near_contract_standards::non_fungible_token::core

Trait NonFungibleTokenCore

Source 
pub trait NonFungibleTokenCore {
    // Required methods
    fn nft_transfer(
        &mut self,
        receiver_id: AccountId,
        token_id: TokenId,
        approval_id: Option<u64>,
        memo: Option<String>,
    );
    fn nft_transfer_call(
        &mut self,
        receiver_id: AccountId,
        token_id: TokenId,
        approval_id: Option<u64>,
        memo: Option<String>,
        msg: String,
    ) -> PromiseOrValue<bool>;
    fn nft_token(&self, token_id: TokenId) -> Option<Token>;
}
Expand description

Used for all non-fungible tokens. The specification for the core non-fungible token standard lays out the reasoning for each method. It’s important to check out NonFungibleTokenReceiver and NonFungibleTokenResolver to understand how the cross-contract call work.

§Examples

use near_sdk::{PanicOnDefault, AccountId, PromiseOrValue, near};
use near_contract_standards::non_fungible_token::{core::NonFungibleTokenCore, NonFungibleToken, TokenId, Token};

#[near(contract_state)]
#[derive(PanicOnDefault)]
pub struct Contract {
   tokens: NonFungibleToken,
}
#[near]
impl NonFungibleTokenCore for Contract {
    #[payable]
   fn nft_transfer(&mut self, receiver_id: AccountId, token_id: TokenId, approval_id: Option<u64>, memo: Option<String>) {
       self.tokens.nft_transfer(receiver_id, token_id, approval_id, memo);
   }

   #[payable]
   fn nft_transfer_call(&mut self, receiver_id: AccountId, token_id: TokenId, approval_id: Option<u64>, memo: Option<String>, msg: String) -> PromiseOrValue<bool> {
       self.tokens.nft_transfer_call(receiver_id, token_id, approval_id, memo, msg)
   }

   fn nft_token(&self, token_id: TokenId) -> Option<Token> {
       self.tokens.nft_token(token_id)
   }
}

Required Methods§

Source

fn nft_transfer( &mut self, receiver_id: AccountId, token_id: TokenId, approval_id: Option<u64>, memo: Option<String>, )

Simple transfer. Transfer a given token_id from current owner to receiver_id.

Requirements

Arguments:

  • receiver_id: the valid NEAR account receiving the token
  • token_id: the token to transfer
  • approval_id: expected approval ID. A number smaller than 2^53, and therefore representable as JSON. See Approval Management standard for full explanation.
  • memo (optional): for use cases that may benefit from indexing or providing information for a transfer
Source

fn nft_transfer_call( &mut self, receiver_id: AccountId, token_id: TokenId, approval_id: Option<u64>, memo: Option<String>, msg: String, ) -> PromiseOrValue<bool>

Transfer token and call a method on a receiver contract. A successful workflow will end in a success execution outcome to the callback on the NFT contract at the method nft_resolve_transfer.

You can think of this as being similar to attaching native NEAR tokens to a function call. It allows you to attach any Non-Fungible Token in a call to a receiver contract.

Requirements:

  • Caller of the method must attach a deposit of 1 yoctoⓃ for security purposes
  • Contract MUST panic if called by someone other than token owner or, if using Approval Management, one of the approved accounts
  • The receiving contract must implement ft_on_transfer according to the standard. If it does not, FT contract’s ft_resolve_transfer MUST deal with the resulting failed cross-contract call and roll back the transfer.
  • Contract MUST implement the behavior described in ft_resolve_transfer
  • approval_id is for use with Approval Management extension, see that document for full explanation.
  • If using Approval Management, contract MUST nullify approved accounts on successful transfer.

Arguments:

  • receiver_id: the valid NEAR account receiving the token.
  • token_id: the token to send.
  • approval_id: expected approval ID. A number smaller than 2^53, and therefore representable as JSON. See Approval Management standard for full explanation.
  • memo (optional): for use cases that may benefit from indexing or providing information for a transfer.
  • msg: specifies information needed by the receiving contract in order to properly handle the transfer. Can indicate both a function to call and the parameters to pass to that function.
Source

fn nft_token(&self, token_id: TokenId) -> Option<Token>

Returns the token with the given token_id or null if no such token.

Implementors§