changed disable_with option (to be deprecated in rails 4.1)
clarified what PRT type we are refering to in the scenarios
removed legend from fieldset. Added css classes to sections form-inputs and form-actions
added measurements as polymorphic association. #range is now an instance method for consistency accross meters. Added comments and reorganized method placement.
added measurements as polymorphic association. Added range instance method. Added placeholder method for #r (inverse t90 function).
removed Instrument model since this will be represented through a polymorphic association to :meter
removed instrument association. Added meter polymorphic association.
swapped association :iec60751_prt with association :meter
removed instruments relation, index and foreign key. Added polymorphic relation meter, and index on [meter_id, meter_type]
updated :prt_measurement factory to conditionally associate to different types of :meter
added measurements as polymorphic association. #range is now an instance method for consistency accross meters.
added measurements as polymorphic association. Added placeholder method for #r (inverse t90 function).
removed :instrument association. Added :meter polymorphic association.
using :meter association and builder with custom :iec60751_prt meter. Using range instance method (was class method)