pallet_example_split/
lib.rs

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1// This file is part of Substrate.
2
3// Copyright (C) Parity Technologies (UK) Ltd.
4// SPDX-License-Identifier: MIT-0
5
6// Permission is hereby granted, free of charge, to any person obtaining a copy of
7// this software and associated documentation files (the "Software"), to deal in
8// the Software without restriction, including without limitation the rights to
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11// so, subject to the following conditions:
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13// The above copyright notice and this permission notice shall be included in all
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17// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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22// SOFTWARE.
23
24//! # Split Example Pallet
25//!
26//! **This pallet serves as an example and is not meant to be used in production.**
27//!
28//! A FRAME pallet demonstrating the ability to split sections across multiple files.
29//!
30//! Note that this is purely experimental at this point.
31
32#![cfg_attr(not(feature = "std"), no_std)]
33
34// Re-export pallet items so that they can be accessed from the crate namespace.
35pub use pallet::*;
36
37#[cfg(test)]
38mod mock;
39
40#[cfg(test)]
41mod tests;
42
43#[cfg(feature = "runtime-benchmarks")]
44mod benchmarking;
45mod events;
46
47pub mod weights;
48pub use weights::*;
49
50use frame_support::pallet_macros::*;
51
52/// Imports a [`pallet_section`] defined at [`events::events`].
53/// This brings the events defined in that section into the pallet's namespace.
54#[import_section(events::events)]
55#[frame_support::pallet]
56pub mod pallet {
57	use super::*;
58	use frame_support::pallet_prelude::*;
59	use frame_system::pallet_prelude::*;
60
61	#[pallet::pallet]
62	pub struct Pallet<T>(_);
63
64	/// Configure the pallet by specifying the parameters and types on which it depends.
65	#[pallet::config]
66	pub trait Config: frame_system::Config {
67		/// Type representing the weight of this pallet
68		type WeightInfo: WeightInfo;
69	}
70
71	// The pallet's runtime storage items.
72	#[pallet::storage]
73	pub type Something<T> = StorageValue<_, u32>;
74
75	// Errors inform users that something went wrong.
76	#[pallet::error]
77	pub enum Error<T> {
78		/// Error names should be descriptive.
79		NoneValue,
80		/// Errors should have helpful documentation associated with them.
81		StorageOverflow,
82	}
83
84	// Dispatchable functions allows users to interact with the pallet and invoke state changes.
85	// These functions materialize as "extrinsics", which are often compared to transactions.
86	// Dispatchable functions must be annotated with a weight and must return a DispatchResult.
87	#[pallet::call]
88	impl<T: Config> Pallet<T> {
89		/// An example dispatchable that takes a singles value as a parameter, writes the value to
90		/// storage and emits an event. This function must be dispatched by a signed extrinsic.
91		#[pallet::call_index(0)]
92		#[pallet::weight(T::WeightInfo::do_something())]
93		pub fn do_something(origin: OriginFor<T>, something: u32) -> DispatchResult {
94			// Check that the extrinsic was signed and get the signer.
95			// This function will return an error if the extrinsic is not signed.
96			let who = ensure_signed(origin)?;
97
98			// Update storage.
99			<Something<T>>::put(something);
100
101			// Emit an event.
102			Self::deposit_event(Event::SomethingStored { something, who });
103			// Return a successful DispatchResultWithPostInfo
104			Ok(())
105		}
106
107		/// An example dispatchable that may throw a custom error.
108		#[pallet::call_index(1)]
109		#[pallet::weight(T::WeightInfo::cause_error())]
110		pub fn cause_error(origin: OriginFor<T>) -> DispatchResult {
111			let _who = ensure_signed(origin)?;
112
113			// Read a value from storage.
114			match Something::<T>::get() {
115				// Return an error if the value has not been set.
116				None => return Err(Error::<T>::NoneValue.into()),
117				Some(old) => {
118					// Increment the value read from storage; will error in the event of overflow.
119					let new = old.checked_add(1).ok_or(Error::<T>::StorageOverflow)?;
120					// Update the value in storage with the incremented result.
121					<Something<T>>::put(new);
122					Ok(())
123				},
124			}
125		}
126	}
127}
pallet_example_split/lib.rs

pallet_example_split/
lib.rs
