Class NodeCreateRule.NodeBuilder

java.lang.Object

org.xml.sax.helpers.DefaultHandler

org.apache.commons.digester.NodeCreateRule.NodeBuilder

All Implemented Interfaces:

ContentHandler, DTDHandler, EntityResolver, ErrorHandler

Enclosing class:

NodeCreateRule

private class NodeCreateRule.NodeBuilder
extends DefaultHandler

The SAX content handler that does all the actual work of assembling the DOM node tree from the SAX events.

Since:

Digester 1.4

Field Summary

Fields

Modifier and Type	Field	Description
protected int	depth	Depth of the current node, relative to the element where the content handler was put into action.
protected Document	doc	A DOM Document used to create the various Node instances.
protected ContentHandler	oldContentHandler	The content handler used by Digester before it was set to this content handler.
protected Node	root	The DOM node that will be pushed on Digester's stack.
protected Node	top	The current top DOM mode.
protected StringBuffer	topText	The text content of the current top DOM node.

Constructor Summary

Constructors

Constructor	Description
NodeBuilder(Document doc, Node root)	Constructor.

Method Summary

Modifier and Type	Method	Description
private void	addTextIfPresent()	Appends a Text node to the current node if the content reported by the parser is not purely whitespace.
void	characters(char[] ch, int start, int length)	Handle notification about text embedded within the current node.
void	endElement(String namespaceURI, String localName, String qName)	Checks whether control needs to be returned to Digester.
void	processingInstruction(String target, String data)	Adds a new ProcessingInstruction to the current node.
void	startElement(String namespaceURI, String localName, String qName, Attributes atts)	Adds a new child Element to the current node.

Methods inherited from class DefaultHandler

endDocument, endPrefixMapping, error, fatalError, ignorableWhitespace, notationDecl, resolveEntity, setDocumentLocator, skippedEntity, startDocument, startPrefixMapping, unparsedEntityDecl, warning

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

oldContentHandler

protected ContentHandler oldContentHandler

The content handler used by Digester before it was set to this content handler.

depth

protected int depth

Depth of the current node, relative to the element where the content handler was put into action.

doc

protected Document doc

A DOM Document used to create the various Node instances.

root

protected Node root

The DOM node that will be pushed on Digester's stack.

top

protected Node top

The current top DOM mode.

topText

protected StringBuffer topText

The text content of the current top DOM node.

Constructor Details

NodeBuilder

public NodeBuilder(Document doc,
 Node root)
            throws ParserConfigurationException,
SAXException

Constructor.

Stores the content handler currently used by Digester so it can be reset when done, and initializes the DOM objects needed to build the node.

Parameters:

doc - the document to use to create nodes

root - the root node

Throws:

ParserConfigurationException - if the DocumentBuilderFactory could not be instantiated

SAXException - if the XMLReader could not be instantiated by Digester (should not happen)

Method Details

addTextIfPresent

private void addTextIfPresent()
                       throws SAXException

Appends a Text node to the current node if the content reported by the parser is not purely whitespace.

Throws:

SAXException

characters

public void characters(char[] ch,
 int start,
 int length)
                throws SAXException

Handle notification about text embedded within the current node.

An xml parser calls this when text is found. We need to ensure that this text gets attached to the new Node we are creating - except in the case where the only text in the node is whitespace.

There is a catch, however. According to the sax specification, a parser does not need to pass all of the text content of a node in one go; it can make multiple calls passing part of the data on each call. In particular, when the body of an element includes xml entity-references, at least some parsers make a separate call to this method to pass just the entity content.

In this method, we therefore just append the provided text to a "current text" buffer. When the element end is found, or a child element is found then we can check whether we have all-whitespace. See method addTextIfPresent.

Specified by:

characters in interface ContentHandler

Overrides:

characters in class DefaultHandler

Parameters:

ch - the characters from the XML document

start - the start position in the array

length - the number of characters to read from the array

Throws:

SAXException - if the DOM implementation throws an exception

endElement

public void endElement(String namespaceURI,
 String localName,
 String qName)
                throws SAXException

Checks whether control needs to be returned to Digester.

Specified by:

endElement in interface ContentHandler

Overrides:

endElement in class DefaultHandler

Parameters:

namespaceURI - the namespace URI

localName - the local name

qName - the qualified (prefixed) name

Throws:

SAXException - if the DOM implementation throws an exception

processingInstruction

public void processingInstruction(String target,
 String data)
                           throws SAXException

Adds a new ProcessingInstruction to the current node.

Specified by:

processingInstruction in interface ContentHandler

Overrides:

processingInstruction in class DefaultHandler

Parameters:

target - the processing instruction target

data - the processing instruction data, or null if none was supplied

Throws:

SAXException - if the DOM implementation throws an exception

startElement

public void startElement(String namespaceURI,
 String localName,
 String qName,
 Attributes atts)
                  throws SAXException

Adds a new child Element to the current node.

Specified by:

startElement in interface ContentHandler

Overrides:

startElement in class DefaultHandler

Parameters:

namespaceURI - the namespace URI

localName - the local name

qName - the qualified (prefixed) name

atts - the list of attributes

Throws:

SAXException - if the DOM implementation throws an exception