XMLOptimizedContent

Set on STRING or BYTE data type so that such string content represents a file on disk to be transmitted as base64 binary in SOAP via HTTP attachment.

The XMLOptimizedContent attribute is allowed on BYTE or STRING data type.

The XMLOptimizedContent attribute adds value when used in one of these scenarios:

When MTOM is enabled and the XMLOptimizedContent attribute is set on a BYTE, it sets the variable that must be transmitted transparently as an HTTP part on the wire. See Message Transmission Optimization Mechanism (MTOM) for more information.
When MTOM is enabled and the XMLOptimizedContent attribute is set on a STRING, it contains the name of the file to be transmitted as a Base64 binary, with an optional mime-type hint, in order to avoid loading a file in a BYTE. See Message Transmission Optimization Mechanism (MTOM) for more information.
If the XMLOptimizedContent attribute is set to "swaRef" (XMLOptimizedContent="swaRef") and set on a STRING, the contents of the file are transmitted according to the SoapWithAttachmentRef specification. See swaRef (SOAP with attachments using wsi:swaRef) for more information.

If the XMLOptimizedContent attribute is set on a 4GL STRING data type, it is expected to contain the name of the file that the Genero Web Service will load based on the current directory during transport of the MTOM request.

If the XMLOptimizedContent attribute is set on a 4GL STRING data type, it will contain the absolute path of the file GWS has received during the transport of a MTOM response. The absolute path is based on the Genero temp directory settings and contains a UUID generated name. The programmer is in charge of moving the file or removing the file from disk.

The optional value is a hint to specify the mime-type of the data. The hint may be used by Java or .NET to generate different kinds of objects, depending on the information provided by the hint. For instance, on Java a mime type of "image" will generate a java.awt.Image object instead of a byte[] object.

Example

The Genero code:

DEFINE rec RECORD
  data1 BYTE ATTRIBUTES(XMLOptimizedContent,XMLName="MyData"),
  date2 STRING ATTRIBUTES(XMLOptimizedContent="image/*",XMLName="MyImage"),
  data3 BYTE
END RECORD

The XSD representation:

<xsd:complexType name="rec">
  <xsd:sequence>
    <xsd:element type="xsd:base64Binary" name="MyData"/>
    <xsd:element xmime:expectedContentTypes="image/*" type="xsd:base64Binary" name="MyImage"/>
    <xsd:element type="xsd:base64Binary" name="data3"/>
  </xsd:sequence>
</xsd:complexType>

Things to observe:

With the BYTE data type, regardless of whether the XMLOptimizedContent attribute is set, the same type (xsd:base64Binary) appears in the XSD.
The STRING holds the path to the document to transfer and is viewed as a BYTE in the XML exchange.
With the STRING data type, a mime type is specified.