Attribute Macro frame_support::pallet_macros::hooks
source · #[hooks]
Expand description
The #[pallet::hooks]
attribute allows you to specify a Hooks
implementation for
Pallet
that specifies pallet-specific logic.
The item the attribute attaches to must be defined as follows:
#[pallet::hooks]
impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> $optional_where_clause {
...
}
I.e. a regular trait implementation with generic bound: T: Config
, for the trait
Hooks<BlockNumberFor<T>>
(they are defined in preludes), for the type Pallet<T>
and
with an optional where clause.
If no #[pallet::hooks]
exists, then the following default implementation is
automatically generated:
#[pallet::hooks]
impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
Macro expansion
The macro implements the traits OnInitialize
, OnIdle
, OnFinalize
, OnRuntimeUpgrade
,
OffchainWorker
, and IntegrityTest
using the provided Hooks
implementation.
NOTE: OnRuntimeUpgrade
is implemented with Hooks::on_runtime_upgrade
and some
additional logic. E.g. logic to write the pallet version into storage.
NOTE: The macro also adds some tracing logic when implementing the above traits. The
following hooks emit traces: on_initialize
, on_finalize
and on_runtime_upgrade
.