Set a request body

Functions that create or update a resource need to set a request body for the incoming payload. You specify the request body in an input parameter.

Typically, you specify an input body parameter when you perform an HTTP PUT, POST, or PATCH request to a resource, otherwise you get error-9106. However, you can set WSOptional on the ATTRIBUTES(). For a sample function, see Set a request body as optional.

In your BDL function, you specify a request body by declaring an input parameter that does not have any WSHeader, WSQuery, WSCookie, or WSParam attributes.

If you have more than one of such input parameters, it means your payload is delivered in a multipart body request.

Example specifying a request body

In this sample REST function a user record is updated with a value sent in the request body. The function's id parameter specifies the user to update. The lname parameter of type STRING provides the user details to update.

If the data type is not a primitive data type, you may need to define a type suitable for the structure in your module. The function needs to receive data of the required structure in either a JSON or XML representation. For an example, see Example: create resource with WSPost.

WSThrows is set to handle errors. In the TRY/CATCH block, the sqlca record is checked after the execution of the SQL query. The SQLERRMESSAGE is set to the message field of the userError variable, and a call to SetRestError() returns the message defined in WSThrows for the error.

IMPORT com

PUBLIC DEFINE userError RECORD ATTRIBUTES(WSError = "User error")
  message STRING
END RECORD

PUBLIC FUNCTION updateUsersField(
    id INTEGER ATTRIBUTES(WSParam, WSDescription = "User id"),
    lname STRING ATTRIBUTES(WSDescription = "User's last name"))
  ATTRIBUTES(WSPut,
             WSPath = "/users/{id}",
             WSDescription = "Update name of a given user",
             WSThrows = "400:@userError")
  RETURNS STRING
    DEFINE ret STRING
      TRY
        UPDATE users
        SET name = lname WHERE @id = id
        IF sqlca.sqlerrd[3] = 1 THEN # sqlerrd[3] = processed rows
          LET ret = SFMT("Updated user with ID: %1",id)
        ELSE
          LET ret = SFMT("No user with ID: %1",id)
        END IF
      CATCH
        LET ret = SFMT("Error updating user with ID: %1",id)     
        LET userError.message = SFMT("SQL error:%1 [%2]",
                                     sqlca.sqlcode, SQLERRMESSAGE)
        CALL com.WebServiceEngine.SetRestError(400,userError)
      END TRY
    RETURN ret
END FUNCTION
Figure: Output of the HTTP request

Sample output of the HTTP request