// Copyright 2004, 2005 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.tapestry.pageload;
import java.util.Iterator;
import org.apache.hivemind.ApplicationRuntimeException;
import org.apache.tapestry.IBinding;
import org.apache.tapestry.IComponent;
import org.apache.tapestry.binding.BindingConstants;
import org.apache.tapestry.binding.BindingSource;
import org.apache.tapestry.spec.IComponentSpecification;
import org.apache.tapestry.spec.IParameterSpecification;
/**
* For all parameters in the examined component that have default values, but are not bound,
* automatically add an ExpressionBinding with the default value.
*
* @author mindbridge
* @since 3.0
*/
public class EstablishDefaultParameterValuesVisitor implements IComponentVisitor
{
/** @since 4.0 */
private BindingSource _bindingSource;
/**
* @see org.apache.tapestry.pageload.IComponentVisitor#visitComponent(org.apache.tapestry.IComponent)
*/
public void visitComponent(IComponent component)
{
IComponentSpecification spec = component.getSpecification();
Iterator i = spec.getParameterNames().iterator();
while (i.hasNext())
{
String name = (String) i.next();
IParameterSpecification parameterSpec = spec.getParameter(name);
String defaultValue = parameterSpec.getDefaultValue();
if (defaultValue == null)
continue;
// the parameter has a default value, so it must not be required
if (parameterSpec.isRequired())
throw new ApplicationRuntimeException(PageloadMessages
.parameterMustHaveNoDefaultValue(component, name), component, parameterSpec
.getLocation(), null);
// if there is no binding for this parameter, bind it to the default value.
// In 3.0, default-value as always an OGNL expression, but now its a locator.
if (component.getBinding(name) == null)
{
String description = PageloadMessages.defaultParameterName(name);
String defaultBindingType = parameterSpec.getDefaultBindingType();
if (defaultBindingType == null)
defaultBindingType = BindingConstants.OGNL_PREFIX;
IBinding binding = _bindingSource.createBinding(
component,
description,
defaultValue,
defaultBindingType,
parameterSpec.getLocation());
component.setBinding(name, binding);
}
}
}
/** @since 4.0 */
public void setBindingSource(BindingSource bindingSource)
{
_bindingSource = bindingSource;
}
}