User-Defined Function w/ List Parameter

[markew1]

When I pass a list to a user defined function (shown in Excel above) I get a Choose Column button upon invocation to specify a table column rather than a field to provide a list reference.  Why is this?  Are lists not supported?  Is my parameter declaration incorrect?

As an aside, I should mention that I did see a Chris Webb blog entry that describes the behavior that I show above.  He shows how this behavior can be used to good effect; however, I want to pass a "list of lists" as an argment and have the user-defined function process it as is.  Why can't I do that?

[Anonymous]

@markew1,

In Chris's blog, when clicking "Choose Column", all of the values from that column will be passed as a list in the function.

Could you please share sample data and post the expected result ? And how about you use parameter in Power BI Desktop? There is another Chris's blog about defining parameter in Power BI Desktop for your reference.

In addition, for Power Query issues, you can post questions in Power Query forum to get better support.

Regards,
Lydia

[markew1]

Lydia, thanks for the reply.  I didn't find Chris's blog on parameters very helpful in the circumstances that led me to post my concern.  Let's say that I have shared a user-defined function via my Data Catalog, and that function is designed to accept a list of lists ( e.g., {{"A","apple"},{"B","banana"},{"C","cherry"}} ) rather than a table.  Now when a less sophisticated user attempts to add a custom table column by invoking my user-defined function ( using the Add Column Invoke Custom Function ribbon tool ) they are prompted for a table column to be passed as an argument rather than the intended list of lists.  Shouldn't the invocation recognize that such a circumstance could exist, and allow for a drop-down list of all list objects as well as a drop-down list of tables from which a single column could be selected?

[markew1 · Accepted solution]

I've added a UserVoice entry requesting changes to the invocation dialog to support stand-alone lists as well as a table column.  

https://ideas.powerbi.com/forums/265200-power-bi-ideas/suggestions/32987845-user-defined-function-in...

I would appreciate your Vote if you agree with this needed change.