User Data Functions, List Slicer, and Select All

[omnipotamus]

I have created a user data function that takes input from a list slicer, button slicer, and a text slicer. It creates a row in a SQL database for each item selected in the list slicer. This is working as expected.

However, if I try to use Select All in the list slicer, the button to submit becomes disabled with a message that something needs to be selected in the list (despite the fact that everything is selected in the list). I've found in searching that PBI treats select all as select none, which makes sense in other contexts, but not here. I've been trying to come up with a workaround, such as selecting all except one and then saving with that as the default state, but it's behaving unexpectedly.

Is there a way to use the list slicer with user data functions without the user having to select items one by one?

And/or, is there a way to use the list slicer with UDF and multiple fields in the list? The list stops showing up as an option for the data function when I add more than one field.

[burakkaragoz]

Hi @omnipotamus ,

Yeah, this is a known quirk with list slicers and user data functions in Power BI. When you hit "Select All," Power BI actually treats it as “none selected” in the backend, which breaks UDF submission (the button gets disabled). There’s no native fix—users have to manually pick items.

Workarounds people use:

• Tell users to select all items manually (not ideal, I know).
• Sometimes you can pre-select all but one, save that as default, and instruct users to add the last one, but it’s clunky.
• No way right now to use "Select All" and have it behave as expected with UDFs.

For your second question:
If you add multiple fields to the list slicer, it stops supporting UDFs—this is also a current limitation. Only one field in the slicer works with user data functions.

Not perfect, but that’s the state of things. If you want, you can add an idea in the Power BI forums for better support!

Let me know if you want help with any specific workaround.

[v-aatheeque]

Hi @omnipotamus ,
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