#NEWLINE# def validate( self , value , model_instance ) : #NEWLINE# #INDENT# if ( not self . editable ) : #NEWLINE# #INDENT# return #NEWLINE# #UNINDENT# if ( ( value is None ) and ( not model_instance . null ) ) : #NEWLINE# #INDENT# raise exceptions . ValidationError ( self . error_messages [ 'null' ] ) #NEWLINE# #UNINDENT# if ( ( not self . blank ) and ( value in validators . EMPTY_VALUES ) ) : #NEWLINE# #INDENT# raise exceptions . ValidationError ( self . error_messages [ 'blank' ] )