波卡链Substrate 托盘Pallets进阶

Posted 2022-01-12 thefist11

1. 7 个部分组成：

• 导入和依赖
• 托盘类型的声明
• 运行时配置特性
• 运行时存储
• 运行时事件
• 挂钩
• 外在的Extrinsics

2.

// 1. Imports and Dependencies
pub use pallet::*;
#[frame_support::pallet]
pub mod pallet 
    use frame_support::pallet_prelude::*;
    use frame_system::pallet_prelude::*;

    // 2. Declaration of the Pallet type
    // This is a placeholder to implement traits and methods.
    #[pallet::pallet]
    #[pallet::generate_store(pub(super) trait Store)]
    #[pallet::generate_storage_info]
    pub struct Pallet<T>(_);

    // 3. Runtime Configuration Trait
    // All types and constants go here.
    // Use #[pallet::constant] and #[pallet::extra_constants]
    // to pass in values to metadata.
    #[pallet::config]
    pub trait Config: frame_system::Config  ... 

    // 4. Runtime Storage
    // Use to declare storage items.
    #[pallet::storage]
    #[pallet::getter(fn something)]
    pub MyStorage<T: Config> = StorageValue<_, u32>;

    // 5. Runtime Events
    // Can stringify event types to metadata.
    #[pallet::event]
    #[pallet::generate_deposit(pub(super) fn deposit_event)]
    pub enum Event<T: Config>  ... 

    // 6. Hooks
    // Define some logic that should be executed
    // regularly in some context, for e.g. on_initialize.
    #[pallet::hooks]
    impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T>  ... 

    // 7. Extrinsics
    // Functions that are callable from outside the runtime.
    #[pallet::call]
    impl<T:Config> Pallet<T>  ...