001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *   http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing,
013     * software distributed under the License is distributed on an
014     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     * KIND, either express or implied.  See the License for the
016     * specific language governing permissions and limitations
017     * under the License.
018     */
019    
020    package org.apache.myfaces.tobago.taglib.component;
021    
022    import org.apache.myfaces.tobago.apt.annotation.Tag;
023    import org.apache.myfaces.tobago.apt.annotation.BodyContent;
024    import org.apache.myfaces.tobago.apt.annotation.TagAttribute;
025    import org.apache.myfaces.tobago.component.ComponentUtil;
026    import static org.apache.myfaces.tobago.TobagoConstants.ATTR_CONVERTER;
027    
028    import javax.servlet.jsp.tagext.TagSupport;
029    import javax.servlet.jsp.JspException;
030    import javax.faces.webapp.UIComponentTag;
031    import javax.faces.component.UIComponent;
032    import javax.faces.component.ValueHolder;
033    import javax.faces.el.ValueBinding;
034    import javax.faces.context.FacesContext;
035    import javax.faces.convert.Converter;
036    
037    /*
038     * Date: Oct 13, 2006
039     * Time: 6:01:59 PM
040     */
041    /**
042     * Register an Converter instance on the UIComponent
043     * associated with the closest parent UIComponent.
044     */
045    @Tag(name = "converter", bodyContent = BodyContent.EMPTY)
046    public class ConverterTag extends TagSupport {
047    
048      private static final long serialVersionUID = 8565994799165107984L;
049    
050      /**
051       * The converterId of the {@link javax.faces.convert.Converter}
052       */
053      private String converterId;
054      private String binding;
055    
056      /**
057       * The converterId of a registered converter.
058       *
059       * @param converterId A valid converterId
060       */
061      @TagAttribute()
062      public void setConverterId(String converterId) {
063        this.converterId = converterId;
064      }
065    
066      /**
067       * The value binding expression to a converter.
068       *
069       * @param binding A valid binding
070       */
071      @TagAttribute
072      public void setBinding(String binding) {
073        this.binding = binding;
074      }
075    
076      /**
077       * Create a new instance of the specified {@link javax.faces.convert.Converter}
078       * class, and register it with the {@link javax.faces.component.UIComponent} instance associated
079       * with our most immediately surrounding {@link javax.faces.webapp.UIComponentTag} instance, if
080       * the {@link javax.faces.component.UIComponent} instance was created by this execution of the
081       * containing JSP page.
082       *
083       * @throws javax.servlet.jsp.JspException if a JSP error occurs
084       */
085      public int doStartTag() throws JspException {
086    
087        // Locate our parent UIComponentTag
088        UIComponentTag tag =
089            UIComponentTag.getParentUIComponentTag(pageContext);
090        if (tag == null) {
091          // TODO Message resource i18n
092          throw new JspException("Not nested in faces tag");
093        }
094    
095        if (!tag.getCreated()) {
096          return (SKIP_BODY);
097        }
098    
099        UIComponent component = tag.getComponentInstance();
100        if (component == null) {
101          // TODO Message resource i18n
102          throw new JspException("Component Instance is null");
103        }
104        if (!(component instanceof ValueHolder)) {
105          // TODO Message resource i18n
106          throw new JspException("Component " + component.getClass().getName() + " is not instanceof ValueHolder");
107        }
108        ValueHolder valueHolder = (ValueHolder) component;
109    
110        Converter converter = null;
111    
112        if (binding != null && UIComponentTag.isValueReference(binding)) {
113          ValueBinding valueBinding = ComponentUtil.createValueBinding(binding);
114          if (valueBinding != null) {
115            Object obj = valueBinding.getValue(FacesContext.getCurrentInstance());
116            if (obj != null && obj instanceof Converter) {
117              converter = (Converter) obj;
118            }
119          }
120        }
121    
122        if (converter == null && converterId != null) {
123          String localConverterId;
124          // evaluate any VB expression that we were passed
125          if (UIComponentTag.isValueReference(converterId)) {
126            ValueBinding typeValueBinding = ComponentUtil.createValueBinding(converterId);
127            localConverterId = (String) typeValueBinding.getValue(FacesContext.getCurrentInstance());
128          } else {
129            localConverterId = converterId;
130          }
131          converter = FacesContext.getCurrentInstance().getApplication().createConverter(localConverterId);
132          if (converter != null && binding != null) {
133            ComponentUtil.setValueForValueBinding(binding, converter);
134          }
135        }
136        if (converter != null) {
137          if (UIComponentTag.isValueReference(binding)) {
138            component.setValueBinding(ATTR_CONVERTER, ComponentUtil.createValueBinding(binding));
139          } else {
140            valueHolder.setConverter(converter);
141          }
142        }
143        // TODO else LOG.warn?
144        return (SKIP_BODY);
145      }
146    
147    
148      /**
149       * <p>Release references to any acquired resources.
150       */
151      public void release() {
152        this.converterId = null;
153        this.binding = null;
154      }
155    
156    
157    }