001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.pageload;
016    
017    import java.util.Iterator;
018    
019    import org.apache.hivemind.ApplicationRuntimeException;
020    import org.apache.tapestry.IComponent;
021    import org.apache.tapestry.spec.IComponentSpecification;
022    import org.apache.tapestry.spec.IParameterSpecification;
023    
024    /**
025     * Verify whether all required parameters in the examined component are bound, and if they are not,
026     * throw an exception.
027     * 
028     * @author mindbridge
029     * @since 3.0
030     */
031    public class VerifyRequiredParametersVisitor implements IComponentVisitor
032    {
033        /**
034         * @see org.apache.tapestry.pageload.IComponentVisitor#visitComponent(org.apache.tapestry.IComponent)
035         */
036        public void visitComponent(IComponent component)
037        {
038            IComponentSpecification spec = component.getSpecification();
039    
040            Iterator i = spec.getRequiredParameters().iterator();
041    
042            while (i.hasNext())
043            {
044                IParameterSpecification parameterSpec = (IParameterSpecification) i.next();
045    
046                String name = parameterSpec.getParameterName();
047    
048                if (component.getBinding(name) == null)
049                    throw new ApplicationRuntimeException(PageloadMessages.requiredParameterNotBound(
050                            name,
051                            component), component, component.getLocation(), null);
052            }
053        }
054    
055    }