Access the HTTP headers request and response at server side

In high level web services, we now give access to the HTTP headers request and response.

The web service can get information from the request headers and reply with custom headers and status.

Declare variables to receive or send HTTP headers.
Register these variables to the web service server.

Declare variables to receive or send HTTP headers

The variable for the request headers:

DEFINE http_in RECORD
           verb  STRING,
           url   STRING,
           headers DYNAMIC ARRAY OF RECORD
                 name  STRING,
                 value  STRING
                 END RECORD
           END RECORD

After the web service operation has been processed, the variable is set to NULL.

The variable for the response headers:

DEFINE http_out RECORD
           code INTEGER,
           desc STRING,
           headers DYNAMIC ARRAY OF RECORD
                 name  STRING,
                 value  STRING
                 END RECORD
           END RECORD

After the web service operation has been processed, the variable is set to NULL.

Note: While the variables must follow the structure shown, the variable name can be any name you choose.

The web service engine headers have precedence. For example, if you set the "Content-Length" value, the one that is taken into account is the one defined by the Genero Web Services engine.

Register the variables to the server

This code example uses two methods, which use the defined variables:

com.WebService.registerInputHttpVariable(http_in) where http_in is the RECORD variable for the request headers.
com.WebService.registerOutputHttpVariable(http_out) where http_out is the RECORD variable for the response headers

Example

FUNCTION CreateService()

  DEFINE serv com.WebService     # WebService
  DEFINE op com.WebOperation     # Operation of a WebService

  TRY

    #
    # Create a Web Service
    #
 
    LET serv = com.WebService.CreateWebService("EchoHttpHeadersService",
 Namespace) 
 
    #
    # Create Document Style Operations
    # 
      
    # EchoDOCRecord
    LET op = com.WebOperation.CreateDOCStyle("echoDocRecord",
"EchoDOCRecord",echoRecordDoc_in,echoRecordDoc_out)
    CALL serv.publishOperation(op,NULL)
 
    # Register HTTP input
    CALL serv.registerInputHttpVariable(http_in)
    
    # Register HTTP output
    CALL serv.registerOutputHttpVariable(http_out)
    
    #
    # Register service
    #
  
    CALL com.WebServiceEngine.RegisterService(serv) 
    DISPLAY "EchoHttpHeadersService Service registered" 
  CATCH 
    DISPLAY "Unable to create 'EchoHttpHeadersService' Web Service :
",STATUS||" ("||SQLCA.SQLERRM||")"
    EXIT PROGRAM (-1) 
  END TRY    
END FUNCTION 

FUNCTION echoDocRecord() 
  DEFINE  ind INTEGER 
  DEFINE  ok  BOOLEAN
 
  # Check incoming VERB
  IF http_in.verb != "POST" THEN
    LET http_out.code = 400
    LET http_out.desc = "Bad request: method should be POST"
    RETURN 
  END IF 

  # Check incoming query string 
  IF http_in.url.getIndexOF("?MyQuery=OK",1)<=0 THEN
    LET http_out.code = 400
    LET http_out.desc = "Bad request: URL should have MyQuery=OK"
    RETURN 
  END IF 

  # Check incoming header called MyPersonal 
  LET ok = FALSE 
  FOR ind = 1 TO http_in.headers.getLength()
    DISPLAY ind||"# ",http_in.headers[ind].name,
"=",http_in.headers[ind].value
    IF http_in.headers[ind].name == "MyPersonal" THEN
      IF http_in.headers[ind].value == "Header" THEN     
        LET ok = TRUE   
      END IF
    END IF 
  END FOR 
  IF NOT ok THEN
    LET http_out.code = 400
    LET http_out.desc =
 "Bad request: expected additional header called MyPersonal"
    RETURN 
  END IF 

  # assign the output record 
  LET echoRecordDoc_out.MyRecord.MyInt =
 echoRecordDoc_in.MyRecord.MyInt 
  LET echoRecordDoc_out.MyRecord.MyFloat =
 echoRecordDoc_in.MyRecord.MyFloat 

  # Add MyPersonalHeader=MyPersonalValue http headers 
  LET http_out.headers[1].name = "MyPersonalHeader" 
  LET http_out.headers[1].value = "MyPersonalValue"

END FUNCTION