E07790: Web Service parameter type cannot be HTTPRequest

What went wrong

A service parameter is typed HTTPRequest but is not bound with ':=: REQUEST' - it is a PATH, QUERY or HEADER parameter (the default for a path segment). Those bindings parse a single value from the request, so the parameter must be a simple type; the whole request is only available through ':=: REQUEST'. (The mirror case - ':=: REQUEST' on a non-HTTPRequest parameter - is E07770.)

Worked examples

Compilable examples demonstrating this error and the correct fix:

• ek9 -q 868 (Why can't I use HTTPRequest as a path parameter type in E...)

How to fix it

1. For a path/query/header value use a simple type: Integer, String, Date, Time, DateTime, Millisecond, Duration
2. If you need the whole request, bind it with ':=: REQUEST' as the only parameter

The [EXAMPLE] section below shows an HTTPRequest read from a query value, then the query read as a String and the whole request taken with ':=: REQUEST' in a method of its own.

Common causes

• HTTPRequest used as a path parameter type
• Wanting the full request in a method that also takes individual values

See also

• E07790: HTTPRequest without the REQUEST binding (this error)
• E07770: ':=: REQUEST' on a parameter that is not HTTPRequest
• E07760: the supported parameter types

Examples

Every example is compiled by the EK9 compiler: the first fails exactly as captioned, the others fix it.

Fails with E07790: Web Service parameter type cannot be HTTPRequest

#!ek9
defines module error.e07790.bad

  defines class

    TextResponse with trait of HTTPResponse
      text as String?

      default private TextResponse()

      TextResponse()
        -> body as String
        this.text: body

      override contentType() as pure
        <- rtn as String: "text/plain"

      override content()
        <- rtn as Bytes: Bytes().withUtf8(text)

      override status() as pure
        <- rtn as Integer: 200

      default operator ?

  defines service

    Addresses for :/addresses open

      search() as GET for :/search
        ->
          //A query value is text, never the whole request
          request as HTTPRequest :=: QUERY "q"
        <- response as HTTPResponse: TextResponse($request)

Fixed: Use HTTPRequest only with REQUEST

#!ek9
defines module error.e07790.good

  defines class

    TextResponse with trait of HTTPResponse
      text as String?

      default private TextResponse()

      TextResponse()
        -> body as String
        this.text: body

      override contentType() as pure
        <- rtn as String: "text/plain"

      override content()
        <- rtn as Bytes: Bytes().withUtf8(text)

      override status() as pure
        <- rtn as Integer: 200

      default operator ?

  defines service

    Addresses for :/addresses open

      search() as GET for :/search
        -> term as String :=: QUERY "q"
        <- response as HTTPResponse: TextResponse(term)

      whole() as POST for :/
        -> request as HTTPRequest :=: REQUEST
        <- response as HTTPResponse: TextResponse($request)

Questions and answers

These Q&A entries show E07790 and its fix:

• Q868: Why can't I use HTTPRequest as a path parameter type in EK9 services?