Trait near_contract_standards_sbt::fungible_token::receiver::FungibleTokenReceiver

source · 
pub trait FungibleTokenReceiver {
    fn ft_on_transfer(
        &mut self,
        sender_id: AccountId,
        amount: U128,
        msg: String
    ) -> PromiseOrValue<U128>;
}

Required Methods§

Called by fungible token contract after ft_transfer_call was initiated by sender_id of the given amount with the transfer message given in msg field. The amount of tokens were already transferred to this contract account and ready to be used.

The method must return the amount of tokens that are not used/accepted by this contract from the transferred amount. Examples:

  • The transferred amount was 500, the contract completely takes it and must return 0.
  • The transferred amount was 500, but this transfer call only needs 450 for the action passed in the msg field, then the method must return 50.
  • The transferred amount was 500, but the action in msg field has expired and the transfer must be cancelled. The method must return 500 or panic.

Arguments:

  • sender_id - the account ID that initiated the transfer.
  • amount - the amount of tokens that were transferred to this account in a decimal string representation.
  • msg - a string message that was passed with this transfer call.

Returns the amount of unused tokens that should be returned to sender, in a decimal string representation.

Implementors§