Specifying Query Parameters for call: HTTP

[matthias-pichler]

What would you like to be added:

Would it make sense to add a structured way to add query parameters to uris when using call: http?

document: {}
do:
  - listPets:
      call: http
      with:
        method: get
        endpoint: 
          uri: https://petstore.swagger.io/v2/pets
        search:
          page[size]: ${ .pageSize }
          str: "Some string with characters & stuff that would need to be uri percent encoded! 👍 "

We could use the name "search", "query", "searchParameters", "queryparameters" or "parameters"

Why is this needed:

right now it is somewhat painful to specify these things using a runtime expression because we'd need to use the @uri format. And @uri also only encodes interpolated strings so the keys would have to manually encoded

document: {}
do:
  - listPets:
      call: http
      with:
        method: get
        endpoint: 
          uri: ${ @uri "https://petstore.swagger.io/v2/pets?page%5Bsize%5D=\(.pageSize)&str=\(\"Some string with characters & stuff that would need to be uri percent encoded! 👍 \")" }

[cdavernas]

@matthias-pichler-warrify you can also use top level args with { }, as demonstrated by https://github.com/serverlessworkflow/specification/blob/main/dsl-reference.md#http-call. I cannot find the place where this is documented, though I'd swear I wrote it.

As for uri encoding, I always assumed that was the responsibility of runtimes.

[matthias-pichler]

I only saw arguments under call: openapi but didn't find anything for call: http

[matthias-pichler]

@cdavernas

As for uri encoding, I always assumed that was the responsibility of runtimes.

In principle I am with you on this one but I am thinking of a case where the query parameter keys would also need encoding (e.g. page[size]). In this case the author would have to properly encode the square brackets when they include them in the uri.

I am also wondering how to elegantly handle array valued query params as there are different representations:

• repetition
• empty square brackets
• comma separated

Which could be handled with an appropriate field

[cdavernas]

@matthias-pichler-warrify fair enough, you make a very good point!

What about using query or queryParameters? Amongst your proposals, those are the terms that best represent imho the parameters we are trying to describe, though that's obviously opiniated and tainted by the techs I use.

On another note, I believe it would be awesome if the PR addressing the present issue would include documenting the ease of use feature I described in my last comment.

Wdyt?

[matthias-pichler]

On another note, I believe it would be awesome if the PR addressing the present issue would include documenting the ease of use feature I described in my last comment.

yeah the top level interpolation caught me by surprise when I first saw it 😅 Questions here:

• What if the top level attribute does not exist? empty result or expression error?
• can one use pet.id if pet is top level?
• what types are allowed and how are they serialized? specifically objects and arrays

[cdavernas]

What if the top level attribute does not exist? empty result or expression error?

In Synapse, if an expression fails to evaluate, we simply leave it as is. I'm however personally open to any and all suggestions!

can one use pet.id if pet is top level?

That's a very good and very subtle question. I would probably tend to say no, as if need be, one could always use the expression language interpolation feature if complex operations are required. I'm sure it would however be a great quality of life improvement, so we should probably restrict that feature to variable access, no matter the depth.

what types are allowed and how are they serialized? specifically objects and arrays

My take is that only primitive types should be allowed. In Synapse, we transform the result of the evaluation to a string, no matter the original type, so using complex objects or array would produce their string equivalency (which in .NET would be something like NameOfTheComplexObjectType)