/*
* 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.
*/
package org.apache.cocoon.xml;
import java.util.Iterator;
import java.util.Map;
import java.io.Writer;
import java.io.IOException;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.Attributes;
/**
* Modification of the SAX buffer with parameterization capabilities.
*
* Any <code>{name}</code> expression inside of the character events can be
* replaced by the content of another SaxBuffer if it is present in the map
* passed to the {@link #toSAX(ContentHandler, Map)} method.
*
* @author <a href="mailto:vgritsenko@apache.org">Vadim Gritsenko</a>
* @version CVS $Id$
*/
public class ParamSaxBuffer extends SaxBuffer {
/**
* If ch (in characters()) contains an unmatched '{' then
* we save the chars from '{' onward in previous_ch.
* Next call to characters() prepends the saved chars to ch before processing
* (and sets previous_ch to null).
*/
private char[] previous_ch = null;
/**
* Creates empty SaxBuffer
*/
public ParamSaxBuffer() {
}
/**
* Creates copy of another SaxBuffer
*/
public ParamSaxBuffer(SaxBuffer saxBuffer) {
super(saxBuffer);
}
/**
* Parses text and extracts <code>{name}</code> parameters for later
* substitution.
* '{' is escaped with a preceding '\'.
*/
public void characters(char ch[], int start, int length) throws SAXException {
if (previous_ch != null) {
// prepend char's from previous_ch to ch
char[] buf = new char[length + previous_ch.length];
System.arraycopy(previous_ch, 0, buf, 0, previous_ch.length);
System.arraycopy(ch, start, buf, previous_ch.length, length);
ch = buf;
start = 0;
length += previous_ch.length;
previous_ch = null;
}
final int end = start + length;
for (int i = start; i < end; i++) {
if (ch[i] == '\\') {
if (i + 1 == end) {
// if '\' is the last char, flush chars and let's wait to see if a '{' or '\' will come next
addBit(new Characters(ch, start, i - start));
previous_ch = new char[]{ch[i]};
return;
}
if (ch[i + 1] == '{' || ch[i + 1] == '\\') {
// Encountered "\{" or "\\", meaning that the next char should be escaped
addBit(new Characters(ch, start, i - start));
addBit(new Characters(new char[]{ch[i + 1]}, 0, 1));
i++;
start = i + 1;
continue;
}
}
else if (ch[i] == '{') {
// Send any collected characters so far
if (i > start) {
addBit(new Characters(ch, start, i - start));
}
// Find closing brace, and construct parameter name
StringBuffer name = new StringBuffer();
int j = i + 1;
for (; j < end; j++) {
if (ch[j] == '}') {
break;
}
name.append(ch[j]);
}
if (j == end) {
// '{' without a closing '}'
// save char's from '{' in previous_ch in case the following call to characters()
// provides the '}'
previous_ch = new char[end - i];
System.arraycopy(ch, i, previous_ch, 0, end - i);
return;
}
addBit(new Parameter(name.toString()));
// Continue processing
i = j;
start = j + 1;
continue;
}
}
// Send any tailing characters
if (start < end) {
addBit(new Characters(ch, start, end - start));
}
}
public void endElement(String namespaceURI, String localName, String qName) throws SAXException {
flushChars();
super.endElement(namespaceURI, localName, qName);
}
public void ignorableWhitespace(char ch[], int start, int length) throws SAXException {
flushChars();
super.ignorableWhitespace(ch, start, length);
}
public void processingInstruction(String target, String data) throws SAXException {
flushChars();
super.processingInstruction(target, data);
}
public void startDocument() throws SAXException {
flushChars();
super.startDocument();
}
public void startElement(String namespaceURI, String localName, String qName, Attributes atts) throws SAXException {
flushChars();
super.startElement(namespaceURI, localName, qName, atts);
}
public void endDocument() throws SAXException {
flushChars();
super.endDocument();
}
public void comment(char ch[], int start, int length) throws SAXException {
flushChars();
super.comment(ch, start, length);
}
public void endDTD() throws SAXException {
flushChars();
super.endDTD();
}
public void startDTD(String name, String publicId, String systemId) throws SAXException {
flushChars();
super.startDTD(name, publicId, systemId);
}
private void flushChars() {
// Handle saved chars (in case we had a '{' with no matching '}').
if (previous_ch != null) {
addBit(new Characters(previous_ch, 0, previous_ch.length));
previous_ch = null;
}
}
/**
* @param parameters map containing SaxBuffers
*/
public void toSAX(ContentHandler contentHandler, Map parameters) throws SAXException {
for (Iterator i = bits(); i.hasNext();) {
SaxBit saxbit = (SaxBit)i.next();
if (saxbit instanceof Parameter) {
((Parameter)saxbit).send(contentHandler, parameters);
} else {
saxbit.send(contentHandler);
}
}
}
/**
* @param parameters map containing SaxBuffers
*/
public String toString(Map parameters) throws SAXException {
final StringBuffer buffer = new StringBuffer();
for (Iterator i = bits(); i.hasNext();) {
SaxBit saxbit = (SaxBit)i.next();
if (saxbit instanceof Parameter) {
((Parameter)saxbit).toString(buffer, parameters);
} else if (saxbit instanceof Characters) {
((Characters) saxbit).toString(buffer);
}
}
return buffer.toString();
}
final static class Parameter implements SaxBit {
private final String name;
public Parameter(String name) {
this.name = name;
}
public void send(ContentHandler contentHandler) {
}
public void send(ContentHandler contentHandler, Map parameters) throws SAXException {
SaxBuffer value = (SaxBuffer)parameters.get(name);
if (value != null) {
value.toSAX(contentHandler);
}
}
public void toString(StringBuffer result, Map parameters) throws SAXException {
String value = (String)parameters.get(name);
if (value != null) {
result.append(value);
}
}
public void dump(Writer writer) throws IOException {
writer.write("[Parameter] name=" + name);
}
}
}