config.md

Configure the pallet to emit events

Every pallet has a Rust "trait" called Config. You use this trait to configure the settings that your specific pallet requires. For this tutorial, the configuration setting enables the pallet to emit events.

To define the Config trait for the proof-of-existence pallet:

1. Open the pallets/template/src/lib.rs file in a text editor.

2. Replace the #[pallet::config] line with the following code block:

   /// Configure the pallet by specifying the parameters and types on which it depends.
   #[pallet::config]
   pub trait Config: frame_system::Config {
   	/// Because this pallet emits events, it depends on the runtime's definition of an event.
   	type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
   }

3. Save your changes.

Solution

#![cfg_attr(not(feature = "std"), no_std)]

// Re-export pallet items so that they can be accessed from the crate namespace.
pub use pallet::*;

#[frame_support::pallet]
pub mod pallet {
	use super::*;
	use frame_support::pallet_prelude::*;
	use frame_system::pallet_prelude::*;

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

	/// Configure the pallet by specifying the parameters and types on which it depends.
	#[pallet::config]
	pub trait Config: frame_system::Config {
		/// Because this pallet emits events, it depends on the runtime's definition of an event.
		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
	}

	#[pallet::event]   // <-- Step 3. code block will replace this.
	#[pallet::error]   // <-- Step 4. code block will replace this.
	#[pallet::storage] // <-- Step 5. code block will replace this.
	#[pallet::call]    // <-- Step 6. code block will replace this.
}