example controller

psudo Prolog web framework controller code

/*
 * /users/edit/<user id>
 * I am editing a user.
 */
get( users, edit, ID ) :-
  number( ID ),
  is_admin or session( id, ID ),
  users:get_user( ID, User ),
  users:view( edit, User ).

/*
 * /users/edit
 * I am editing a user, haven't said who, so default to edit me.
 */
get( users, edit ) :-
  session( id, MyID ),
  get( users, edit, MyID ).

/*
 * /users/<user id>
 * View a specific user.
 */
get( users, ID ) :-
  number( ID ),
  users:get_username( ID, Username ),
  users:view( Username ).

/*
 * /users/me
 * View a user, default to myself.
 */
get( users, me ) :-
  session( id, MyID ),
  get( users, MyID ).

/*
 * /users/<something>
 * View a user, but they weren't found.
 */
get( users, _ ) :-
  users:view( not_found ).

/*
 * /users
 * List all users.
 */
get( users ) :-
  users:get_all_users( Users ),
  users:view( list, Users ).