| // Copyright 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.tapestry.pageload; |
| |
| import java.util.Iterator; |
| |
| import org.apache.tapestry.ApplicationRuntimeException; |
| import org.apache.tapestry.IBinding; |
| import org.apache.tapestry.IComponent; |
| import org.apache.tapestry.IResourceResolver; |
| import org.apache.tapestry.Tapestry; |
| import org.apache.tapestry.binding.ExpressionBinding; |
| 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 |
| * @version $Id$ |
| * @since 3.0 |
| */ |
| public class EstablishDefaultParameterValuesVisitor implements IComponentVisitor |
| { |
| private IResourceResolver _resolver; |
| |
| public EstablishDefaultParameterValuesVisitor(IResourceResolver resolver) |
| { |
| _resolver = resolver; |
| } |
| |
| /** |
| * @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( |
| Tapestry.format( |
| "EstablishDefaultParameterValuesVisitor.parameter-must-have-no-default-value", |
| component.getExtendedId(), |
| name), |
| component, |
| parameterSpec.getLocation(), |
| null); |
| |
| // if there is no binding for this parameter, bind it to the default value |
| if (component.getBinding(name) == null) { |
| IBinding binding = new ExpressionBinding(_resolver, component, defaultValue, parameterSpec.getLocation()); |
| component.setBinding(name, binding); |
| } |
| |
| } |
| } |
| |
| } |