Can query parameters be applied to functions?

[otravers]

I have a function that retrieves data from a web API. One of the fields to be passed to the API accepts just two values, "10-Q" and "10-K". I've read the blog posts about parameters and created a parameter list with these two values, but is there a way to use that parameter right in the function definition (i.e. not in a downstream query)? This would work as a form of data validation when the function is invoked.

Screenshot below to try and clarify what I mean:

 

[Anonymous]

Hi otravers

Try this code:

= (ticker as text) as table =>
let
FormTypes = "10-Q",
order = "10-K", 

    Source = Json.Document(Web.Contents("https://services.last10k.com/v1/company/" & ticker & "/balancesheet?formType=" & FormTypes & "&filingOrder=" & order, [Headers=[#"Ocp-Apim-Subscription-Key" = "redacted"]])),
    #"Converted to Table" = Record.ToTable(Source),
    #"Transposed Table" = Table.Transpose(#"Converted to Table"),
    #"Promoted Headers" = Table.PromoteHeaders(#"Transposed Table")
in
    #"Promoted Headers"

I couldn't test it properly, as I don't have permission for this site.

[otravers]

Hp Pfister, order is a separate variable. What you're doing just hardcodes "10-Q" as the value for FormTypes, while what I'm looking for is a way to restrict input for FormTypes to its two valid values, 10-Q and 10-K.

smoupre, thanks but it looks too complicated for my purposes. I'll live with M's limitations 🙂

[Greg_Deckler]

I do not believe that is a proper use case for parameters. I think you would be better off just coding it into your fucntion, something like:

values = {"10-Q", "10-K"}

And then just validating against that list.

For more on parameter use cases, I would refere to this excellent series of blog posts:

http://biinsight.com/power-bi-desktop-query-parameters-part-1/

[otravers]

OK, I did some more reading on function syntax but didn't find how to "just code" the acceptable values into the function using an array as you suggested. May I ask where you'd put it in the following code?

let
    Source = (ticker as text, FormTypes as text, order as text) as table =>
let
    Source = Json.Document(Web.Contents("https://services.last10k.com/v1/company/" & ticker & "/balancesheet?formType=" & FormTypes & "&filingOrder=" & order, [Headers=[#"Ocp-Apim-Subscription-Key" = "redacted"]])),
    #"Converted to Table" = Record.ToTable(Source),
    #"Transposed Table" = Table.Transpose(#"Converted to Table"),
    #"Promoted Headers" = Table.PromoteHeaders(#"Transposed Table")
in
    #"Promoted Headers"
in
    Source

[GilbertQ · Accepted solution]

Hi @otravers

I think that you can put your variable as part of your function in your code below.

let
    Source = (ticker as text, FormTypes as text, order as text) as table =>
let
    Source = Json.Document(Web.Contents("https://services.last10k.com/v1/company/" & #"ticker" & "/balancesheet?formType=" & #"FormTypes" & "&filingOrder=" & order, [Headers=[#"Ocp-Apim-Subscription-Key" = "redacted"]])),
    #"Converted to Table" = Record.ToTable(Source),
    #"Transposed Table" = Table.Transpose(#"Converted to Table"),
    #"Promoted Headers" = Table.PromoteHeaders(#"Transposed Table")
in
    #"Promoted Headers"
in
    Source

What I have done is to change it from your parameters in your Source line which might work?

    Source = Json.Document(Web.Contents("https://services.last10k.com/v1/company/" & #"ticker" & "/balancesheet?formType=" & #"FormTypes" & "&filingOrder=" & order, [Headers=[#"Ocp-Apim-Subscription-Key" = "redacted"]])),

[Greg_Deckler]

Here is an example:

https://community.powerbi.com/t5/Community-Blog/Using-Recursion-to-Solve-Hex-to-Decimal-Conversion/b...