Dataflows Gen1 do not have a credential type option Web API for Web.Contents

[MartySchlafer]

Dataflows Gen1 do not have a credential type option Web API for Web.Contents.  Is this by design or is it emblematic of other subtle variances of Power Query in Power BI desktop, Power BI service, and Excel?

Other nuances...

• Custom Column modal has option to set data type of the new column in Power BI service but doesn't in Power BI desktop.  Interestingly, it does this by wrapping Table.AddColumn with Table.TransformColumnTypes.  Also, why doesn't use the fourth optional parameter of Table.AddColumn instead wrapping with Table.TransformColumnTypes?
• Power BI service has a display option for the schema.  Desktop doesn't... you have to temporarily add a step with Table.Schema...
  
  

[v-karpurapud · Accepted solution]

Hi @MartySchlafer 

Thank you for contacting the Microsoft Fabric Community Forum.

Currently, Dataflows Gen1 do not support the Web API credential type for use with the Web.Contents function. This is a known limitation, as Gen1 dataflows only allow a limited set of authentication methods: Anonymous, Basic, and Organizational Account (OAuth2).

Dataflows Gen2 in Microsoft Fabric do support Web API connections, but there are still some authentication limitations. The Web API connector in Gen2 supports only a few credential types: Anonymous, Basic (Username/Password), Organizational Account (OAuth2), and Windows. At this time, custom headers or bearer tokens for Web API authentication are not fully supported as they are in Power BI Desktop.

If your API requires advanced authentication, such as service principal or token-based headers, you may face restrictions with Dataflows Gen2. While Gen2 does offer improved connector support, Web API authentication options remain limited and may not cover all enterprise API integration requirements.

For additional details, please refer to the official Microsoft documentation provided below.
Set up your Web connection - Microsoft Fabric | Microsoft Learn

Regards,

Karpurapu D,

Microsoft Fabric Community Support Team.

 

[MartySchlafer]

Bummers.

[v-karpurapud]

Hi @MartySchlafer 

Thank you for posting your query in the Microsoft Fabric Community Forum, and thanks to @lbendlin  for sharing valuable insights.

Could you please confirm if your query has been resolved by the provided solution? This will help other community members solve similar problems faster.

Thank you.

[MartySchlafer]

There is no solution provided in thread yet...

[lbendlin]

Great questions, hopefully someone can shed some light on these.  I have an opinion on

Custom Column modal has option to set data type of the new column in Power BI service but doesn't in Power BI desktop.  Interestingly, it does this by wrapping Table.AddColumn with Table.TransformColumnTypes.  Also, why doesn't use the fourth optional parameter of Table.AddColumn instead wrapping with Table.TransformColumnTypes?

Most likely the Power Query engine doesn't care about that - it will rearrange steps and substitute functions as it sees fit.  You would have to use Query Diagnostics to see what actually happened and what the performance impact is.

[MartySchlafer]

@lbendlin 
Yes, however, if you leave the modal field for data type blank, it doesn't wrap with Table.TransformColumnTypes and matches the result of Power BI desktop.  Seems that they made a better modal (macro) and forgot to merge that code branch back into desktop.  This should be low hanging fruit and a huge win with the Power BI Community.  I hate adding the applied step to change data type from any to the real type.

[lbendlin]

"real type"  is very, very relative.  There is a massive disconnect between what column types Power Query supports and what column types Power BI (DAX) and Fabric support.

[MartySchlafer]

Data types in the context of Power Query naturally as that was the domain of the original post...  Power Query M type system - PowerQuery M | Microsoft Learn