Hi,
I am trying to build a custom data connector that lets users navigate a folder structure on the local machine/network and import selected Excel Tables into PBI. The below example line "source = Excel.Workbook(File.Contents(url), null, true)" works without a problem using Windows authentication with "Use my current credentials" when executed directly in a Power BI Desktop query. However, when executed from within my custom data connector I receive the error message "Please specify how to connect" in the Connection dialog in PBI:
[DataSource.Kind="PQExtension1", Publish="PQExtension1.Publish"]
shared PQExtension1.File = (path as text) as table =>
let
source = Excel.Workbook(File.Contents(path), null, true)
in
source;
Data Source Kind is configured like this:
PQExtension1 = [ Authentication = [
Windows = [
// This key brings up the 'Use current credentials' and 'User Name' etc. edit boxes in the credential dialog in PBI
SupportsAlternateCredentials = true ] ],
Label = Extension.LoadString("DataSourceLabel") ];
Note, that it fails with the same error message also if I supply a user name and password instead for authentication.
I have also tried to send the current credentials to the File.Contents method File.Contents(path, Extension.CurrentCredential()). But this only results in the error "2 arguments supplied to a function that only expects one" - even though the documentation clearly states that File.Contents can accept a record as a second parameter.
What am I missing? I would be realy grateful if somebody could help me out with this authentication problem!
Edit :: I found the following text in the documentation at https://docs.microsoft.com/en-us/power-query/handlingdataaccess#data-source-kind:
"Currently, a limited set of data source functions have been enabled to support extensibility.
So the basic data access functions, such as File.Contents(), are not supported for data connectors...?
