001    // Copyright 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.wml;
016    
017    import org.apache.hivemind.HiveMind;
018    import org.apache.tapestry.IForm;
019    import org.apache.tapestry.IMarkupWriter;
020    import org.apache.tapestry.IRequestCycle;
021    import org.apache.tapestry.form.FormEventType;
022    import org.apache.tapestry.form.FormSupportImpl;
023    
024    /**
025     * Subclass of {@link org.apache.tapestry.form.FormSupportImpl} that
026     * adjusts the output markup to conform to WML.
027     * 
028     * @author Howard M. Lewis Ship
029     * @since 4.0
030     */
031    public class GoFormSupportImpl extends FormSupportImpl
032    {
033        public GoFormSupportImpl(IMarkupWriter writer, IRequestCycle cycle, IForm form)
034        {
035            super(writer, cycle, form);
036        }
037    
038        protected void writeTag(IMarkupWriter writer, String method, String url)
039        {
040            writer.begin("go");
041            writer.attribute("method", method);
042            writer.attribute("href", url);
043        }
044    
045        protected void writeHiddenFields()
046        {
047            // The super-implementation writes a <div> tag that's not
048            // valid as WML.
049            
050            writeHiddenFieldList(getHiddenFieldWriter());
051        }
052        
053        protected void writeHiddenField(IMarkupWriter writer, String name,
054                String id, String value)
055        {
056            writer.beginEmpty("postfield");
057            writer.attribute("name", name);
058    
059            if (HiveMind.isNonBlank(id)) writer.attribute("id", id);
060    
061            writer.attribute("value", value);
062            writer.println();
063        }
064    
065        public void addEventHandler(FormEventType type, String functionName)
066        {
067            throw new UnsupportedOperationException("addEventHandler() not supported for WML Go component.");
068        }
069    
070        protected void emitEventManagerInitialization()
071        {
072        }
073    }