with a possible data source error.
3. The out of the box fields don't recognise the other data sources:
   Person Item Formula is of the form Choices([@List1].Person) - no reference to the AD lookup, so presumably you can only enter people who are already in List1.
   Visited Item formula is of the form Choices([@List1].Visited) - no reference to List2, so presumably you can only enter Visited who are already in List1.
4. Changing this to Choices(List2.Name) results in a Name isn't valid error, despite Name being in the selection lists for List2 fields.

Hence, I am stuck, and am tempted not to put more effort the project as the issue is not so great.  It does, however, make me hesitate to recommend SharePoint custom lists (as opposed to other ways of storing data that might me more familiar to end users) and attempting to use PowerApps to manage them.

Any comments?

[WarrenBelz]

Hi @NewToPowerApps ,

Firstly, the "out of the box solution" (I am assuming you are referring to the app generated from the wizard) is really only to start you on the PowerApps journey and is a good place to start looking at the properties and the controls to see "what is under the hood".

Connecting to a second data source and then working out what to do with it is another part of the journey. You did not say what your background was, but I came from VBA/SQL/Access and PowerApps was a bit of an adventure of discovery.

Having said that, two years down the track, I would not use anything else - but enough of that and to your issue.

Firstly, PowerApps/SharePoint has a thing called Delegable and non/Delegable queries. Non-Delegable can only retrieve a maximum of 2000 records to PowerApps. I mention this because Boolean values (such as Deceased Yes/No) are non-delegable and cannot be queried on large datasets - you would need a string field such as Deceased/Living.

I am not sure what else I can tell you at your early stage of this path other then good luck.

[Pstork1]

1. When you create a custom list form inside a SharePoint list it only adds the fields to the form that are editable by the user in that list.  System fields like Created, Modified By etc. are not added by default. You can add additional fields from that list to the form by editing the fields in the forms.
2. I need more info to figure out what might be going wrong here.  Can you provide a screenshot of your custom form and the specific error message.
3. The Person field is actually a lookup against the hidden user list in the site collection, not against Azure AD.  The original info comes from Azure AD, but that's not what the person field is checking against.  Having said that, fields from other lists will be outside the scope of this particular form.  You would need to add a second data source to the other list to access those values.  This does not limit you to List 1, it limits you to the Choices that are defined in that column in List1.  For Person that would be anyone with access to the list (from the userlist) and for Visited it would be anyone who is listed in the column being used for the Lookup in List 2.  But you can't change that here.  Choices() pulls those from the column definition.
4. See #3. The Choices are based on the column definition, not the list.

Having said all that.  The custom list form works very well when all you want to do is create a customized data entry form for the existing list.  Creating a data entry form that spans multiple lists is a more advanced concept and not easy to do.  It will take some work and there is a learning curve involved.

[NewToPowerApps]

Thank you, @WarrenBelz, for a quick response.  I have a varied IT background with VB, C#, various SQL databases, Visual Studio, Access, PHP etc.  I have programmed using Visual Studio and NetBeans.

I recognise that the custom form generated by the wizard is only the start, otherwise there would be no point in generating it, but I should expect it to work as generated.  I should also expect it to read enough information from the SharePoint list to understand the structure of the list.  Neither appears to be the case at the moment with the list I am attempting to work on.  I am wondering if I need to recreate List1 and copy the data from the current one.

The datasets are tiny, so Delegable is irrelevant.

It is a pity you can't see further 'under the hood' to see what is going wrong.

[NewToPowerApps]

Thanks @Pstork1 for a helpful reply.  To explain a bit more and to reply:

1. I am not trying to add system fields.
2.  I am attaching the custom form as generated by PowerApps
3.  The SharePoint list which I am calling List1 has choices based on the values in List2. I realised that you needed another data source and had added it.
4.  Even the form as created with the wizard and published (I had to add another field to be able to save and publish) fails to update with this message:
   
5.  I am concerned that the environment may be corrupt, as this is the save window.  Notice the ID in the name.
   
I have spent long enough (four or five days) trying to solve what I thought would be a simple problem, but must now give it up as I have other priorities.  I can only conclude that in my hands PowerApps isn't working and we shall have to live with the slight loss of functionality.

[Pstork1]

If you want to keep trying to work on this please provide the following. A screenshot of the column definitions in List 1 and List 2 (List Settings screen)

1) What addditional fields are you trying to add?

2) The attachment didn't come through

3) If you have a lookup column in List #1 that references List #2 you don't need to add an additional data source.  Any references that List #1 needs to List #2 will already be embedded in the column definition for List #1.  If you want to access values directly in List #2 then you need a different data source. But the Lookup should work without it.

4) What field did you add to get it to save?

If you don't want to pursue this further due to time constraints, I understand.  

[NewToPowerApps]

List 1 column settings:

Column (click to edit) Type Used in

Arrival Time	Single line of text	Item
Client deceased now?	Yes/No	Item
Created	Date and Time
Departure Time	Single line of text	Item
Home Communion	Number	Item
Location	Choice	Item
Modified	Date and Time
Notes	Multiple lines of text	Item
title	Single line of text	Item
Visit Date	Date and Time	Item
Visited	Lookup	Item
Visited by	Person or Group	Item
Visited:Deceased (Text)	Lookup
Created By	Person or Group
Modified By	Person or Group

List2 Column settings

Column (click to edit) Type Required

Name	Single line of text
Married to	Lookup
Appointed Visitor	Person or Group
Deceased	Yes/No
Notes	Multiple lines of text
Deceased (Text)	Calculated (calculation based on other columns)
Alive	Calculated (calculation based on other columns)
Modified	Date and Time
Created	Date and Time
Created By	Person or Group
Modified By	Person or Group

Custom form screen shot

All I am trying to do is to filter the Visited dropdown to so the Deceased don't appear in it when someone is entering a new record in List 1.

[Pstork1 · Accepted solution]

Ok, I put together a quick POC from your list definitions. 

1) Not sure why, but when you originally create the custom form it does indeed only auto populate a couple of fields.  But you can easily edit the form and add any other fields you want.  Make sure to add any fields from List 1 that were marked as required. See the screenshot below

2) for the choice filter you will need to add a data source for List #2 to the project and then use the following code in the Items property for the dropdown in the datacard.  The Choices still point to List1, but are filtered based on the name being in a list of people in List 2 who are not deceased.  Your formula may vary slightly if my column names don't match yours exactly.  But that is how to do it.

Filter(Choices([@List1].Visited),Value in (Filter(List2,Deceased=false).Name))

Hope that helps.  Let me know if you are still having issues.

[NewToPowerApps]

Many thanks, @Pstork1 !  It was the Value in (Filter(List2,Deceased=false).Name)) that clinched it.  It now appears to be working.   Wonderful!