Documentation about query folding with OnSelectedRows

[fmms]

Hi,

we are just developing a custom connector on a REST API. This API allows me to iterate over several products and get values for each of them.

Let's imagine the API has two functions getAssets() and getAssetHistory(product).

getAssets()

-Asset-   | 
M1        | 
M2        | 
M3        | 

getAssetHistory(asset)

-Asset-   | -Date-   | -Value- | 
M1        | 1.1.2020 | 5       |
M2        | 1.2.2020 | 5       |
M3        | 1.3.2020 | 5       |
M4        | 1.4.2020 | 5       |
M5        | 1.5.2020 | 5       |

We have built a connector that works in Import mode and that does

History = Table.AddColumn("Assets", "History", each getAssetHistory([asset]))      

We now have to support query folding on the Asset column and later on the date column.

To my understanding for this we have to implement the onSelectectedRow handler of Table.View. However, today my hope for documentation vanished https://github.com/MicrosoftDocs/powerquery-docs/issues/49 .

Let's imagine as a user I go to the Transform Data experience and there I filter on two Assets (e.g. M1,M2). Now within the connector I want to be able to skip the call getAssetHistory(M3) as this result will not be needed at all.

Could you please give some guidance where to look, happy to provide more details and engage in personal conversations.

#318 is actually quite similar...

@cwebbbi , @CurtHagenlocher