I think this is still broken. If I try to create a new domain called abc, with a basetype of text, then hit the + button to add a constraint, I get:
domain.js:24Uncaught TypeError: Cannot read property 'server' of undefined at s.initialize (domain.js:24) at s.e.Model (backbone-min.js:1) at s [as constructor] (backbone-min.js:1) at new s (backbone-min.js:1) at s._prepareModel (backbone-min.js:1) at set (backbone-min.js:1) at s.add (backbone-min.js:1) at s.insertRow (backgrid.min.js:8) at s.insertRow (backgrid.min.js:8) at HTMLButtonElement.<anonymous> (backform.pgadmin.js:1347)