[AXIOM-335] DataHandler extension should support deferred loading/parsing

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.2.8
• Fix Version/s: 1.2.9
• Assignee: Andreas Veithen
• Reporter: Andreas Veithen
• Created: 06/Jul/09 20:32
• Updated: 28/Nov/11 23:41
• Resolved: 07/Jul/09 20:27

Description

The XMLStreamReader extension defined by the IS_DATA_HANDLERS_AWARE, IS_BINARY and DATA_HANDLER properties (see OMConstants) currently only allows immediate loading of the DataHandler. This extension could be leveraged in a wider range of use cases if it also allowed deferred loading of the DataHandler: in this case the consumer of the XMLStreamReader would get a reference/link to the binary data but would fetch the DataHandler only when required (as Axiom does when processing an MTOM/XOP message).

This improvement could be implemented by defining a set of additional properties, but a purely property based solution is not very usable, difficult to document and also not very efficient. The proposal is therefore to define an extension interface (with methods isBinary(), isDeferred(), getDataHandler(), etc.) as well as a single property that allows the consumer of the XMLStreamReader to query that extension interface. Of course care would be taken to maintain compatibility with the existing DataHandler extension.

Issue Links

• blocks: AXIOM-255 The sequence of events produced by OMStAXWrapper for XOP:Include is inconsistent