/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed 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.util.Iterator;
import java.util.Locale;
import org.apache.avalon.framework.context.Context;
import org.apache.cocoon.components.ContextHelper;
import org.apache.cocoon.components.flow.FlowHelper;
import org.apache.cocoon.forms.Constants;
import org.apache.cocoon.xml.AttributesImpl;
import org.apache.cocoon.xml.XMLUtils;
import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.Pointer;
import org.apache.excalibur.xml.sax.XMLizable;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
/**
* A selection list that takes its values from the flow page data.
*
* @see org.apache.cocoon.forms.datatype.FlowJXPathSelectionListBuilder
* @author <a href="http://www.apache.org/~sylvain/">Sylvain Wallez</a>
* @version CVS $Id: FlowJXPathSelectionList.java,v 1.4 2004/03/09 13:17:26 cziegeler Exp $
*/
public class FlowJXPathSelectionList implements SelectionList {
private Context context;
private String listPath;
private String valuePath;
private String labelPath;
private Datatype datatype;
private Object model;
public FlowJXPathSelectionList(Context context, String listPath, String valuePath, String labelPath, Datatype datatype) {
this.context = context;
this.listPath = listPath;
this.valuePath = valuePath;
this.labelPath = labelPath;
this.datatype = datatype;
}
/**
* Builds a dynamic selection list from an in-memory collection.
* @see org.apache.cocoon.forms.formmodel.Field#setSelectionList(Object model, String valuePath, String labelPath)
* @param model The collection used as a model for the selection list.
* @param valuePath An XPath expression referring to the attribute used
* to populate the values of the list's items.
* @param labelPath An XPath expression referring to the attribute used
* to populate the labels of the list's items.
* @param datatype
*/
public FlowJXPathSelectionList(Object model, String valuePath, String labelPath, Datatype datatype) {
this.model = model;
this.valuePath = valuePath;
this.labelPath = labelPath;
this.datatype = datatype;
}
public Datatype getDatatype() {
return this.datatype;
}
public void generateSaxFragment(ContentHandler contentHandler, Locale locale) throws SAXException {
JXPathContext ctx = null;
Iterator iter = null;
if (model == null) {
Object flowData = FlowHelper.getContextObject(ContextHelper.getObjectModel(this.context));
if (flowData == null) {
throw new SAXException("No flow data to produce selection list");
}
// Move to the list location
ctx = JXPathContext.newContext(flowData);
// Iterate on all elements of the list
iter = ctx.iteratePointers(this.listPath);
} else {
// Move to the list location
ctx = JXPathContext.newContext(model);
// Iterate on all elements of the list
iter = ctx.iteratePointers(".");
}
// Start the selection-list
contentHandler.startElement(Constants.INSTANCE_NS, SELECTION_LIST_EL, Constants.INSTANCE_PREFIX_COLON + SELECTION_LIST_EL, XMLUtils.EMPTY_ATTRIBUTES);
while(iter.hasNext()) {
String stringValue = "";
Object label = null;
// Get a context on the current item
Pointer ptr = (Pointer)iter.next();
if (ptr.getValue() != null) {
JXPathContext itemCtx = ctx.getRelativeContext(ptr);
// Get the value as a string
Object value = itemCtx.getValue(this.valuePath);
// List may contain null value, and (per contract with convertors),
// convertors are not invoked on nulls.
if (value != null) {
stringValue = this.datatype.convertToString(value, locale);
}
// Get the label (can be ommitted)
itemCtx.setLenient(true);
label = itemCtx.getValue(this.labelPath);
if (label == null) {
label = stringValue;
}
}
// Output this item
AttributesImpl itemAttrs = new AttributesImpl();
itemAttrs.addCDATAAttribute("value", stringValue);
contentHandler.startElement(Constants.INSTANCE_NS, ITEM_EL, Constants.INSTANCE_PREFIX_COLON + ITEM_EL, itemAttrs);
if (label != null) {
contentHandler.startElement(Constants.INSTANCE_NS, LABEL_EL, Constants.INSTANCE_PREFIX_COLON + LABEL_EL, XMLUtils.EMPTY_ATTRIBUTES);
if (label instanceof XMLizable) {
((XMLizable)label).toSAX(contentHandler);
} else {
String stringLabel = label.toString();
contentHandler.characters(stringLabel.toCharArray(), 0, stringLabel.length());
}
contentHandler.endElement(Constants.INSTANCE_NS, LABEL_EL, Constants.INSTANCE_PREFIX_COLON + LABEL_EL);
}
contentHandler.endElement(Constants.INSTANCE_NS, ITEM_EL, Constants.INSTANCE_PREFIX_COLON + ITEM_EL);
}
// End the selection-list
contentHandler.endElement(Constants.INSTANCE_NS, SELECTION_LIST_EL, Constants.INSTANCE_PREFIX_COLON + SELECTION_LIST_EL);
}
}