/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/*
* $Id: DOMBuilder.java 472634 2006-11-08 20:43:55Z jycli $
*/
package org.jbpm.xml;
import java.util.Stack;
import java.util.Vector;
import org.w3c.dom.CDATASection;
import org.w3c.dom.Document;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.Text;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.Locator;
import org.xml.sax.ext.LexicalHandler;
/**
* This class takes SAX events (in addition to some extra events that SAX
* doesn't handle yet) and adds the result to a document or document fragment.
*/
public class DomBuilder implements ContentHandler, LexicalHandler {
/** Root document */
public Document m_doc;
/** Current node */
protected Node m_currentNode = null;
/** The root node */
protected Node m_root = null;
/** The next sibling node */
protected Node m_nextSibling = null;
/** First node of document fragment or null if not a DocumentFragment */
public DocumentFragment m_docFrag = null;
/** Vector of element nodes */
protected Stack m_elemStack = new Stack();
/** Namespace support */
protected Vector m_prefixMappings = new Vector();
/** to obtain the line number information */
protected Locator locator = null;
/**
* DOMBuilder instance constructor... it will add the DOM nodes to the
* document fragment.
*
* @param doc
* Root document
* @param node
* Current node
*/
public DomBuilder(Document doc, Node node) {
m_doc = doc;
m_currentNode = m_root = node;
if (node instanceof Element)
m_elemStack.push(node);
}
/**
* DOMBuilder instance constructor... it will add the DOM nodes to the
* document fragment.
*
* @param doc
* Root document
* @param docFrag
* Document fragment
*/
public DomBuilder(Document doc, DocumentFragment docFrag) {
m_doc = doc;
m_docFrag = docFrag;
}
/**
* DOMBuilder instance constructor... it will add the DOM nodes to the
* document.
*
* @param doc
* Root document
*/
public DomBuilder(Document doc) {
m_doc = doc;
}
/**
* Get the root document or DocumentFragment of the DOM being created.
*
* @return The root document or document fragment if not null
*/
public Node getRootDocument() {
return (null != m_docFrag) ? (Node) m_docFrag : (Node) m_doc;
}
/**
* Get the root node of the DOM tree.
*/
public Node getRootNode() {
return m_root;
}
/**
* Get the node currently being processed.
*
* @return the current node being processed
*/
public Node getCurrentNode() {
return m_currentNode;
}
/**
* Set the next sibling node, which is where the result nodes should be
* inserted before.
*
* @param nextSibling
* the next sibling node.
*/
public void setNextSibling(Node nextSibling) {
m_nextSibling = nextSibling;
}
/**
* Return the next sibling node.
*
* @return the next sibling node.
*/
public Node getNextSibling() {
return m_nextSibling;
}
/**
* Return null since there is no Writer for this class.
*
* @return null
*/
public java.io.Writer getWriter() {
return null;
}
/**
* Append a node to the current container.
*
* @param newNode
* New node to append
*/
protected void append(Node newNode) throws org.xml.sax.SAXException {
Node currentNode = m_currentNode;
if (null != currentNode) {
if (currentNode == m_root && m_nextSibling != null)
currentNode.insertBefore(newNode, m_nextSibling);
else
currentNode.appendChild(newNode);
// System.out.println(newNode.getNodeName());
} else if (null != m_docFrag) {
if (m_nextSibling != null)
m_docFrag.insertBefore(newNode, m_nextSibling);
else
m_docFrag.appendChild(newNode);
} else {
boolean ok = true;
short type = newNode.getNodeType();
if (type == Node.TEXT_NODE) {
String data = newNode.getNodeValue();
if ((null != data) && (data.trim().length() > 0)) {
throw new org.xml.sax.SAXException("Warning: can't output text before document element! Ignoring...");
}
ok = false;
} else if (type == Node.ELEMENT_NODE) {
if (m_doc.getDocumentElement() != null) {
ok = false;
throw new org.xml.sax.SAXException("Can't have more than one root on a DOM!");
}
}
if (ok) {
if (m_nextSibling != null)
m_doc.insertBefore(newNode, m_nextSibling);
else
m_doc.appendChild(newNode);
}
}
}
/**
* Receive an object for locating the origin of SAX document events.
*
* <p>
* SAX parsers are strongly encouraged (though not absolutely required) to
* supply a locator: if it does so, it must supply the locator to the
* application by invoking this method before invoking any of the other
* methods in the ContentHandler interface.
* </p>
*
* <p>
* The locator allows the application to determine the end position of any
* document-related event, even if the parser is not reporting an error.
* Typically, the application will use this information for reporting its own
* errors (such as character content that does not match an application's
* business rules). The information returned by the locator is probably not
* sufficient for use with a search engine.
* </p>
*
* <p>
* Note that the locator will return correct information only during the
* invocation of the events in this interface. The application should not
* attempt to use it at any other time.
* </p>
*
* @param locator
* An object that can return the location of any SAX document event.
* @see org.xml.sax.Locator
*/
public void setDocumentLocator(Locator locator) {
this.locator = locator;
// No action for the moment.
}
/**
* Receive notification of the beginning of a document.
*
* <p>
* The SAX parser will invoke this method only once, before any other methods
* in this interface or in DTDHandler (except for setDocumentLocator).
* </p>
*/
public void startDocument() throws org.xml.sax.SAXException {
// No action for the moment.
}
/**
* Receive notification of the end of a document.
*
* <p>
* The SAX parser will invoke this method only once, and it will be the last
* method invoked during the parse. The parser shall not invoke this method
* until it has either abandoned parsing (because of an unrecoverable error)
* or reached the end of input.
* </p>
*/
public void endDocument() throws org.xml.sax.SAXException {
// No action for the moment.
}
/**
* Receive notification of the beginning of an element.
*
* <p>
* The Parser will invoke this method at the beginning of every element in the
* XML document; there will be a corresponding endElement() event for every
* startElement() event (even when the element is empty). All of the element's
* content will be reported, in order, before the corresponding endElement()
* event.
* </p>
*
* <p>
* If the element name has a namespace prefix, the prefix will still be
* attached. Note that the attribute list provided will contain only
* attributes with explicit values (specified or defaulted): #IMPLIED
* attributes will be omitted.
* </p>
*
*
* @param ns
* The namespace of the node
* @param localName
* The local part of the qualified name
* @param name
* The element name.
* @param atts
* The attributes attached to the element, if any.
* @see #endElement
* @see org.xml.sax.Attributes
*/
public void startElement(String ns, String localName, String name, Attributes atts) throws org.xml.sax.SAXException {
Element elem;
// Note that the namespace-aware call must be used to correctly
// construct a Level 2 DOM, even for non-namespaced nodes.
if ((null == ns) || (ns.length() == 0))
elem = m_doc.createElementNS(null, name);
else
elem = m_doc.createElementNS(ns, name);
append(elem);
try {
int nAtts = atts.getLength();
if (0 != nAtts) {
for (int i = 0; i < nAtts; i++) {
// System.out.println("type " + atts.getType(i) + " name " +
// atts.getLocalName(i) );
// First handle a possible ID attribute
if (atts.getType(i).equalsIgnoreCase("ID"))
setIDAttribute(atts.getValue(i), elem);
String attrNS = atts.getURI(i);
if ("".equals(attrNS))
attrNS = null; // DOM represents no-namespace as null
// System.out.println("attrNS: "+attrNS+", localName:
// "+atts.getQName(i)
// +", qname: "+atts.getQName(i)+", value: "+atts.getValue(i));
// Crimson won't let us set an xmlns: attribute on the DOM.
String attrQName = atts.getQName(i);
// In SAX, xmlns[:] attributes have an empty namespace, while in DOM
// they
// should have the xmlns namespace
if (attrQName.startsWith("xmlns:") || attrQName.equals("xmlns")) {
attrNS = "http://www.w3.org/2000/xmlns/";
}
// ALWAYS use the DOM Level 2 call!
elem.setAttributeNS(attrNS, attrQName, atts.getValue(i));
}
}
if (locator!=null) {
int lineNumber = locator.getLineNumber();
elem.setAttributeNS("http://jbpm.org/line-numbers", "line-number", Integer.toString(lineNumber));
int columnNumber = locator.getColumnNumber();
elem.setAttributeNS("http://jbpm.org/line-numbers", "column-number", Integer.toString(columnNumber));
}
/*
* Adding namespace nodes to the DOM tree;
*/
int nDecls = m_prefixMappings.size();
String prefix, declURL;
for (int i = 0; i < nDecls; i += 2) {
prefix = (String) m_prefixMappings.elementAt(i);
if (prefix == null)
continue;
declURL = (String) m_prefixMappings.elementAt(i + 1);
elem.setAttributeNS("http://www.w3.org/2000/xmlns/", prefix, declURL);
}
m_prefixMappings.clear();
// append(elem);
m_elemStack.push(elem);
m_currentNode = elem;
// append(elem);
} catch (java.lang.Exception de) {
// de.printStackTrace();
throw new org.xml.sax.SAXException(de);
}
}
/**
*
*
*
* Receive notification of the end of an element.
*
* <p>
* The SAX parser will invoke this method at the end of every element in the
* XML document; there will be a corresponding startElement() event for every
* endElement() event (even when the element is empty).
* </p>
*
* <p>
* If the element name has a namespace prefix, the prefix will still be
* attached to the name.
* </p>
*
*
* @param ns
* the namespace of the element
* @param localName
* The local part of the qualified name of the element
* @param name
* The element name
*/
public void endElement(String ns, String localName, String name) throws org.xml.sax.SAXException {
m_elemStack.pop();
m_currentNode = m_elemStack.isEmpty() ? null : (Node) m_elemStack.peek();
}
/**
* Set an ID string to node association in the ID table.
*
* @param id
* The ID string.
* @param elem
* The associated ID.
*/
public void setIDAttribute(String id, Element elem) {
// Do nothing. This method is meant to be overiden.
}
/**
* Receive notification of character data.
*
* <p>
* The Parser will call this method to report each chunk of character data.
* SAX parsers may return all contiguous character data in a single chunk, or
* they may split it into several chunks; however, all of the characters in
* any single event must come from the same external entity, so that the
* Locator provides useful information.
* </p>
*
* <p>
* The application must not attempt to read from the array outside of the
* specified range.
* </p>
*
* <p>
* Note that some parsers will report whitespace using the
* ignorableWhitespace() method rather than this one (validating parsers must
* do so).
* </p>
*
* @param ch
* The characters from the XML document.
* @param start
* The start position in the array.
* @param length
* The number of characters to read from the array.
* @see #ignorableWhitespace
* @see org.xml.sax.Locator
*/
public void characters(char ch[], int start, int length) throws org.xml.sax.SAXException {
if (isOutsideDocElem() && isWhiteSpace(ch, start, length))
return; // avoid DOM006 Hierarchy request error
if (m_inCData) {
cdata(ch, start, length);
return;
}
String s = new String(ch, start, length);
Node childNode;
childNode = m_currentNode != null ? m_currentNode.getLastChild() : null;
if (childNode != null && childNode.getNodeType() == Node.TEXT_NODE) {
((Text) childNode).appendData(s);
} else {
Text text = m_doc.createTextNode(s);
append(text);
}
}
/**
* If available, when the disable-output-escaping attribute is used, output
* raw text without escaping. A PI will be inserted in front of the node with
* the name "lotusxsl-next-is-raw" and a value of "formatter-to-dom".
*
* @param ch
* Array containing the characters
* @param start
* Index to start of characters in the array
* @param length
* Number of characters in the array
*/
public void charactersRaw(char ch[], int start, int length) throws org.xml.sax.SAXException {
if (isOutsideDocElem() && isWhiteSpace(ch, start, length))
return; // avoid DOM006 Hierarchy request error
String s = new String(ch, start, length);
append(m_doc.createProcessingInstruction("xslt-next-is-raw", "formatter-to-dom"));
append(m_doc.createTextNode(s));
}
/**
* Report the beginning of an entity.
*
* The start and end of the document entity are not reported. The start and
* end of the external DTD subset are reported using the pseudo-name "[dtd]".
* All other events must be properly nested within start/end entity events.
*
* @param name
* The name of the entity. If it is a parameter entity, the name will
* begin with '%'.
* @see #endEntity
* @see org.xml.sax.ext.DeclHandler#internalEntityDecl
* @see org.xml.sax.ext.DeclHandler#externalEntityDecl
*/
public void startEntity(String name) throws org.xml.sax.SAXException {
// Almost certainly the wrong behavior...
// entityReference(name);
}
/**
* Report the end of an entity.
*
* @param name
* The name of the entity that is ending.
* @see #startEntity
*/
public void endEntity(String name) throws org.xml.sax.SAXException {
}
/**
* Receive notivication of a entityReference.
*
* @param name
* name of the entity reference
*/
public void entityReference(String name) throws org.xml.sax.SAXException {
append(m_doc.createEntityReference(name));
}
/**
* Receive notification of ignorable whitespace in element content.
*
* <p>
* Validating Parsers must use this method to report each chunk of ignorable
* whitespace (see the W3C XML 1.0 recommendation, section 2.10):
* non-validating parsers may also use this method if they are capable of
* parsing and using content models.
* </p>
*
* <p>
* SAX parsers may return all contiguous whitespace in a single chunk, or they
* may split it into several chunks; however, all of the characters in any
* single event must come from the same external entity, so that the Locator
* provides useful information.
* </p>
*
* <p>
* The application must not attempt to read from the array outside of the
* specified range.
* </p>
*
* @param ch
* The characters from the XML document.
* @param start
* The start position in the array.
* @param length
* The number of characters to read from the array.
* @see #characters
*/
public void ignorableWhitespace(char ch[], int start, int length) throws org.xml.sax.SAXException {
if (isOutsideDocElem())
return; // avoid DOM006 Hierarchy request error
String s = new String(ch, start, length);
append(m_doc.createTextNode(s));
}
/**
* Tell if the current node is outside the document element.
*
* @return true if the current node is outside the document element.
*/
private boolean isOutsideDocElem() {
return (null == m_docFrag) && m_elemStack.size() == 0 && (null == m_currentNode || m_currentNode.getNodeType() == Node.DOCUMENT_NODE);
}
/**
* Receive notification of a processing instruction.
*
* <p>
* The Parser will invoke this method once for each processing instruction
* found: note that processing instructions may occur before or after the main
* document element.
* </p>
*
* <p>
* A SAX parser should never report an XML declaration (XML 1.0, section 2.8)
* or a text declaration (XML 1.0, section 4.3.1) using this method.
* </p>
*
* @param target
* The processing instruction target.
* @param data
* The processing instruction data, or null if none was supplied.
*/
public void processingInstruction(String target, String data) throws org.xml.sax.SAXException {
append(m_doc.createProcessingInstruction(target, data));
}
/**
* Report an XML comment anywhere in the document.
*
* This callback will be used for comments inside or outside the document
* element, including comments in the external DTD subset (if read).
*
* @param ch
* An array holding the characters in the comment.
* @param start
* The starting position in the array.
* @param length
* The number of characters to use from the array.
*/
public void comment(char ch[], int start, int length) throws org.xml.sax.SAXException {
append(m_doc.createComment(new String(ch, start, length)));
}
/** Flag indicating that we are processing a CData section */
protected boolean m_inCData = false;
/**
* Report the start of a CDATA section.
*
* @see #endCDATA
*/
public void startCDATA() throws org.xml.sax.SAXException {
m_inCData = true;
append(m_doc.createCDATASection(""));
}
/**
* Report the end of a CDATA section.
*
* @see #startCDATA
*/
public void endCDATA() throws org.xml.sax.SAXException {
m_inCData = false;
}
/**
* Receive notification of cdata.
*
* <p>
* The Parser will call this method to report each chunk of character data.
* SAX parsers may return all contiguous character data in a single chunk, or
* they may split it into several chunks; however, all of the characters in
* any single event must come from the same external entity, so that the
* Locator provides useful information.
* </p>
*
* <p>
* The application must not attempt to read from the array outside of the
* specified range.
* </p>
*
* <p>
* Note that some parsers will report whitespace using the
* ignorableWhitespace() method rather than this one (validating parsers must
* do so).
* </p>
*
* @param ch
* The characters from the XML document.
* @param start
* The start position in the array.
* @param length
* The number of characters to read from the array.
* @see #ignorableWhitespace
* @see org.xml.sax.Locator
*/
public void cdata(char ch[], int start, int length) throws org.xml.sax.SAXException {
if (isOutsideDocElem() && isWhiteSpace(ch, start, length))
return; // avoid DOM006 Hierarchy request error
String s = new String(ch, start, length);
CDATASection section = (CDATASection) m_currentNode.getLastChild();
section.appendData(s);
}
/**
* Report the start of DTD declarations, if any.
*
* Any declarations are assumed to be in the internal subset unless otherwise
* indicated.
*
* @param name
* The document type name.
* @param publicId
* The declared public identifier for the external DTD subset, or
* null if none was declared.
* @param systemId
* The declared system identifier for the external DTD subset, or
* null if none was declared.
* @see #endDTD
* @see #startEntity
*/
public void startDTD(String name, String publicId, String systemId) throws org.xml.sax.SAXException {
// Do nothing for now.
}
/**
* Report the end of DTD declarations.
*
* @see #startDTD
*/
public void endDTD() throws org.xml.sax.SAXException {
// Do nothing for now.
}
/**
* Begin the scope of a prefix-URI Namespace mapping.
*
* <p>
* The information from this event is not necessary for normal Namespace
* processing: the SAX XML reader will automatically replace prefixes for
* element and attribute names when the http://xml.org/sax/features/namespaces
* feature is true (the default).
* </p>
*
* <p>
* There are cases, however, when applications need to use prefixes in
* character data or in attribute values, where they cannot safely be expanded
* automatically; the start/endPrefixMapping event supplies the information to
* the application to expand prefixes in those contexts itself, if necessary.
* </p>
*
* <p>
* Note that start/endPrefixMapping events are not guaranteed to be properly
* nested relative to each-other: all startPrefixMapping events will occur
* before the corresponding startElement event, and all endPrefixMapping
* events will occur after the corresponding endElement event, but their order
* is not guaranteed.
* </p>
*
* @param prefix
* The Namespace prefix being declared.
* @param uri
* The Namespace URI the prefix is mapped to.
* @see #endPrefixMapping
* @see #startElement
*/
public void startPrefixMapping(String prefix, String uri) throws org.xml.sax.SAXException {
if (null == prefix || prefix.equals(""))
prefix = "xmlns";
else
prefix = "xmlns:" + prefix;
m_prefixMappings.addElement(prefix);
m_prefixMappings.addElement(uri);
}
/**
* End the scope of a prefix-URI mapping.
*
* <p>
* See startPrefixMapping for details. This event will always occur after the
* corresponding endElement event, but the order of endPrefixMapping events is
* not otherwise guaranteed.
* </p>
*
* @param prefix
* The prefix that was being mapping.
* @see #startPrefixMapping
* @see #endElement
*/
public void endPrefixMapping(String prefix) throws org.xml.sax.SAXException {
}
/**
* Receive notification of a skipped entity.
*
* <p>
* The Parser will invoke this method once for each entity skipped.
* Non-validating processors may skip entities if they have not seen the
* declarations (because, for example, the entity was declared in an external
* DTD subset). All processors may skip external entities, depending on the
* values of the http://xml.org/sax/features/external-general-entities and the
* http://xml.org/sax/features/external-parameter-entities properties.
* </p>
*
* @param name
* The name of the skipped entity. If it is a parameter entity, the
* name will begin with '%'.
*/
public void skippedEntity(String name) throws org.xml.sax.SAXException {
}
/**
* Returns whether the specified <var>ch</var> conforms to the XML 1.0
* definition of whitespace. Refer to <A
* href="http://www.w3.org/TR/1998/REC-xml-19980210#NT-S"> the definition of
* <CODE>S</CODE></A> for details.
*
* @param ch
* Character to check as XML whitespace.
* @return =true if <var>ch</var> is XML whitespace; otherwise =false.
*/
public static boolean isWhiteSpace(char ch) {
return (ch == 0x20) || (ch == 0x09) || (ch == 0xD) || (ch == 0xA);
}
/**
* Tell if the string is whitespace.
*
* @param ch
* Character array to check as XML whitespace.
* @param start
* Start index of characters in the array
* @param length
* Number of characters in the array
* @return True if the characters in the array are XML whitespace; otherwise,
* false.
*/
public static boolean isWhiteSpace(char ch[], int start, int length) {
int end = start + length;
for (int s = start; s < end; s++) {
if (!isWhiteSpace(ch[s]))
return false;
}
return true;
}
}