Adds example for dev_mode and updates doc (#13944)

* Adds example for dev_mode and updates doc * Addresses review comments * Update frame/examples/dev-mode/src/lib.rs Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com> * Addresses review comment --------- Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
2026-04-26 12:17:58 +00:00 · 2023-04-19 16:24:19 +05:30
parent bb394e08ac
commit e458bf3795
7 changed files with 320 additions and 0 deletions
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+// This file is part of Substrate.
+
+// Copyright (C) Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! <!-- markdown-link-check-disable -->
+//! # Dev Mode Example Pallet
+//!
+//! A simple example of a FRAME pallet demonstrating
+//! the ease of requirements for a pallet in dev mode.
+//!
+//! Run `cargo doc --package pallet-dev-mode --open` to view this pallet's documentation.
+//!
+//! **Dev mode is not meant to be used in production.**
+
+// Ensure we're `no_std` when compiling for Wasm.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use frame_support::dispatch::DispatchResult;
+use frame_system::ensure_signed;
+
+// Re-export pallet items so that they can be accessed from the crate namespace.
+pub use pallet::*;
+
+#[cfg(test)]
+mod tests;
+
+/// A type alias for the balance type from this pallet's point of view.
+type BalanceOf<T> = <T as pallet_balances::Config>::Balance;
+
+/// Enable `dev_mode` for this pallet.
+#[frame_support::pallet(dev_mode)]
+pub mod pallet {
+	use super::*;
+	use frame_support::pallet_prelude::*;
+	use frame_system::pallet_prelude::*;
+
+	#[pallet::config]
+	pub trait Config: pallet_balances::Config + frame_system::Config {
+		/// The overarching event type.
+		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
+	}
+
+	// Simple declaration of the `Pallet` type. It is placeholder we use to implement traits and
+	// method.
+	#[pallet::pallet]
+	pub struct Pallet<T>(_);
+
+	#[pallet::call]
+	impl<T: Config> Pallet<T> {
+		#[pallet::call_index(0)]
+		/// No need to define a `weight` attribute here because of `dev_mode`.
+		pub fn add_dummy(origin: OriginFor<T>, id: T::AccountId) -> DispatchResult {
+			ensure_root(origin)?;
+
+			if let Some(mut dummies) = Dummy::<T>::get() {
+				dummies.push(id.clone());
+				Dummy::<T>::set(Some(dummies));
+			} else {
+				Dummy::<T>::set(Some(vec![id.clone()]));
+			}
+
+			// Let's deposit an event to let the outside world know this happened.
+			Self::deposit_event(Event::AddDummy { account: id });
+
+			Ok(())
+		}
+
+		#[pallet::call_index(1)]
+		/// No need to define a `weight` attribute here because of `dev_mode`.
+		pub fn set_bar(
+			origin: OriginFor<T>,
+			#[pallet::compact] new_value: T::Balance,
+		) -> DispatchResult {
+			let sender = ensure_signed(origin)?;
+
+			// Put the new value into storage.
+			<Bar<T>>::insert(&sender, new_value);
+
+			Self::deposit_event(Event::SetBar { account: sender, balance: new_value });
+
+			Ok(())
+		}
+	}
+
+	#[pallet::event]
+	#[pallet::generate_deposit(pub(super) fn deposit_event)]
+	pub enum Event<T: Config> {
+		AddDummy { account: T::AccountId },
+		SetBar { account: T::AccountId, balance: BalanceOf<T> },
+	}
+
+	/// The MEL requirement for bounded pallets is skipped by `dev_mode`.
+	/// This means that all storages are marked as unbounded.
+	/// This is equivalent to specifying `#[pallet::unbounded]` on this type definitions.
+	/// When the dev_mode is removed, we would need to implement implement `MaxEncodedLen`.
+	#[pallet::storage]
+	pub type Dummy<T: Config> = StorageValue<_, Vec<T::AccountId>>;
+
+	/// The Hasher requirement is skipped by `dev_mode`. So, second parameter can be `_`
+	/// and `Blake2_128Concat` is used as a default.
+	/// When the dev_mode is removed, we would need to specify the hasher like so:
+	/// `pub type Bar<T: Config> = StorageMap<_, Blake2_128Concat, T::AccountId, T::Balance>;`.
+	#[pallet::storage]
+	pub type Bar<T: Config> = StorageMap<_, _, T::AccountId, T::Balance>;
+}