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  /*
   * $Id: ConverterTag.java,v 1.24 2007/01/29 07:29:01 rlubke Exp $
   */
  
  /*
   * The contents of this file are subject to the terms
   * of the Common Development and Distribution License
   * (the License). You may not use this file except in
   * compliance with the License.
  * 
  * You can obtain a copy of the License at
  * https://javaserverfaces.dev.java.net/CDDL.html or
  * legal/CDDLv1.0.txt. 
  * See the License for the specific language governing
  * permission and limitations under the License.
  * 
  * When distributing Covered Code, include this CDDL
  * Header Notice in each file and include the License file
  * at legal/CDDLv1.0.txt.    
  * If applicable, add the following below the CDDL Header,
  * with the fields enclosed by brackets [] replaced by
  * your own identifying information:
  * "Portions Copyrighted [year] [name of copyright owner]"
  * 
  * [Name of File] [ver.__] [Date]
  * 
  * Copyright 2005 Sun Microsystems Inc. All Rights Reserved
  */
 
 package javax.faces.webapp;
 

ConverterTag is a base class for all JSP custom actions that create and register a Converter instance on the javax.faces.component.ValueHolder associated with our most immediate surrounding instance of a tag whose implementation class is a subclass of UIComponentTag. To avoid creating duplicate instances when a page is redisplayed, creation and registration of a javax.faces.convert.Converter occurs only if the corresponding javax.faces.component.UIComponent was created (by the owning UIComponentTag) during the execution of the current page.

This class may be used directly to implement a generic converter registration tag (based on the converter-id specified by the converterId attribute), or as a base class for tag instances that support specific javax.faces.convert.Converter subclasses. This converterId attribute must refer to one of the well known converter-ids, or a custom converter-id as defined in a faces-config.xml file.

Subclasses of this class must implement the createConverter() method, which creates and returns a javax.faces.convert.Converter instance. Any configuration properties that specify behavior of this javax.faces.convert.Converter must have been set by the createConverter() method. Generally, this occurs by copying corresponding attribute values on the tag instance.

This tag creates no output to the page currently being created. It is used solely for the side effect of javax.faces.convert.Converter creation.

Deprecated:
This has been partially replaced by ConverterELTag. The remainder of the functionality, namely, the binding facility and the implementation of the createConverter() method, is now an implementation detail.
 
 
 public class ConverterTag extends TagSupport {
 
 
     // ---------------------------------------------------------- Static Members
 
 
     private static final long serialVersionUID = -5909792518081427720L;
 
 
     // -------------------------------------------------------------- Attributes
 
    

The identifier of the javax.faces.convert.Converter instance to be created.

 
     private String converterId = null;
    
    

The javax.el.ValueExpression that evaluates to an object that implements javax.faces.convert.Converter.

    private String binding = null;

    

Set the identifer of the javax.faces.convert.Converter instance to be created.

Parameters:
converterId The identifier of the converter instance to be created.
    public void setConverterId(String converterId) {
        this. = converterId;
    }

    

Set the expression that will be used to create a javax.el.ValueExpression that references a backing bean property of the javax.faces.convert.Converter instance to be created.

Parameters:
binding The new expression
Throws:
javax.servlet.jsp.JspException if a JSP error occurs
    public void setBinding(String binding
        throws JspException {
        if (binding!= null && !UIComponentTag.isValueReference(binding)) {
            // PENDING i18n
            throw new JspException("Invalid Expression:"+binding);
        }
        this. = binding;
    }
    // ---------------------------------------------------------- Public Methods


    

Create a new instance of the specified javax.faces.convert.Converter class, and register it with the javax.faces.component.UIComponent instance associated with our most immediately surrounding UIComponentTag instance, if the javax.faces.component.UIComponent instance was created by this execution of the containing JSP page. If the localValue of the javax.faces.component.UIComponent is a String, attempt to convert it.

Throws:
javax.servlet.jsp.JspException if a JSP error occurs
    public int doStartTag() throws JspException {
        // Locate our parent UIComponentTag
        UIComponentClassicTagBase tag =
            UIComponentClassicTagBase.getParentUIComponentClassicTagBase();
        if (tag == null) { // PENDING - i18n
            throw new JspException("Not nested in a UIComponentTag Error for tag with handler class:"+
                    this.getClass().getName());
        }
        // Nothing to do unless this tag created a component
        if (!tag.getCreated()) {
            return ();
        }
        UIComponent component = tag.getComponentInstance();
        if (component == null) {            
            //PENDING i18n
            throw new JspException("Can't create Component from tag.");
        }
        if (!(component instanceof ValueHolder)) {
            //PENDING i18n
            throw new JspException("Not nested in a tag of proper type. Error for tag with handler class:"+
                    this.getClass().getName());
        }
        
        Converter converter = createConverter();
        
        if (converter == null) {
            //noinspection NonConstantStringShouldBeStringBuffer
            String converterError = null;
            if ( != null) {
                converterError = ;
            }
            if ( != null) {
                if (converterError != null) {
                    converterError += " or " + ;
                } else {
                    converterError = ;
                }
            }
            // PENDING i18n
            throw new JspException("Can't create class of type:"+
                    "javax.faces.convert.Converter for:"+converterError);
        }
        ValueHolder vh = (ValueHolder)component;
        FacesContext context = FacesContext.getCurrentInstance();
        
        // Register an instance with the appropriate component
        vh.setConverter(converter);
        
        // Once the converter has been set, attempt to convert the
        // incoming "value"
        Object localValue = vh.getLocalValue();
        if (localValue instanceof String) {
            try {
                localValue = converter.getAsObject(context, (UIComponent)vh, (StringlocalValue);
                vh.setValue(localValue);
            }
            catch (ConverterException ce) {
                // PENDING - Ignore?  Throw an exception?  Set the local
                // value back to "null" and log a warning?
            }
        }        
  
        return ();
    }


    

Release references to any acquired resources.

    public void release() {
        this. = null;
    }
    // ------------------------------------------------------- Protected Methods


    

Create and return a new javax.faces.convert.Converter to be registered on our surrounding javax.faces.component.UIComponent.

Throws:
javax.servlet.jsp.JspException if a new instance cannot be created
    protected Converter createConverter()
        throws JspException {
        FacesContext context = FacesContext.getCurrentInstance();
        Converter converter = null;
        ValueExpression vb = null;
        
        // If "binding" is set, use it to create a converter instance.
        if ( != null) {
            try {
		vb = 
                context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), Object.class);
		if (vb != null) {
                    converter = (Converter)vb.getValue(context.getELContext());
                    if (converter != null) {
                        return converter;
                    }
                }
            } catch (Exception e) {
                throw new JspException(e);
            }
        }
        // If "converterId" is set, use it to create the converter
        // instance.  If "converterId" and "binding" are both set, store the 
        // converter instance in the value of the property represented by
        // the value binding expression.      
        if ( != null) {
            try {
                String converterIdVal = ;
                if (UIComponentTag.isValueReference()) {
                    ValueExpression idBinding =
                        context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), Object.class);
                    converterIdVal = (StringidBinding.getValue(context.getELContext());
                }
                converter = context.getApplication().createConverter(converterIdVal);
                if (converter != null) {
                    if (vb != null) {
                        vb.setValue(context.getELContext(), converter);
                    }
                }
            } catch (Exception e) {
                throw new JspException(e);
            }
        }
        return converter;
    }
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