/*
* 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.myfaces.trinidad.change;
import java.util.Map;
import javax.el.ValueExpression;
import javax.faces.component.ContextCallback;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.el.ValueBinding;
import org.apache.myfaces.trinidad.logging.TrinidadLogger;
import org.apache.myfaces.trinidad.model.RowKeySet;
/**
* Handles RowKeySetAttribute changes, which need to be handled specially because they are mutable
* and programmers assume that the instances don't change.
*
* Cases that we need to worry about:
* 1) old value is null
* 2) new value is null (should clear existing RowKeySet if possible)
* 3) old value = new value
* 4) new value is a ValueExpression or ValueBinding
* 5) old value is a ValueExpression that needs to be evaluated in context
* 6) RowKeySet is internally bound to a model that needs to be evaluated in context
*/
public final class RowKeySetAttributeChange extends AttributeComponentChange
{
public RowKeySetAttributeChange(String clientId, String propertyName, Object value)
{
super(propertyName, value);
if ((clientId == null) || (clientId.length() == 0))
throw new IllegalArgumentException("No clientId specified");
_clientId = clientId;
}
@Override
@SuppressWarnings("deprecation")
public void changeComponent(UIComponent component)
{
Map<String, Object> attributeMap = component.getAttributes();
Object newAttributeValue = getAttributeValue();
String attrName = getAttributeName();
if ((newAttributeValue instanceof RowKeySet) || (newAttributeValue == null))
{
// Specially handle RowKeySet case by replacing the contents of the RowKeySet in-place
// rather than replacing the entire object. This keeps the mutable object instance from
// changing
_updateRowKeySetInPlace(component, attrName, (RowKeySet)newAttributeValue);
}
else if (newAttributeValue instanceof ValueExpression)
{
// if the new attribute value is a ValueExpession, set it and remove the old value
// so that the ValueExpression takes precedence
component.setValueExpression(attrName, (ValueExpression)newAttributeValue);
attributeMap.remove(attrName);
}
else if (newAttributeValue instanceof ValueBinding)
{
// if the new attribute value is a ValueBinding, set it and remove the old value
// so that the ValueBinding takes precedence
component.setValueBinding(attrName, (ValueBinding)newAttributeValue);
attributeMap.remove(attrName);
}
else
{
// perform the default behavior
attributeMap.put(attrName, newAttributeValue);
}
}
private void _updateRowKeySetInPlace(UIComponent component, String attrName, RowKeySet newValue)
{
ValueExpression oldExpression = component.getValueExpression(attrName);
// due to bug in how the trinidad table and tree handle their RowKeySets, always use
// invoke on component and get the old value in context all of the time for now rather
// than trying to get the value directly if we don't have an expression
//use EL to get the oldValue and then determine whether we need to update in place
final FacesContext context = FacesContext.getCurrentInstance();
context.getViewRoot().invokeOnComponent(
context,
_clientId,
new GetOldValueAndUpdate(oldExpression, attrName, newValue));
}
/**
* Get the oldValue in context and update it in context
*/
private static final class GetOldValueAndUpdate implements ContextCallback
{
public GetOldValueAndUpdate(ValueExpression expression, String attributeName, RowKeySet newKeySet)
{
_expression = expression;
_attributeName = attributeName;
_newKeySet = newKeySet;
}
public void invokeContextCallback(FacesContext context,
UIComponent target)
{
Object oldValue;
// due to bug in how tables and trees handle RowKeySet, temporarily support getting the
// old value in context, even when we don't have a value expression
if (_expression != null)
oldValue = _expression.getValue(context.getELContext());
else
oldValue = target.getAttributes().get(_attributeName);
// update the old KeySet with the old and new values
_updateKeySet(target, oldValue);
}
private void _updateKeySet(UIComponent component, Object oldValue)
{
// check for equality because otherwise we would clear ourselves and end up empty
if (oldValue != _newKeySet)
{
// if the old value is a RowKeySet, we can replace in place
if (oldValue instanceof RowKeySet)
{
RowKeySet oldKeySet = (RowKeySet)oldValue;
try
{
oldKeySet.clear();
if (_newKeySet != null)
{
oldKeySet.addAll(_newKeySet);
}
}
catch (Exception e)
{
_LOG.warning("FAILED_ROWKEYSETATTRIBUTECHANGE", e);
return;
}
}
else
{
// if the oldKeySet is null, just set the new keySet
component.getAttributes().put(_attributeName, _newKeySet);
}
}
}
private final ValueExpression _expression;
private final String _attributeName;
private final RowKeySet _newKeySet;
}
private static final long serialVersionUID = 1L;
static private final TrinidadLogger _LOG = TrinidadLogger.createTrinidadLogger(RowKeySetAttributeChange.class);
private final String _clientId;
}