Attribute Macro hooks

#[hooks]

The #[pallet::hooks] attribute allows you to specify a frame_support::traits::Hooks implementation for Pallet that specifies pallet-specific logic.

The item the attribute attaches to must be defined as follows:

#[frame_support::pallet]
mod pallet {
	#[pallet::pallet]
	pub struct Pallet<T>(_);

	#[pallet::hooks]
	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
		// Implement hooks here
	}
}

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>.

Optionally, you could add a where clause.

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.

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Documentation for this macro can be found at frame_support::pallet_macros::hooks.