Third-party Object Models: Axiom, DOM, JDOM, JDOM2, XOM, and DOM4J
This section is relevant to the Java platform only.
In the case of DOM, all Saxon editions support DOM access "out of the box", and no special configuration action is necessary.
Support for Axiom, JDOM, JDOM2, XOM, and DOM4J is not available "out of the box"
with Saxon-HE, but the source code is open source (in sub-packages of
and can be compiled for use with Saxon-HE if required.
The support code for Axiom, DOM4J, JDOM, JDOM2, and XOM
is integrated into the main JAR files for Saxon-PE and Saxon-EE, but (unlike the case of DOM) it is not activated
unless the object model is registered with the
Configuration, which can be done either by including it in the
relevant section of the configuration file, or by nominating it using the method
Each supported object model is represented in Saxon by a
object, which in the case of external object models will also be an instance of
can be used to get a
Builder, which can then be used to construct an instance of the model
from SAX input. The
Builder can also be inserted into a pipeline to capture the output of
a transformation or query.
For DOM input, the source can be supplied by wrapping a
DOMSource around the DOM
Document node. For Axiom, JDOM, JDOM2, XOM, and DOM4J the approach is similar, except that the wrapper classes are supplied
by Saxon itself: they are
respectively. These wrapper classes implement
NodeInfo interface (which means that they also implement
Saxon supports these models by wrapping each external node in a wrapper that implements
NodeInfo interface. When nodes are returned by the XQuery or XPath API, these
wrappers are removed and the original node is returned. Similarly, the wrappers are generally removed when
extension functions expecting a node are called.
In the case of DOM only, Saxon also supports a wrapping the other way around: an object implementing
the DOM interface may be wrapped around a Saxon
NodeInfo. This is done when Java methods expecting a
DOM Node are called as extension functions, if the
NodeInfo is not itself a wrapper for a DOM
You can also send output to a DOM by using a
DOMResult, or to a JDOM tree by
JDOMResult, or to a XOM document by using a
In such cases it is a good idea to set
xsl:output to ensure that the
transformation or query result is a well-formed document (for example, that it does not contain
several elements at the top level).
External object models do not in all cases fully support the XDM (XPath data model). In particular, many of them have restrictions concerning the recognition of ID and IDREF attributes. None of the external object models support typed (schema-validated) data, and none support in-situ update using XQuery updates.