E07793: Web Service parameter type cannot be HTTPContext

What went wrong

You're using HTTPContext type but not with CONTEXT access type. HTTPContext can only be used with :=: CONTEXT, not with QUERY, PATH, HEADER, or CONTENT.

Worked examples

Compilable examples demonstrating this error and the correct fix:

• ek9 -q 1331 (Why can't I bind HTTPContext to a QUERY parameter in a...)

How to fix it

1. Use :=: CONTEXT for HTTPContext parameters
2. Or use appropriate type for the access type

The [EXAMPLE] section below shows an HTTPContext read from a query value, then the context taken with ':=: CONTEXT' and the query read as a String.

Common causes

• HTTPContext with wrong access type (:=: QUERY, :=: PATH)
• Confusion about access type requirements

See also

• E07793: HTTPContext with wrong access type (this error)
• E07791: Similar - wrong type for CONTEXT
• E07790: Similar - HTTPRequest with wrong access type

Examples

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

Fails with E07793: Web Service parameter type cannot be HTTPContext

#!ek9
defines module error.e07793.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
        ->
          //A query value is text, never the context
          context as HTTPContext :=: QUERY "q"
        <- response as HTTPResponse: TextResponse($context)

Fixed: Use HTTPContext only with CONTEXT

#!ek9
defines module error.e07793.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)

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

Questions and answers

These Q&A entries show E07793 and its fix:

• Q1331: Why can't I bind HTTPContext to a QUERY parameter in an EK9 service?