Bug 180118 Enhance to print out source stack trace in preview mode.[0002]
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/presentation/aggregation/layout/FramesetFragment.java
* @return
	 */
	protected boolean __checkHTMLFormat( HttpServletRequest request )
	{
		BaseAttributeBean bean = (BaseAttributeBean) request
				.getAttribute( IBirtConstants.ATTRIBUTE_BEAN );
		assert bean != null;
		return ParameterAccessor.PARAM_FORMAT_HTML.equalsIgnoreCase( bean
				.getFormat( ) );
	}
	/**
	 * Anything before do service.
	 * 
	 * @param request
	 *            incoming http request
	 * @param response
	 *            http response
	 * @exception ServletException
	 * @exception IOException
	 */
	protected void doPreService( HttpServletRequest request,
			HttpServletResponse response ) throws ServletException, IOException
	{
		BaseAttributeBean attrBean = (BaseAttributeBean) request
				.getAttribute( IBirtConstants.ATTRIBUTE_BEAN );
		String format = attrBean.getFormat( );
		String openType = ParameterAccessor.getOpenType( request );
		if ( ParameterAccessor.PARAM_FORMAT_PDF.equalsIgnoreCase( format ) )
		{
			response.setContentType( "application/pdf" );