Common
Smart contract common utilities and implementations
Functionality that is common to multiple token standards.
ERC2981: NFT Royalties compatible with both ERC-721 and ERC-1155.- For ERC-721 consider
ERC721Royaltywhich clears the royalty information from storage on burn.
- For ERC-721 consider
Contracts
import "@openzeppelin/contracts/token/common/ERC2981.sol";Implementation of the NFT Royalty Standard, a standardized way to retrieve royalty payment information.
Royalty information can be specified globally for all token ids via ERC2981._setDefaultRoyalty, and/or individually for
specific token ids via ERC2981._setTokenRoyalty. The latter takes precedence over the first.
Royalty is specified as a fraction of sale price. ERC2981._feeDenominator is overridable but defaults to 10000, meaning the
fee is specified in basis points by default.
ERC-2981 only specifies a way to signal royalty information and does not enforce its payment. See
Rationale in the ERC. Marketplaces are expected to voluntarily pay royalties together with sales, but note that this standard is not yet widely supported.
Functions
Errors
supportsInterface(bytes4 interfaceId) → bool
public
#Returns true if this contract implements the interface defined by
interfaceId. See the corresponding
ERC section
to learn more about how these ids are created.
This function call must use less than 30 000 gas.
royaltyInfo(uint256 tokenId, uint256 salePrice) → address receiver, uint256 amount
public
#Returns how much royalty is owed and to whom, based on a sale price that may be denominated in any unit of exchange. The royalty amount is denominated and should be paid in that same unit of exchange.
NOTE: ERC-2981 allows setting the royalty to 100% of the price. In that case all the price would be sent to the royalty receiver and 0 tokens to the seller. Contracts dealing with royalty should consider empty transfers.
_feeDenominator() → uint96
internal
#The denominator with which to interpret the fee set in ERC2981._setTokenRoyalty and ERC2981._setDefaultRoyalty as a
fraction of the sale price. Defaults to 10000 so fees are expressed in basis points, but may be customized by an
override.
_setDefaultRoyalty(address receiver, uint96 feeNumerator)
internal
#Sets the royalty information that all ids in this contract will default to.
Requirements:
receivercannot be the zero address.feeNumeratorcannot be greater than the fee denominator.
_deleteDefaultRoyalty()
internal
#Removes default royalty information.
_setTokenRoyalty(uint256 tokenId, address receiver, uint96 feeNumerator)
internal
#Sets the royalty information for a specific token id, overriding the global default.
Requirements:
receivercannot be the zero address.feeNumeratorcannot be greater than the fee denominator.
_resetTokenRoyalty(uint256 tokenId)
internal
#Resets royalty information for the token id back to the global default.
ERC2981InvalidDefaultRoyalty(uint256 numerator, uint256 denominator)
error
#The default royalty set is invalid (eg. (numerator / denominator) >= 1).
ERC2981InvalidDefaultRoyaltyReceiver(address receiver)
error
#The default royalty receiver is invalid.
ERC2981InvalidTokenRoyalty(uint256 tokenId, uint256 numerator, uint256 denominator)
error
#The royalty set for a specific tokenId is invalid (eg. (numerator / denominator) >= 1).
ERC2981InvalidTokenRoyaltyReceiver(uint256 tokenId, address receiver)
error
#The royalty receiver for tokenId is invalid.