Parent/Child New Form question/issue

[javierC]

Hello! I have a Parent/Child New Form question/issue
 
I have two sharepoint lists. One called Projects (id, name, status, etc) and the other one called ProjectTasks (id, project_id, name, etc). The ProjectTasks list has a reference field called project_id, which I am using for the Parent/Child relationship between the projects and the tasks. So the projects can have many tasks.

The App that I created is very simple; it has a  GalleryProject screen where you can see all the projects. If you go into a projects, you can view the project details; and if you click on the tasks icon you can see all the tasks related to the project. Ideally, I would like to be able to create new task and make sure that this new task is referenced back to the project_id. (parent).  
 
I have a screen called NewTask where I have a NewTaskFrom with all the Task information, including a Drop Down called Project_ID that list all the projects (remembers, this is a reference field to Projects list)

Show ProjectList Related task and Add new Task ButtonAdd new Task form and Parent ID
 

 
The challenge I am having is that I am unable to set/ auto-selected the NewTaskFrom.Project_ID dropdown with the ProjectGallery.Selected.ID.
 
I tried to change the Default value to “ProjectGallery.Selected.ID” which it seems to work. However, when I try to submit the form I get an error as if the Project_ID dropdown is empty.  I have tried many things, but still have not been able to do it. 
 
I was wondering if anyone had the same issue and can share a workaround. Thanks!

[mabolan]

I verified that @ExtJac's solution works. He correctly found out that the lookup field is supposed to be sent over as a record while also defining the data type it is using...

'@odata.type':"#Microsoft.Azure.Connectors.SharePoint.SPListExpandedReference"

if you want to make sure that PowerApps continues to show the correct value within your PowerApp, you can set the dropdown values like so...

The PowerApps team is currently working on making relationships and lookups easier for CDS. As we refine the experience there, we hope to do the same for SharePoint and SQL. Until then, I'll work with the documentation team to come up with an walkthrough for this very common scenario.

[ExtJac]

The new issue i found now is that the new records are not being listed on the Task list...even using the refresh button. However, if i go to the sharepoint list i can see the record was created with a parent Id .

By the way..I am javierC...the one that started this post but for some reason i cant login so I am using extjac.

[mabolan]

Good to know you're the same person 

I ran into the same refresh issue when I was replicating the initial issue. The solution is to make sure the refresh button is refreshing the correct data source. You'll want the OnSelect property of the refresh button to be the following:

Refresh(Parent);Refresh(Child)

I also opted to refresh the child data sources as soon as the form is submitted by changing the OnSelect property of the submit button to the following:

SubmitForm(ChildForm);Refresh(Child);Navigate(ParentScreen,None)

[CW]

Great stuff. It seems the lookup field is problematic on all platforms even its native SharePoint. Once you get the syntax it can be pretty powerful manipulation of a useful control.

Funny the refresh was mentioned as I was wondering about implementing it but never saw it referenced in any of the MS examples so just forgot about it. I figured it was being handled internally and invoking it again may be a needless or repetitve call.

Cheers.

CW

[CW]

Update. I have a meeting scheduled with an MS support engineer this week and hope to get to the bottom of this and will mention all the ideas everyone in this forum have contributed.

CW