<s> from flask import session , abort , flash , redirect , url_for <EOL> from permission import Rule <EOL> from . . models import User <EOL> class VisitorRule ( Rule ) : <EOL> def check ( self ) : <EOL> return '<STR_LIT>' not in session <EOL> def deny ( self ) : <EOL> return redirect ( url_for ( '<STR_LIT>' ) ) <EOL> class UserRule ( Rule ) : <EOL> def check ( self ) : <EOL> return '<STR_LIT>' in session <EOL> def deny ( self ) : <EOL> flash ( '<STR_LIT>' ) <EOL> return redirect ( url_for ( '<STR_LIT>' ) ) <EOL> class AdminRule ( Rule ) : <EOL> def base ( self ) : <EOL> return UserRule ( ) <EOL> def check ( self ) : <EOL> user_id = int ( session [ '<STR_LIT>' ] ) <EOL> user = User . query . filter ( User . id == user_id ) . first ( ) <EOL> return user and user . is_admin <EOL> def deny ( self ) : <EOL> abort ( <NUM_LIT> ) </s>
