File upload, declaration via apiOperation (Swagger and Scalatra 2.6) - scala

Question

There is an existing project that uses Scalatra (2.6) and Swagger:
scalaMajorVersion = '2.12'
scalaVersion = "${scalaMajorVersion}.8"
scalatraVersion = "${scalaMajorVersion}:2.6.4"
compile "org.scalatra:scalatra-swagger_${scalatraVersion}"
I easily could add a new end point like:
get ("/upload", op[String]( // op finally invokes apiOperation
name = "Test method",
params = List(
query[Long]("id" -> "ID"),
query[String]("loginName" -> "login name")
),
authorizations = List(Permission.xxxxx.name)
)) {
...
}
but I cannot upload a file.
I expect to see a file selector button, but instead I see a single-line edit field.
(There are numerous things I'm uncertain about: form or file, [String] or [FileItem], which trait(s), what kind of initialization, etc.)
In the existing code I found a comment that someone could not get swagger to handle file upload. At the same time, I read that Scalatra and Swagger can do that, not all versions of them, but it looks like the version used in the project should be able to do that.
I could find code examples with yml/json interface definitions, but in the project there is no yml, only the apiOperation-based stuff.
Is there a working example using Scalatra 2.6, Swagger, and apiOperation?

Answer 1

I managed to get the file chooser (file selector, "Browse") button; there was no predefined constant (like DataType.String) for that. After I used DataType("File"), everything else just worked.
https://docs.swagger.io/spec.html says:
4.3.5 File
The File (case sensitive) is a special type used to denote file
upload. Note that declaring a model with the name File may lead to
various conflicts with third party tools and SHOULD be avoided.
When using File, the consumes field MUST be "multipart/form-data", and
the paramType MUST be "form".
post ("/uploadfile", op[String]( // op finally invokes apiOperation
name = "Upload File",
params = List(
new Parameter(
`name` = "kindaName",
`description` = Some("kindaDescription2"),
`type` = DataType("File"), // <===== !!!!!!
`notes` = Some("kindaNotes"),
`paramType` = ParamType.Form, // <===== !!
`defaultValue` = None,
`allowableValues` = AllowableValues.AnyValue,
`required` = true
)
),
consumes = List("multipart/form-data"), // <===== !!
...
)) {
val file: FileItem = fileParams("kindaName") // exception if missing
println("===========")
println("file: " + file)
println("name: " + file.getName + " size:"+file.getSize+" fieldName:"+file.getFieldName+ " ContentType:"+file.getContentType+" Charset:"+file.getCharset)
println("====vvv====")
io.copy(file.getInputStream, System.out)
println("====^^^====")
val file2: Option[FileItem] = fileParams.get("file123") // None if missing, and it is missing
println("file2: " + file2)
PS the apiOperation stuff is called "annotations".