Bug 207250 Check blank value for datetime type parameter from url.[0002][0705]
Description: Check blank value for datetime type parameter from url. Build number:2.3.0.v20071023 Steps to reproduce: 1. New a datetime parameter mydt,listbox, tick off isRequired. 2. Preview in external browser and add "&dt=" in url, press enter. Expected result: Error message to indicate blank value isn't allowed for this parameter. Actual result: No error message and blank value is accepted. I tried to new a jsp and use <birt:paramDef> to pass the blank value and the blank value is accepted,too. Error log:n/a
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
}
	/**
	 * Check whether show parameter page or not
	 * 
	 * @param request
	 * @return
	 */
	private boolean checkShowParameterPage( HttpServletRequest request )
	{
		if ( !ParameterAccessor.HEADER_REQUEST_TYPE_SOAP
				.equalsIgnoreCase( this.requestType )
				&& !IBirtConstants.SERVLET_PATH_DOWNLOAD
						.equalsIgnoreCase( request.getServletPath( ) ) )
		{
			String showParameterPage = ParameterAccessor
					.getShowParameterPage( request );
			if ( "false".equalsIgnoreCase( showParameterPage ) ) 
			{
				return false;
			}
			if ( "true".equalsIgnoreCase( showParameterPage ) ) 
			{
				return true;
			}
		}
		return this.missingParameter;
	}
	/**
	 * parse paramenters from config file.
	 *