Overview

The PaymentsModule trait defines the functionalities related to handling payments within a smart contract on the MultiversX blockchain. It includes the ability to whitelist acceptable payment tokens and to process deposits.

Functionalities

Whitelisting Tokens

• add_accepted_payment_tokens(accepted_tokens: MultiValueEncoded<EgldOrEsdtTokenIdentifier>)
  • This admin-only function allows the contract owner to whitelist acceptable payment tokens by inserting them into the accepted_payment_tokens set.

Deposit

• deposit()
  • Users can deposit funds into the contract. The function checks that the payment amount is non-zero and that the payment token is whitelisted.

Withdraw

• withdraw(tokens_to_withdraw: MultiValueEncoded<MultiValue2<EgldOrEsdtTokenIdentifier, BigUint>>)
  • Users can withdraw their funds at any time. It checks what type of tokens are being withdrew and it treats the case accordingly.

Usage

• The deposit function is marked as #[payable("*")], which means it can accept a payment in EGLD or any single fungible ESDT token.
• When calling deposit, the caller must send an acceptable payment token and a positive payment amount.

Important Notes

• The #[only_owner] macro restricts the add_accepted_payment_tokens function to the contract owner.
• Error messages such as "No payment amount provided" and "Invalid payment token provided" ensure that the function calls adhere to the contract's requirements.