Multidimensional arrays as parameters.

[IvanGoncharov]

Currently Swagger 2.0 support specs like that:

{
    "swagger": "2.0",
    "info": {
        "version": "0.0.0",
        "title": "Simple API"
    },
    "paths": {
        "/{foo}": {
            "parameters": [
                {
                    "name": "foo",
                    "in": "path",
                    "type": "array",
                    "items": {
                      "type": "array",
                      "items": {
                        "type": "string"
                      }
                    }
                }
            ],
            "get": {
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        }
    }
}

By default collectionFormat is csv and this create problems with interpreting strings like 'a,b,c,d'.
Should it be interpreted like:

[
  ["a","b","c","d"]
]

Or maybe like this:

[
  ["a", "b"],
  ["c", "d"]
]

It should be forbidden to create nested arrays with same collectionFormat.
This change will prevent undefined behaviour situation and could be done in 2.0 as bugfix.
JSON Schema couldn't enforce such constraints, but it could be specified in spec.

[jharmn]

Link to parent #565

[fehguy]

Done in #804

[ePaul]

@fehguy I don't actually see this in the specification ... where do we forbid this (which would be the corresponding structure to what @IvanGoncharov posted)?

parameters:
  - in: path
    name: foo
    schema:
      type: array
      items:
        type: array
        items:
          type: string
    example: 'a,b,c,d'
    required: true

[fehguy]

we don't forbid this, we support it by allowing a schema object as the type for the parameter.

[ePaul]

The original issue said

It should be forbidden to create nested arrays with same collectionFormat.

While the original code was not actually valid in OpenAPI 2.0, I think, its transformed version is valid in OpenAPI 3.0-RC0 due to the introduction of schemas for parameters.

Now there isn't a collectionFormat anymore, but the style property, which only applies on top level.

So for style: simple (which is the default for path parameters) there is still no way of knowing whether /a,b,c,d would be parsed as [["a","b"],["c","d"]], as [["a","b","c","d"]] or as any other structure.

There doesn't even seem to be a way of using different styles for both levels of array (which could solve this potentially).

So I think the issue is still open.