IERC721Metadata
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
| Name | Type | Description |
|---|---|---|
_owner | address | An address for whom to query the balance |
Returns
| Name | Type | Description |
|---|---|---|
<none> | uint256 | The 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
| Name | Type | Description |
|---|---|---|
_tokenId | uint256 | The identifier for an NFT |
Returns
| Name | Type | Description |
|---|---|---|
<none> | address | The 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
| Name | Type | Description |
|---|---|---|
_from | address | The current owner of the NFT |
_to | address | The new owner |
_tokenId | uint256 | The NFT to transfer |
data | bytes | Additional 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
| Name | Type | Description |
|---|---|---|
_from | address | The current owner of the NFT |
_to | address | The new owner |
_tokenId | uint256 | The 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
| Name | Type | Description |
|---|---|---|
_from | address | The current owner of the NFT |
_to | address | The new owner |
_tokenId | uint256 | The 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
| Name | Type | Description |
|---|---|---|
_approved | address | The new approved NFT controller |
_tokenId | uint256 | The 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
| Name | Type | Description |
|---|---|---|
_operator | address | Address to add to the set of authorized operators |
_approved | bool | True 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
| Name | Type | Description |
|---|---|---|
_tokenId | uint256 | The NFT to find the approved address for |
Returns
| Name | Type | Description |
|---|---|---|
<none> | address | The 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
| Name | Type | Description |
|---|---|---|
_owner | address | The address that owns the NFTs |
_operator | address | The address that acts on behalf of the owner |
Returns
| Name | Type | Description |
|---|---|---|
<none> | bool | True 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);