WSOptional

Qualifies a parameter as optional in a REST function.

Syntax

WSOptional

WSOptional is an optional attribute.

Usage

You can set WSOptional on the ATTRIBUTE()clause of a parameter when a function does not require the parameter to be present when a client calls the service. Setting parameters as optional is typically used when defining REST functions in the following situations:

If a query string (WSQuery) is not always required, set the input parameter with WSOptional. For an example, see Example use of parameter attributes.
If a custom header (WSHeader), input or output, is not always required, set the parameter with WSOptional. For an example, see Example use of parameter attributes.
If a cookie (WSCookie) is not always required, set the parameter with WSOptional. See Example: Optional cookie.

Example: Optional cookie

IMPORT  com

TYPE profileType RECORD
     id INT,
     name VARCHAR(50),
     email VARCHAR(100),
     ccode VARCHAR(10)
     # ...
   END RECORD

DEFINE myError RECORD ATTRIBUTE(WSError="My error")
  code    INTEGER,
  reason  STRING
END RECORD

PUBLIC FUNCTION getUsersByCountry(
     p_country STRING ATTRIBUTE(WSCookie, WSOptional, WSName = "Preferred_country" ) )
  ATTRIBUTES (WSGet, 
              WSPath="/users",
              WSDescription="Get users by country if the cookie is sent by client.",
              WSThrows="400:Invalid,404:NotAvailable" )
  RETURNS (
    DYNAMIC ARRAY ATTRIBUTE(WSName="Users",WSMedia="application/xml,application/json") OF profileType 
    )
  
    DEFINE countryList DYNAMIC ARRAY OF profileType
    IF p_country IS NULL THEN
        SELECT * FROM users 
    ELSE 
        SELECT * FROM users WHERE @ccode=p_country
    END IF
     # ... function code  ...
    RETURN countryList
END FUNCTION