label component format

package org.zkforge.converters;

import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.zkoss.util.Locales;
import org.zkoss.zk.ui.Component;
import org.zkoss.zkplus.databind.TypeConverter;

/**
 * @author Robert Pichelhofer
 * 
 * Databindingconverter
 * Direction: Output only
 * 
 * Source: Date, Timestamp
 * Destination: Label, Listcell 
 * 
 * Dateformat is retrieved from the customattribute format
 * 
 * TODO: more Examples
 * 
 * <listcell label="@{person.birthdate, converter='org.zkforge.converters.DateCustom'}"
  *  <custom-attributes format="dd.mm.yy"/></listcell>
 *
 * TODO: override the serverdefault via zk.xml
 */

public class DateCustom implements TypeConverter {

    String serverDefaultFormat;

    public DateCustom() {
	serverDefaultFormat = getDefaultFormat();
    }
    /* (non-Javadoc)
     * @see org.zkoss.zkplus.databind.TypeConverter#coerceToBean(java.lang.Object, org.zkoss.zk.ui.Component)
     */
    public Object coerceToBean(Object arg0, Component arg1) {
	// this is an output converter, no action here
	return null;
    }

    /* (non-Javadoc)
     * @see org.zkoss.zkplus.databind.TypeConverter#coerceToUi(java.lang.Object, org.zkoss.zk.ui.Component)
     */
    public Object coerceToUi(Object arg0, Component arg1) {
	if (arg0 == null) {
	    return null;
	}
	String format = (String) arg1.getAttribute("format");
        if (format == null) {
            format = serverDefaultFormat;
        }
	SimpleDateFormat sdf = new SimpleDateFormat(format);
	Date date = (Date) arg0;
	return sdf.format(date);
    }
    /**
     * Returns the default format, which is used when outputing 
     * the date
     * <p>The default format ({@link #getFormat}) depends on JVM's setting
     * and the current user's locale. That is,
     * <code>DateFormat.getDateInstance(DateFormat,DEFAULT, Locales.getCurrent).</code>
     *
     * <p>You might override this method to provide your own default format.
     */
    protected String getDefaultFormat() {
	DateFormat df = DateFormat.getDateInstance(
		DateFormat.DEFAULT, Locales.getCurrent());
	if (df instanceof SimpleDateFormat) {
	    final String fmt = ((SimpleDateFormat)df).toPattern();
	    if (fmt != null && !"M/d/yy h:mm a".equals(fmt))
		return fmt; //note: JVM use "M/d/yy h:mm a" if not found!
	}
	return "yyyy/MM/dd";
    }
}

<listcell label="@{person.birthdate, converter='org.zkforge.converters.DateUser'}"/>

package org.zkforge.converters;
...
..
public class DateUser implements TypeConverter {

  /* (non-Javadoc)
   * @see org.zkoss.zkplus.databind.TypeConverter#coerceToUi(java.lang.Object, org.zkoss.zk.ui.Component)
   */
  public Object coerceToUi(Object arg0, Component arg1) {
    if (arg0 == null) {
      return null;
    }
    SimpleDateFormat sdf = new SimpleDateFormat(getDefaultFormat());
      Date date = (Date) arg0;
      return sdf.format(date);
  }
  /**
     * Returns the default format, which is used when outputing 
     * the date
     */
    protected String getDefaultFormat() {
      DateFormat df = DateFormat.getDateInstance(
          DateFormat.DEFAULT, Locales.getCurrent());
      if (df instanceof SimpleDateFormat) {
        String fmt = ((SimpleDateFormat)df).toPattern();
        if (fmt != null && !"M/d/yy h:mm a".equals(fmt))
          return fmt; //note: JVM use "M/d/yy h:mm a" if not found!
      }
      return "yyyy/MM/dd";
    }
}

<listcell label="@{person.birthdate, converter='org.zkforge.converters.DateCustom'}"
    <custom-attributes format="dd.MM.yy"/></listcell>