E07791: Web Service parameter type must be HTTPContext for CONTEXT

What went wrong

You're using CONTEXT parameter binding but the parameter type isn't HTTPContext. The CONTEXT qualifier provides access to the request context (authenticated principal, security state, connection metadata).

Worked examples

Compilable examples demonstrating this error and the correct fix:

• ek9 -q 1329 (Why must a CONTEXT-bound service parameter be typed HT...)

How to fix it

1. Use HTTPContext type with :=: CONTEXT
2. For individual values, use specific access types (:=: QUERY, :=: PATH)

The [EXAMPLE] section below shows ':=: CONTEXT' on a String, and on an HTTPContext.

Common causes

• Using String or other types with CONTEXT qualifier
• Confusion between CONTENT (String body) and CONTEXT (request metadata)

See also

• E07791: Wrong type for CONTEXT (this error)
• E07792: HTTPContext mixed with other params
• E07793: HTTPContext with wrong access type
• E07770: Similar - wrong type for REQUEST

Examples

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

Fails with E07791: Web Service parameter type must be HTTPContext for CONTEXT

#!ek9
defines module error.e07791.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

      info() as GET for :/info
        ->
          //CONTEXT is an HTTPContext
          context as String :=: CONTEXT
        <- response as HTTPResponse: TextResponse(context)

Fixed: Take CONTEXT as an HTTPContext

#!ek9
defines module error.e07791.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

      info() as GET for :/info
        -> context as HTTPContext :=: CONTEXT
        <- response as HTTPResponse: TextResponse($context)

Questions and answers

These Q&A entries show E07791 and its fix:

• Q1329: Why must a CONTEXT-bound service parameter be typed HTTPContext in EK9?