Open-cell spray foam is an air barrier, but is vapor permeable. The figure above shows the XPS insulation detail required at the above grade portion of the foundation wall for cold climate construction to minimize moisture condensation at the cold concrete in the winter months, and minimize inward driven vapor in the summer months.
How to Install XPS (extruded polystyrene) foam-board insulation. Score-and-snap, no vapor barrier - it is not too difficult. XPS insulation has a lot to offer: click-thru to read about its specifications and installation instructions.