Is there a way to get compojure-swagger to handle single value form parameters more gracefully when having only a single value?

I am using

:form-params [inputs :- [String] outputs :- [String] name :- String]

Hmh, not too familiar with form-params but I guess they are encoded like query params, thus collection with one item is the same as single input

It would need one item -> collection coercer for form-params

This is how it's done for query params: https://github.com/metosin/ring-swagger/blob/master/src/ring/swagger/coerce.clj#L99-L108

Compojure-api should already use query-schema-coercion-matcher for :form-params: https://github.com/metosin/ring-swagger/blob/master/src/ring/swagger/coerce.clj#L99-L108 https://github.com/metosin/compojure-api/blob/82e46fd801608dbcb457a763c7e629e8d859aa8b/src/compojure/api/meta.clj#L232

@trieloff: Which compojure-api version are you using?

I’m on 0.22.0

Hmm should work

Does this mean I should override the default coercion?

No

The default coercion should already be wrapping single items in collections for query and form params

Okay, looks like collections are not supported in url-encoded form-data currently

At least for swagger-ui generated requests

Yes, it looks like swagger-style requests key=value1,value2 is not enabled

In url-encoded form-data collections are encoded as comma separated string

This should be the split-params-matcher, correct?

Yeah

I don't remember exactly why it was commented out, but probably because there should be some way to control when it's used

As a quick fix you can set up custom coercer using split-params-matcher

Or use JSON params

And perhaps if you set swagger to use :collectionFormat multi it will generate requests with separate properties for each value

Hm, but switching from form-params to query-params has the same problem

?name=help&inputs=A1&outputs=A2&inputs=B1&outputs=B2 works fine, but don’t leave one out

According to Swagger-spec this should work: :form-params [x :- (field [String] {:collectionFormat "multi"})] and it generates valid swagger.json, but looks like Swagger-ui doesn't care about that

For now, I’m building the requests manually in curl – Swagger UI is secondary, but even then it fails unless I really have more than one value

Do you have a reason to use either form or query params?

body params work fine

Let me try that

With query-params, ?inputs=a and ?inputs=a&inputs=b should both give a vector

Body params works fine for me as well.

How to I use field https://clojurians.slack.com/archives/ring-swagger/p1444590854000049

I can’t find it in the docs and the compiler is complaining that it can’t find it either.

It's in ring.swagger.json-schema

(no wonder, if I can’t tell it where to look)

:query-params [x :- (js/field [String] {:collectionFormat "multi"})]

POST /formula/hans/*?x=A1 HTTP/1.1

{
  "errors": {
    "x": "(not (sequential? \"A1\"))"
  }
}

With multiple x parameters, it’s working.

Let me bump the version to 0.23.1

That seems to have helped. @juhoteperi – thanks for the help. I should have started with the version bump.

Oh right, now that I check changelogs, 0.23 entry mentions this

I’m definitely not working on this frequently enough. When I started, 0.22 was the latest version.

Now all that’s missing is split-params-matcher – but I can live with this and will watch out for 0.24