How to show child items in DetailScreen

[AriGunawan]

Hi,

I have two SharePoint lists as the data sources for a PowerApps app.

Let say they are ParentList and ChildList.

Every item in ChildList relates to one item in ParentList via ParentItem field, so one item in ParentList can relate to multiple ChildList items.

I'm trying to show the child items in the DetailScreen of ParentList item.

I've added a datatable in the DetailScreen.

Then I set its Items property to:

Filter(ChildList, ParentItem.Id = ThisItem.ID)

in order to filter the ChildList data.

The datatable doesn't show the expected result.

It seems that the datatable item is not dynamically changed/refreshed based on the current ParentList item.

I was wondering if anyone had the same issue and can share a workaround.

Thanks!

Update:

Using the same datasource and filter, a Gallery could display child items correctly.

But I still need to display the child items in a datatable

[BitLord69]

Do you have the childlist in each row of the Parent gallery, or just one data table that shows the currently selected Parent? I think you mean the second option, so then you have to use the selected row from the gallery:

Filter(ChildList, ParentItem.Id = ParentGallery.Selected.ID)

A screen shot could clarify a lot.

Good luck!

[Delid4ve]

Be carful using this method tho, I've already submitted a bug where on an iOS device when clicking say an arrow in a gallery to navigate it doesn't actually select the gallery item.

Your better off setting a variable to thisItem.fieldname and filtering the table based on this variable

So arrow:
Set(myvariable,ThisItem.ParentID);Navigate(detailsScreenName,ScreenTransition:None)

And on the data table use ParentId=myvariable in the filter

[AriGunawan]

Hi,

Thanks for your suggestion.

That's right, I have one list to store all child items of the ParentList item. I've updated the initial post with screenshot of my data sources.

I've tried your suggestion.

I've checked that I got the parent gallery's selected id.

However, the datatable still doesn't updated accordingly.

You could see the screenshot below, the child datatable still shows the child of the "Parent 2" item.

[AriGunawan]

Hi,

Thanks for your suggestion.

Store the parent id in variable using Set or UpdateContext

then use it in the filter logical_test, still not update the child datatable.

[Delid4ve]

On your list I see you are using the title field.
You need to store the ID of the parent item in the child table.
On your SharePoint list go to modify view, then look down the column list and find ID and put a tick in the box.

The way it is at present you need to use:
Filter(childlist,Parentitem = gallery.Selected.Title)

You need to get your data structure right:
Child table should have a number column, parentID, and in this store the ID of the parent item.

[AriGunawan]

We don't need to store the parent id because the ParentItem field in the child table is a lookup object, not a primitive value.

So it always has an Id stored.

To confirm that, I added a new screen to show the ChildList item filtered by a parent item id (1).

The datatable shows the expected result: only show items that have Parent 1 in ParentItem

I think the Filter function is used correctly.

The problem is the datatable is not updated when the value (gallery.Selected.Id/global variable/screen context) inside the Filter function changed.

[Delid4ve]

There could be a few issues:

1:I believe powerapps doesnt handle sharepoint lookups correctly, from when i last looked at this.

2:I had the issue of datatables not refreshing correctly also, you can get around this by setting the items property of your datatable to a variable, say: TableItems, then on your gallery navigate button/arrow add in 

Set(TableItems,Filter(ChildList,ParentID=Gallery.Selected.ID))

See how you get on with that

[AriGunawan]

The datatable still not updated.

This is the result on Parent 2 item details screen: (it should shows Child 2.1 item)

Even though the TableItems variable has the correct items

also when I open the Data section of the child datatable, it always shows "Updating fields" state.

[Delid4ve]

Just for testing add another column into your child list and set as type number and populate with the ID of the parent.  Then do the filter on this field.  Im 99.99% certain its to do with this lookup.