Request Element

For request payloads, one or more cm-request elements follow the cm-header element in the cm-payload root element. These elements specify the operations which are to be executed by the CMS server.

<!ELEMENT cm-request (%cm.cm-request;)>
<!ATTLIST cm-request
  request-id CDATA #REQUIRED
  preclusive (true | false) "false">

The subelements of the cm-request element are defined in CRUL. The corresponding DTD is explained in the XML Reference. A cm-request element has the following attributes:

• request-id
  Request ID. This ID is issued by the creator of the request payload. It must be unique within all payloads that are exchanged in a particular communication context. It is not sufficient that the ID is unique within the current payload.
• preclusive
  Truth value (true or false). The preclusive attribute allows the NPS client to mark the requests which are critical for the continued processing of payloads. If the processing of a request marked as preclusive fails, all further requests in the payload are not processed but are answered with an error message.

All requests in a payload are processed in sequence beginning with the first request. In this way, it is possible for a client to put together requests that are dependent on each other in one request payload. For example, in a single payload, a client can first create a file format and then create files based on this format. Using the preclusive attribute, the client can also ensure that the dependent request is only processed when the previous one has not caused an error.