/*
* 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.binding;
import java.util.Locale;
import org.apache.avalon.framework.logger.Logger;
import org.apache.cocoon.forms.datatype.convertor.Convertor;
import org.apache.cocoon.forms.datatype.convertor.ConversionResult;
import org.apache.cocoon.forms.formmodel.Widget;
import org.apache.commons.jxpath.JXPathContext;
import org.apache.commons.jxpath.JXPathException;
/**
* ValueJXPathBinding provides an implementation of a {@link Binding}
* that loads and saves the information behind a specific xpath expresion
* (pointing to an attribute or text-node) to and from a specific CForms
* widget as identified by its id.
*
* @version CVS $Id: ValueJXPathBinding.java,v 1.7 2004/05/11 08:22:54 bruno Exp $
*/
public class ValueJXPathBinding extends JXPathBindingBase {
/**
* The xpath expression to the objectModel property
*/
private final String xpath;
/**
* The id of the CForms form-widget
*/
private final String fieldId;
/**
* Flag indicating if the objectModel-property can be altered or not
*/
private final JXPathBindingBase updateBinding;
/**
* Optional convertor to convert values to and from strings when setting or reading
* the from the model. Especially used in combination with XML models where everything
* are strings.
*/
private final Convertor convertor;
/**
* The locale to pass to the {@link #convertor}.
*/
private final Locale convertorLocale;
/**
* Constructs FieldJXPathBinding.
*
* @param convertor may be null
*/
public ValueJXPathBinding(JXPathBindingBuilderBase.CommonAttributes commonAtts, String widgetId, String xpath, JXPathBindingBase[] updateBindings,
Convertor convertor, Locale convertorLocale) {
super(commonAtts);
this.fieldId = widgetId;
this.xpath = xpath;
this.updateBinding = new ComposedJXPathBindingBase(JXPathBindingBuilderBase.CommonAttributes.DEFAULT, updateBindings);
this.convertor = convertor;
this.convertorLocale = convertorLocale;
}
/**
* Actively performs the binding from the ObjectModel wrapped in a jxpath
* context to the CForms-form-widget specified in this object.
*/
public void doLoad(Widget frmModel, JXPathContext jxpc) throws BindingException {
Widget widget = selectWidget(frmModel, this.fieldId);
if (widget == null) {
throw new BindingException("The widget with the ID [" + this.fieldId
+ "] referenced in the binding does not exist in the form definition.");
}
Object value = jxpc.getValue(this.xpath);
if (value != null && convertor != null) {
if (value instanceof String) {
ConversionResult conversionResult = convertor.convertFromString((String)value, convertorLocale, null);
if (conversionResult.isSuccessful())
value = conversionResult.getResult();
else
value = null;
} else {
getLogger().warn("Convertor ignored on backend-value which isn't of type String.");
}
}
widget.setValue(value);
if (getLogger().isDebugEnabled()) {
getLogger().debug("Done loading " + toString() + " -- value= " + value);
}
}
/**
* Actively performs the binding from the CForms-form to the ObjectModel
* wrapped in a jxpath context
*/
public void doSave(Widget frmModel, JXPathContext jxpc) throws BindingException {
Widget widget = selectWidget(frmModel, this.fieldId);
Object value = widget.getValue();
if (value != null && convertor != null) {
value = convertor.convertToString(value, convertorLocale, null);
}
Object oldValue = jxpc.getValue(this.xpath);
if (getLogger().isDebugEnabled()) {
getLogger().debug("value= " + value + "-- oldvalue=" + oldValue);
}
boolean update = false;
if ((value == null && oldValue != null) || value != null && !value.equals(oldValue)) {
// first update the value itself
jxpc.createPathAndSetValue(this.xpath, value);
// now perform any other bindings that need to be performed when the value is updated
JXPathContext subContext = null;
try {
subContext = jxpc.getRelativeContext(jxpc.getPointer(this.xpath));
} catch (JXPathException e) {
// if the value has been set to null and the underlying model is a bean, then
// JXPath will not be able to create a relative context
if (getLogger().isDebugEnabled()) {
getLogger().debug("(Ignorable) problem binding field " + widget.getRequestParameterName(), e);
}
}
if (subContext != null) {
this.updateBinding.saveFormToModel(frmModel, subContext);
}
update = true;
}
if (getLogger().isDebugEnabled()) {
getLogger().debug("done saving " + toString() + " -- value= " + value + " -- on-update == " + update);
}
}
public String toString() {
return "ValueJXPathBinding [widget=" + this.fieldId + ", xpath=" + this.xpath + "]";
}
public void enableLogging(Logger logger) {
super.enableLogging(logger);
this.updateBinding.enableLogging(logger);
}
public String getFieldId() {
return this.fieldId;
}
public String getXPath() {
return this.xpath;
}
public Convertor getConvertor() {
return this.convertor;
}
public Locale getConvertorLocale() {
return this.convertorLocale;
}
}