basicpropertytag.java

webwork source

/*
 * WebWork, Web Application Framework
 *
 * Distributable under Apache license.
 * See terms of license at opensource.org
 */
package webwork.view.taglib;

import webwork.util.TextUtil;
import webwork.util.BeanUtil;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import javax.servlet.jsp.PageContext;
import java.util.Iterator;

import org.apache.commons.logging.*;

/**
 *  Access the value of a named property. By default (implicitly),
 *  this tag will escape its contents if it does *not* have a body.
 *  If it does have a body, the tag will not escape the contents.
 *  You can explicitly tell the tag to escape or not.
 *  Quoted text that is escaped will have its quotes stripped off.
 *
 * @author Rickard 謆erg ([e-mail])
 * @author Matt Baldree ([e-mail])
 * @version $Revision: 1.7 $
 */
public class BasicPropertyTag
      extends WebWorkBodyTagSupport
{
   protected static Log log = LogFactory.getLog(BasicPropertyTag.class);

   // Attributes ----------------------------------------------------
   protected String valueAttr;
   protected Boolean escape;
   protected boolean hadBody;

   // Public --------------------------------------------------------
   public void setValue(String inName)
   {
      valueAttr = inName;
   }

   public void setEscape(boolean inEscape)
   {
      escape = new Boolean(inEscape);
   }

   // BodyTag implementation ----------------------------------------
   public int doStartTag() throws JspException
   {
      hadBody = false;
      Object value = findValue(valueAttr);
      getStack().pushValue(value);

      String id = getId();
      if (id != null && value != null) {
         pageContext.setAttribute(id, value);
         pageContext.setAttribute(id, value, PageContext.REQUEST_SCOPE);
      }
      return EVAL_BODY_BUFFERED;
   }

   public int doAfterBody() throws JspException
   {
      // This is a workaround for a bug in Jasper.
      // http://znutar.cortexity.com/BugRatViewer/ShowReport/652
      // Resin 1.2.1 also has this bug (i.e. body is called even though it is empty)

      // If the bodyContent is null then just return
      if (bodyContent == null)
         return SKIP_BODY;
      String body = null;
      try {
         body = bodyContent.getString();
      } catch (Exception e) {
         //do nothing - leave body as null
      }

      //Added null check - Fixes WW-195 on Resin.
      hadBody = body != null && body.length() != 0;

      if (hadBody) {
         try {
            if (shouldEscape()) {
               body = TextUtil.escapeHTML(body);
            }
            bodyContent.getEnclosingWriter().write(body);
         } catch (java.io.IOException e) {
            throw new JspTagException("Could not show attribute " + valueAttr + ":" + e);
         }
      }
      return SKIP_BODY;
   }

   public int doEndTag() throws JspException
   {
      Object value = getStack().popValue();

      if (!hadBody) {
         // No body used. This means that we want to print the parameter out
         try {
            //LogFactory.getLog(this.getClass()).debug("Property value:"+value);
            if (value != null && getId() == null)
               if (value instanceof Iterator) {
                  Iterator enum = (Iterator) value;
                  if (enum.hasNext()) {
                     if (shouldEscape()) {
                        pageContext.getOut().write(TextUtil.escapeHTML(BeanUtil.toStringValue(enum.next())));
                     } else {
                        pageContext.getOut().write(BeanUtil.toStringValue(enum.next()));
                     }
                  }
               } else if (value instanceof char[]) {
                  if (shouldEscape()) {
                     pageContext.getOut().write(TextUtil.escapeHTML(String.valueOf((char[]) value)));
                  } else {
                     pageContext.getOut().write(String.valueOf((char[]) value));
                  }
               } else {
                  if (shouldEscape()) {
                     pageContext.getOut().write(TextUtil.escapeHTML(BeanUtil.toStringValue(value)));
                  } else {
                     pageContext.getOut().write(BeanUtil.toStringValue(value));
                  }
               }
            else
               pageContext.getOut().write(""); // Printing out null gives no output
         } catch (Throwable t) {
            String msg = "Could not show value: " + valueAttr;
            log.error(msg, t);
            throw new JspException(msg + ", throwable: " + t);
         }
      }

      return EVAL_PAGE;
   }

    /**
     * The BasicPropertyTag should escape IF the escape value has been set to true. At
     * all other times it will false (ie not escape data).
     *
     * CHANGE THIS METHOD ON PAIN OF DEATH -mike :)
     *
     * @see PropertyTag#shouldEscape()
     */
    protected boolean shouldEscape()
    {
        if (escape == null)
        {
            return false;
        }

        return escape.booleanValue();
    }
}