Bug 136241 [regression]Preview template in web viewer and pdf didn't get correct effect.
Description: Preview template items in web viewer and pdf didn't get correct effect. Steps to reproduce: 1. Create template items. 2. Preview in Web Viewer and pdf. Expected result: Same effect as in html. Actual result: In web viewer, see only blank box. In pdf, blank page.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
return null;
		return prop.getDisplayValue( module, value );
	}
	/**
	 * Sets an unresolved extends name. The resolved relationships is not
	 * cached; it must be resolved later.
	 * 
	 * @param name
	 *            the name of the new parent element, or null if this element
	 *            does not extend any other element
	 */
	public void setExtendsName( String name )
	{
		setExtendsElement( null );
		name = StringUtil.trimString( name );
		if ( name == null )
			return;
		String namespace = StringUtil.extractNamespace( name );
		name = StringUtil.extractName( name );
		extendsRef = new ElementRefValue( namespace, name );
	}
	/**
	 * Validates this element and its contents.
	 * 
	 * @param module
	 *            the module
	 * @return the list of the errors found in validation, each of which is the
	 *         <code>SemanticException</code> object.
	 */
	public final List validateWithContents( Module module )