api/classy/classy_hook (Classy)

Module responsible for managing the hooks.

hook() ¶

A handle of a hook. It can be used to unregister the hook.

prio() ¶

-type prio() :: integer().

Functions registered into a hookpoint with higher priority are executed first.

hookpoint() ¶

-type hookpoint() :: atom().

Identifier of a hookpoint.

first_match(Hookpoint, Args) ¶

-spec first_match(hookpoint(), list()) -> {ok, _Val} |
                                          undefined.

Return result of the first hook that returned {ok, _} for a given set of arguments.

all(Hookpoint, Args) ¶

-spec all(hookpoint(), list()) -> ok | {error, _}.

Ensure that all functions hooked into Hookpoint return ok.

If any function returns other value or throws an exception, this function returns {error, _}.

fold(Hookpoint, Args, Acc0) ¶

-spec fold(hookpoint(), list(), A) -> A.

Fold over all functions registered in Hookpoint. Accumulator argument is appended to the Args list.

Errors are ignored (logged).

foreach(Hookpoint, Args) ¶

-spec foreach(hookpoint(), list()) -> ok.

Apply all functions hooked into Hookpoint to arguments Args.

Errors are ignored (logged).

unhook(Key) ¶

-spec unhook(hook()) -> ok.

Remove a previously inserted hook.

insert(Hookpoint, Hook, Prio) ¶

-spec insert(hookpoint(), fun(), prio()) -> hook().