/*
* 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.forms.datatype;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.Locale;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.components.ContextHelper;
import org.apache.cocoon.components.source.SourceUtil;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.forms.FormsConstants;
import org.apache.cocoon.forms.datatype.convertor.ConversionResult;
import org.apache.cocoon.forms.datatype.convertor.Convertor;
import org.apache.cocoon.forms.datatype.convertor.DefaultFormatCache;
import org.apache.cocoon.util.NetUtils;
import org.apache.cocoon.xml.AbstractXMLPipe;
import org.apache.cocoon.xml.AttributesImpl;
import org.apache.cocoon.xml.SaxBuffer;
import org.apache.cocoon.xml.XMLUtils;
import org.apache.cocoon.xml.dom.DOMBuilder;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceResolver;
import org.w3c.dom.Element;
import org.xml.sax.Attributes;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
/**
* SelectionList implementation that always reads its content from the source
* each time it is requested.
* <p>
* This list is filterable, and if a filter is provided, the "filter" parameter
* is appended to the URL, e.g. <code><fd:selection-list src="cocoon://pipeline.xml"/></code>
* will call, given the "<code>foo</code>" filter value, the URL <code>cocoon://pipeline.xml?filter=foo</code>.
* <p>
* Note: the class {@link SelectionListBuilder} also interprets the same
* <code>fd:selection-list</code> XML, so if anything changes here to how that
* XML is interpreted, it also needs to change over there and vice versa.</p>
*
* @version $Id$
*/
public class DynamicSelectionList implements FilterableSelectionList {
private String src;
private boolean usePerRequestCache;
private Datatype datatype;
private ServiceManager serviceManager;
private Context context;
/**
* @param datatype
* @param src
* @param usePerRequestCache
* @param serviceManager
* @param context
*/
public DynamicSelectionList(Datatype datatype, String src, boolean usePerRequestCache, ServiceManager serviceManager, Context context) {
this.datatype = datatype;
this.src = src;
this.serviceManager = serviceManager;
this.usePerRequestCache = usePerRequestCache;
this.context = context;
}
/**
* Creates a DynamicSelectionList without caching
* @param datatype -
* @param src -
* @param serviceManager -
*/
public DynamicSelectionList(Datatype datatype, String src, ServiceManager serviceManager) {
this.usePerRequestCache = false;
this.context = null;
this.datatype = datatype;
this.src = src;
this.serviceManager = serviceManager;
}
public Datatype getDatatype() {
return datatype;
}
/*
* This method is only used by a test case and by the public version
* of generateSaxFragment.
*/
void generateSaxFragment(ContentHandler contentHandler, Locale locale, Source source)
throws ProcessingException, SAXException, IOException {
SelectionListHandler handler = new SelectionListHandler(locale);
handler.setContentHandler(contentHandler);
SourceUtil.toSAX(serviceManager, source, null, handler);
}
/*
* This method generate SaxFragment directly from source.
*/
private void generateSaxFragmentFromSrc(String url, ContentHandler contentHandler, Locale locale) throws SAXException {
SourceResolver sourceResolver = null;
Source source = null;
try {
sourceResolver = (SourceResolver)serviceManager.lookup(SourceResolver.ROLE);
source = sourceResolver.resolveURI(url);
generateSaxFragment(contentHandler, locale, source);
} catch (SAXException e) {
throw e;
} catch (Exception e) {
throw new SAXException("Error while generating selection list: " + e.getMessage(), e);
} finally {
if (sourceResolver != null) {
if (source != null) {
try { sourceResolver.release(source); } catch (Exception e) {}
}
serviceManager.release(sourceResolver);
}
}
}
public void generateSaxFragment(ContentHandler contentHandler, Locale locale, String filter) throws SAXException {
String url = this.src;
if (filter != null) {
if (url.indexOf('?') != -1) {
try {
url += "&filter=" + NetUtils.encode(filter, "utf-8");
} catch (UnsupportedEncodingException ignore) {
// utf-8 is always supported
}
} else {
try {
url += "?filter=" + NetUtils.encode(filter, "utf-8");
} catch (UnsupportedEncodingException ignore) {
// utf-8 is always supported
}
}
}
if (usePerRequestCache) {
// Search the sax buffer in request attributes
Request request = ContextHelper.getRequest(this.context);
String attributeName = "DynamicSelectionListCache/" + url;
SaxBuffer saxBuffer = (SaxBuffer)request.getAttribute(attributeName);
if (saxBuffer == null) {
// Not found: generate the list and store it
saxBuffer = new SaxBuffer();
generateSaxFragmentFromSrc(url, saxBuffer, locale);
request.setAttribute(attributeName, saxBuffer);
}
// Output the stored saxBuffer to the contentHandler
saxBuffer.toSAX(contentHandler);
} else { // We don't use usePerRequestCache => re-read from the source.
generateSaxFragmentFromSrc(url, contentHandler, locale);
}
}
public void generateSaxFragment(ContentHandler contentHandler, Locale locale) throws SAXException {
// Generate with no filter
generateSaxFragment(contentHandler, locale, (String)null);
}
/**
* XMLConsumer used to handle selection lists generated on the fly.
*/
public class SelectionListHandler extends AbstractXMLPipe {
private Object currentValue;
private String currentValueAsString;
private boolean hasLabel;
private Locale locale;
/** The convertor used to parse the values in the selection list. */
private Convertor convertor;
private DOMBuilder convertorConfigDOMBuilder;
private int convertorConfigNestingLevel = 0;
private Convertor.FormatCache fromFormatCache = new DefaultFormatCache();
private Convertor.FormatCache toFormatCache = new DefaultFormatCache();
public SelectionListHandler(Locale locale) {
this.locale = locale;
}
public void startDocument()
throws SAXException {
}
public void endDocument()
throws SAXException {
}
public void endDTD()
throws SAXException {
}
public void startDTD(String name, String publicId, String systemId)
throws SAXException {
}
public void startElement(String namespaceURI, String localName, String qName, Attributes attributes)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigNestingLevel++;
convertorConfigDOMBuilder.startElement(namespaceURI, localName, qName, attributes);
} else if (namespaceURI.equals(FormsConstants.DEFINITION_NS)) {
if (localName.equals("item")) {
if (convertor == null) {
// if no convertor was explicitely configured, use the default one of the datatype
convertor = getDatatype().getConvertor();
}
hasLabel = false;
String unparsedValue = attributes.getValue("value");
if (unparsedValue == null || "".equals(unparsedValue)) {
// Empty (or null) value translates into the empty string
currentValueAsString = "";
} else {
ConversionResult conversionResult = convertor.convertFromString(unparsedValue, locale, fromFormatCache);
if (!conversionResult.isSuccessful()) {
throw new SAXException("Could not interpret the following value: \"" + unparsedValue + "\".");
}
currentValue = conversionResult.getResult();
currentValueAsString = getDatatype().getConvertor().convertToString(currentValue, locale, toFormatCache);
}
AttributesImpl attrs = new AttributesImpl();
attrs.addCDATAAttribute("value", currentValueAsString);
super.startElement(FormsConstants.INSTANCE_NS, localName, FormsConstants.INSTANCE_PREFIX_COLON + localName, attrs);
} else if (localName.equals("label")) {
hasLabel = true;
super.startElement(FormsConstants.INSTANCE_NS, localName, FormsConstants.INSTANCE_PREFIX_COLON + localName, attributes);
} else if (localName.equals("selection-list")) {
super.startElement(FormsConstants.INSTANCE_NS, localName, FormsConstants.INSTANCE_PREFIX_COLON + localName, attributes);
} else if (convertor == null && localName.equals("convertor")) {
// record the content of this element in a dom-tree
convertorConfigDOMBuilder = new DOMBuilder();
convertorConfigDOMBuilder.startElement(namespaceURI, localName, qName, attributes);
convertorConfigNestingLevel++;
} else {
super.startElement(namespaceURI, localName, qName, attributes);
}
} else {
super.startElement(namespaceURI, localName, qName, attributes);
}
}
private static final String LABEL_EL = "label";
public void endElement(String namespaceURI, String localName, String qName)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigNestingLevel--;
convertorConfigDOMBuilder.endElement(namespaceURI, localName, qName);
if (convertorConfigNestingLevel == 0) {
Element convertorElement = convertorConfigDOMBuilder.getDocument().getDocumentElement();
try {
convertor = getDatatype().getBuilder().buildConvertor(convertorElement);
} catch (Exception e) {
throw new SAXException("Error building convertor from convertor configuration embedded in selection list XML.", e);
}
}
} else if (namespaceURI.equals(FormsConstants.DEFINITION_NS)) {
if (localName.equals("item")) {
if (!hasLabel) {
// make the label now
super.startElement(FormsConstants.INSTANCE_NS, LABEL_EL, FormsConstants.INSTANCE_PREFIX_COLON + LABEL_EL, XMLUtils.EMPTY_ATTRIBUTES);
super.characters(currentValueAsString.toCharArray(), 0, currentValueAsString.length());
super.endElement(FormsConstants.INSTANCE_NS, LABEL_EL, FormsConstants.INSTANCE_PREFIX_COLON + LABEL_EL);
}
super.endElement(FormsConstants.INSTANCE_NS, localName, FormsConstants.INSTANCE_PREFIX_COLON + localName);
} else if (localName.equals("label")) {
super.endElement(FormsConstants.INSTANCE_NS, localName, FormsConstants.INSTANCE_PREFIX_COLON + localName);
} else if (localName.equals("selection-list")) {
super.endElement(FormsConstants.INSTANCE_NS, localName, FormsConstants.INSTANCE_PREFIX_COLON + localName);
} else {
super.endElement(namespaceURI, localName, qName);
}
} else {
super.endElement(namespaceURI, localName, qName);
}
}
public void comment(char ch[], int start, int len)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.comment(ch, start, len);
} else
super.comment(ch, start, len);
}
public void startPrefixMapping(String prefix, String uri)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.startPrefixMapping(prefix, uri);
} else
super.startPrefixMapping(prefix, uri);
}
public void endPrefixMapping(String prefix)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.endPrefixMapping(prefix);
} else
super.endPrefixMapping(prefix);
}
public void characters(char c[], int start, int len)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.characters(c, start, len);
} else
super.characters(c, start, len);
}
public void ignorableWhitespace(char c[], int start, int len)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.ignorableWhitespace(c, start, len);
} else
super.ignorableWhitespace(c, start, len);
}
public void processingInstruction(String target, String data)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.processingInstruction(target, data);
} else
super.processingInstruction(target, data);
}
public void skippedEntity(String name)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.skippedEntity(name);
} else
super.skippedEntity(name);
}
public void startEntity(String name)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.startEntity(name);
} else
super.startEntity(name);
}
public void endEntity(String name)
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.endEntity(name);
} else
super.endEntity(name);
}
public void startCDATA()
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.startCDATA();
} else
super.startCDATA();
}
public void endCDATA()
throws SAXException {
if (convertorConfigNestingLevel > 0) {
convertorConfigDOMBuilder.endCDATA();
} else
super.endCDATA();
}
}
}