Building a source document from lexical XML
The conversion of lexical XML to a tree in memory is called parsing, and is performed by a software component called an XML Parser. Saxon does not include its own XML parser, rather it provides interfaces that invoke XML parsers supplied by third parties. Platforms such as Java and .NET typically include a built-in XML parser that Saxon uses by default.
A source document can be built using the
PyDocumentBuilder in Python), which is created using the factory method
NewDocumentBuilder() in C#, and
new_document_builder() in Python) on the
SaxonProcessor in C++ and PHP,
PySaxonProcessor in Python). Various options
for document building are available as methods on the
DocumentBuilder, for example options
to perform schema or DTD validation, to strip whitespace, to expand XInclude directives, and also to
choose the tree implementation model to be used.
On Java, the different ways of supplying input to the DocumentBuilder
are represented using the JAXP
Source object. This is a JAXP interface designed
as an abstraction of various kinds of XML source, including:
StreamSource, which represents lexical XML held in a file or input stream.
SAXSource, which represents a source of SAX events.
DOMSource, representing an already-parsed XML document held in a DOM tree.
StAXSource, which represents a class that responds to requests for STAX (pull-parser) events.
- ActiveSource, a Saxon extension of the JAXP
Sourceinterface, allowing you to define your own kind of input source: all you need to do is implement the method
deliver(), which delivers the contents of the resource to a Saxon
- NodeInfo, representing a node in an XDM tree, implements
In addition, the s9api XdmNode class has an
so it is always possible to supply an existing Saxon tree as the source for any of these interfaces.
On .NET, the DocumentBuilder has an overloaded
allowing input to be supplied from sources of the following kinds:
Stream, containing lexical XML as a stream of bytes.
TextReader, containing lexical XML as a stream of characters.
Uri, which can be dereferenced to fetch a stream of bytes.
XmlNode, Microsoft's DOM implementation.
XmlReader, an XML parser, primed with a source of input.
On C++, Python and PHP, source XML documents can be parsed from file or lexical string using methods on the
- In C++, DocumentBuilder provides the methods:
- In Python, PyDocumentBuilder provides the method
parse_xml()with which different keywords are used to supply the input from file, URI or lexical string.
- In PHP, Saxon\DocumentBuilder provides the methods:
It is also possible to parse XML documents directly from the
DocumentBuilder, using the methods of the same names as above. However this only
allows simple parsing, not any of the additional parsing options available with
All the documents processed in a single transformation or query must be loaded using the same
Configuration. However, it is
possible to copy a document from one
Configuration into another by supplying the
TreeInfo at the root of the
existing document as the
Source supplied to the
method of the new
With SaxonC, it is only possible to copy a document from one
into another by serializing the object and parsing it again.