Bug 121352 The data set binding property cannot be retrieved in report preview layout
In report preview page, the datasource/dataset property binding lists cannot be retrieved. The dataset binding can not work correctly in layout preview because it's value cannot get from the binding list. But in the data set edit page, the binding value can be got. You can refer to the attachment.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
return new ArrayList( userProperties.values( ) );
	}
	/**
	 * Checks if this element derives from the given element. The check is true
	 * if this element derives from the target, or if the target is an ancestor
	 * of this element.
	 * 
	 * @param element
	 *            The potential ancestor.
	 * @return True if the given element is an ancestor of this element, false
	 *         otherwise.
	 */
	public boolean isKindOf( DesignElement element )
	{
		DesignElement e = this;
		while ( e != null )
		{
			if ( e == element )
				return true;
			e = e.getExtendsElement( );
		}
		return false;
	}
	/**
	 * Determines if any elements extend this element.
	 * 
	 * @return True if the element is extended, false if not.
	 */
	public boolean hasDerived( )
	{