Hi all
Running into some strange behavior when using the First or FirstN functions in PowerApps.
I have a data table control in the PowerApp that shows a filtered and sorted data source (SharePoint list). The filtering is based on a variable (we'll call it var_Item_Num) that the user enters. The formula looks like this:
=SortByColumns(Filter(My_Data_Source,Item_Number_Column = var_Item_Num), "Date_Time",Descending)
Works fine -- as soon as the user changes var_Item_Num, the data table updates. If the var_Item_Num is not found within the source, the data table is blank/empty. Great.
Next I wanted to use the same filter, but only return the first/most recent row to the data table. This is where I'm running into issues. Tried with both First/FirstN like so:
=First(SortByColumns(Filter(My_Data_Source,Item_Number_Column = var_Item_Num), "Date_Time",Descending))
This is fine if var_Item_Num is found -- the most recent result is returned. However the behavior changes when var_Item_Num is not found; instead of showing blank, the data table just doesn't update. It shows whatever the previous result was. For example if I search 1111 and view the first result, then search 2222 which is not in the data source, the result for 1111 is still shown.
If I remove First, this behavior is corrected immediately -- a search for 1111 and then 2222 will yield an empty data table as expected.
For kicks I also tried using a collection as a data source instead of the sharepoint list, but had the same result.
Any idea why is this happening?
