javax.faces.webapp: public class: ConverterTag

javax.faces.webapp
public class: ConverterTag [javadoc | source]

java.lang.Object
   javax.servlet.jsp.tagext.TagSupport
      javax.faces.webapp.ConverterTag

All Implemented Interfaces:
IterationTag, Serializable

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.

ConverterTag is a base class for all JSP custom actions that create and register a Converter instance on the 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 Converter occurs only if the corresponding 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 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 Converter instance. Any configuration properties that specify behavior of this 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 Converter creation.

Fields inherited from javax.servlet.jsp.tagext.TagSupport:
id, pageContext, class$javax$servlet$jsp$tagext$Tag

Method from javax.faces.webapp.ConverterTag Summary:
createConverter, doStartTag, release, setBinding, setConverterId

Methods from javax.servlet.jsp.tagext.TagSupport:
class$, doAfterBody, doEndTag, doStartTag, findAncestorWithClass, getId, getParent, getValue, getValues, release, removeValue, setId, setPageContext, setParent, setValue

Methods from java.lang.Object:
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from javax.faces.webapp.ConverterTag Detail:
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 (binding != null) { try { vb = context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), binding, 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 (converterId != null) { try { String converterIdVal = converterId; if (UIComponentTag.isValueReference(converterId)) { ValueExpression idBinding = context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), converterId, Object.class); converterIdVal = (String) idBinding.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; } Deprecated! Create and return a new Converter to be registered on our surrounding UIComponent .
public int doStartTag() throws JspException { // Locate our parent UIComponentTag UIComponentClassicTagBase tag = UIComponentClassicTagBase.getParentUIComponentClassicTagBase(pageContext); 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 (SKIP_BODY); } 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 (binding != null) { converterError = binding; } if (converterId != null) { if (converterError != null) { converterError += " or " + converterId; } else { converterError = converterId; } } // 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, (String) localValue); vh.setValue(localValue); } catch (ConverterException ce) { // PENDING - Ignore? Throw an exception? Set the local // value back to "null" and log a warning? } } return (SKIP_BODY); } Deprecated! Create a new instance of the specified Converter class, and register it with the UIComponent instance associated with our most immediately surrounding UIComponentTag instance, if the UIComponent instance was created by this execution of the containing JSP page. If the localValue of the UIComponent is a String, attempt to convert it.
public void release() { this.converterId = null; } Deprecated! Release references to any acquired resources.
public void setBinding(String binding) throws JspException { if (binding!= null && !UIComponentTag.isValueReference(binding)) { // PENDING i18n throw new JspException("Invalid Expression:"+binding); } this.binding = binding; } Deprecated! Set the expression that will be used to create a ValueExpression that references a backing bean property of the Converter instance to be created.
public void setConverterId(String converterId) { this.converterId = converterId; } Deprecated! Set the identifer of the Converter instance to be created.

Method from javax.faces.webapp.ConverterTag Detail:

 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 (binding != null) {
            try {
		vb = 
                context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), binding, 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 (converterId != null) {
            try {
                String converterIdVal = converterId;
                if (UIComponentTag.isValueReference(converterId)) {
                    ValueExpression idBinding =
                        context.getApplication().getExpressionFactory().createValueExpression(context.getELContext(), converterId, Object.class);
                    converterIdVal = (String) idBinding.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;
}

Deprecated!

Create and return a new Converter to be registered on our surrounding UIComponent .

 public int doStartTag() throws JspException {
        // Locate our parent UIComponentTag
        UIComponentClassicTagBase tag =
            UIComponentClassicTagBase.getParentUIComponentClassicTagBase(pageContext);
        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 (SKIP_BODY);
        }
        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 (binding != null) {
                converterError = binding;
            }
            if (converterId != null) {
                if (converterError != null) {
                    converterError += " or " + converterId;
                } else {
                    converterError = converterId;
                }
            }
            // 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, (String) localValue);
                vh.setValue(localValue);
            }
            catch (ConverterException ce) {
                // PENDING - Ignore?  Throw an exception?  Set the local
                // value back to "null" and log a warning?
            }
        }        
        return (SKIP_BODY);
}

Deprecated!

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

 public  void release() {
        this.converterId = null;
}

Deprecated!

Release references to any acquired resources.

 public  void setBinding(String binding) throws JspException {
        if (binding!= null && !UIComponentTag.isValueReference(binding)) {
            // PENDING i18n
            throw new JspException("Invalid Expression:"+binding);
        }
        this.binding = binding;
}

Deprecated!

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

 public  void setConverterId(String converterId) {
        this.converterId = converterId;
}

Deprecated!

Set the identifer of the Converter instance to be created.