PSP22 Pallet

This example shows how you can reuse the implementation of PSP22 Pallet via pallet-assets chain extension. Also, this example shows how you can customize the logic, for example, to get current asset_id.

Step 1: Implement features

With default Cargo.toml, you need to enable psp22-pallet feature, embed modules data structures and implement them via #[openbrush::implementation] macro as described in that section.

Use psp22_pallet storage and implement PSP22 for your contract.

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

#[openbrush::implementation(PSP22Pallet)]
#[openbrush::contract]
pub mod my_psp22_pallet {
    use openbrush::traits::Storage;

    #[ink(storage)]
    #[derive(Default, Storage)]
    pub struct Contract {
        #[storage_field]
        pallet: psp22_pallet::Data,
    }
}

Step 3: Add constructor

Add constructor for your contract, create asset and mint tokens to caller.

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

#[openbrush::implementation(PSP22Pallet)]
#[openbrush::contract]
pub mod my_psp22_pallet {
    use openbrush::traits::Storage;

    #[ink(storage)]
    #[derive(Default, Storage)]
    pub struct Contract {
        #[storage_field]
        pallet: psp22_pallet::Data,
    }

    impl Contract {
        /// During instantiation of the contract, you need to pass native tokens as a deposit
        /// for asset creation.
        #[ink(constructor)]
        #[ink(payable)]
        pub fn new(asset_id: u32, min_balance: Balance, total_supply: Balance) -> Self {
            let mut instance = Self::default();

            psp22_pallet::Internal::_create(&mut instance, asset_id, Self::env().account_id(), min_balance)
                .expect("Should create an asset");
            instance.pallet.asset_id.set(&asset_id);
            instance.pallet.origin.set(&Origin::Caller);
            psp22_pallet::Internal::_mint_to(&mut instance, Self::env().caller(), total_supply).expect("Should mint");

            instance
        }

        /// Asset id of the asset in the `pallet-assets`
        #[ink(message)]
        pub fn asset_id(&self) -> u32 {
            self.pallet.asset_id.get_or_default()
        }
    }
}

You can check an example of the usage of PSP22 Pallet.

Also you can use extensions for PSP22 token:

PSP22 Pallet Metadata: metadata for PSP22 Pallet.

PSP22 Pallet Mintable: creation of new tokens.

PSP22 Pallet Burnable: destruction of own tokens.