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/Module.java
}
		return null;
	}
	/**
	 * Gets all the defined property bindings for the given element. Each one in
	 * the list is instance of <code>PropertyBinding</code>.
	 * 
	 * @param element
	 *            the element to find
	 * @return the property binding list defined for the element
	 */
	public List getPropertyBindings( DesignElement element )
	{
		if ( element == null )
			return Collections.EMPTY_LIST;
		List propertyBindings = getListProperty( this, PROPERTY_BINDINGS_PROP );
		if ( propertyBindings == null )
			return Collections.EMPTY_LIST;
		List result = new ArrayList( );
		for ( int i = 0; i < propertyBindings.size( ); i++ )
		{
			PropertyBinding propBinding = (PropertyBinding) propertyBindings
					.get( i );
			BigDecimal id = propBinding.getID( );
			if ( id != null && getElementByID( id.longValue( ) ) == element )
				result.add( propBinding );
		}
		return result;
	}
}