IERC721Metadata

Git Source

See https://eips.ethereum.org/EIPS/eip-721 Note: the ERC-165 identifier for this interface is 0x5b5e139f.

Functions

balanceOf

Count all NFTs assigned to an owner

NFTs assigned to the zero address are considered invalid, and this function throws for queries about the zero address.

function balanceOf(address _owner) external view returns (uint256);

Parameters

NameTypeDescription
_owneraddressAn address for whom to query the balance

Returns

NameTypeDescription
<none>uint256The number of NFTs owned by _owner, possibly zero

ownerOf

Find the owner of an NFT

NFTs assigned to zero address are considered invalid, and queries about them do throw.

function ownerOf(uint256 _tokenId) external view returns (address);

Parameters

NameTypeDescription
_tokenIduint256The identifier for an NFT

Returns

NameTypeDescription
<none>addressThe address of the owner of the NFT

safeTransferFrom

Transfers the ownership of an NFT from one address to another address

Throws unless msg.sender is the current owner, an authorized operator, or the approved address for this NFT. Throws if _from is not the current owner. Throws if _to is the zero address. Throws if _tokenId is not a valid NFT. When transfer is complete, this function checks if _to is a smart contract (code size > 0). If so, it calls onERC721Received on _to and throws if the return value is not bytes4(keccak256("onERC721Received(address,address,uint256,bytes)")).

function safeTransferFrom(address _from, address _to, uint256 _tokenId, bytes calldata data) external payable;

Parameters

NameTypeDescription
_fromaddressThe current owner of the NFT
_toaddressThe new owner
_tokenIduint256The NFT to transfer
databytesAdditional data with no specified format, sent in call to _to

safeTransferFrom

Transfers the ownership of an NFT from one address to another address

This works identically to the other function with an extra data parameter, except this function just sets data to "".

function safeTransferFrom(address _from, address _to, uint256 _tokenId) external payable;

Parameters

NameTypeDescription
_fromaddressThe current owner of the NFT
_toaddressThe new owner
_tokenIduint256The NFT to transfer

transferFrom

Transfer ownership of an NFT -- THE CALLER IS RESPONSIBLE TO CONFIRM THAT _to IS CAPABLE OF RECEIVING NFTS OR ELSE THEY MAY BE PERMANENTLY LOST

Throws unless msg.sender is the current owner, an authorized operator, or the approved address for this NFT. Throws if _from is not the current owner. Throws if _to is the zero address. Throws if _tokenId is not a valid NFT.

function transferFrom(address _from, address _to, uint256 _tokenId) external payable;

Parameters

NameTypeDescription
_fromaddressThe current owner of the NFT
_toaddressThe new owner
_tokenIduint256The NFT to transfer

approve

Change or reaffirm the approved address for an NFT

The zero address indicates there is no approved address. Throws unless msg.sender is the current NFT owner, or an authorized operator of the current owner.

function approve(address _approved, uint256 _tokenId) external payable;

Parameters

NameTypeDescription
_approvedaddressThe new approved NFT controller
_tokenIduint256The NFT to approve

setApprovalForAll

Enable or disable approval for a third party ("operator") to manage all of msg.sender's assets

Emits the ApprovalForAll event. The contract MUST allow multiple operators per owner.

function setApprovalForAll(address _operator, bool _approved) external;

Parameters

NameTypeDescription
_operatoraddressAddress to add to the set of authorized operators
_approvedboolTrue if the operator is approved, false to revoke approval

getApproved

Get the approved address for a single NFT

Throws if _tokenId is not a valid NFT.

function getApproved(uint256 _tokenId) external view returns (address);

Parameters

NameTypeDescription
_tokenIduint256The NFT to find the approved address for

Returns

NameTypeDescription
<none>addressThe approved address for this NFT, or the zero address if there is none

isApprovedForAll

Query if an address is an authorized operator for another address

function isApprovedForAll(address _owner, address _operator) external view returns (bool);

Parameters

NameTypeDescription
_owneraddressThe address that owns the NFTs
_operatoraddressThe address that acts on behalf of the owner

Returns

NameTypeDescription
<none>boolTrue if _operator is an approved operator for _owner, false otherwise

name

A descriptive name for a collection of NFTs in this contract

function name() external view returns (string memory);

symbol

An abbreviated name for NFTs in this contract

function symbol() external view returns (string memory);

tokenURI

A distinct Uniform Resource Identifier (URI) for a given asset.

Throws if _tokenId is not a valid NFT. URIs are defined in RFC 3986. The URI may point to a JSON file that conforms to the "ERC721 Metadata JSON Schema".

function tokenURI(uint256) external view returns (string memory);

Events

Transfer

This emits when ownership of any NFT changes by any mechanism. This event emits when NFTs are created (from == 0) and destroyed (to == 0). Exception: during contract creation, any number of NFTs may be created and assigned without emitting Transfer. At the time of any transfer, the approved address for that NFT (if any) is reset to none.

event Transfer(address indexed _from, address indexed _to, uint256 indexed _tokenId);

Approval

This emits when the approved address for an NFT is changed or reaffirmed. The zero address indicates there is no approved address. When a Transfer event emits, this also indicates that the approved address for that NFT (if any) is reset to none.

event Approval(address indexed _owner, address indexed _approved, uint256 indexed _tokenId);

ApprovalForAll

This emits when an operator is enabled or disabled for an owner. The operator can manage all NFTs of the owner.

event ApprovalForAll(address indexed _owner, address indexed _operator, bool _approved);