DCIPs/assets/eip-6059/contracts/NestableToken.sol

1469 lines
57 KiB
Solidity

// SPDX-License-Identifier: CC0-1.0
//Generally all interactions should propagate downstream
pragma solidity ^0.8.16;
import "./IERC6059.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/IERC721Metadata.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721.sol";
import "@openzeppelin/contracts/token/ERC721/IERC721Receiver.sol";
import "@openzeppelin/contracts/utils/Address.sol";
import "@openzeppelin/contracts/utils/Context.sol";
import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
error ChildAlreadyExists();
error ChildIndexOutOfRange();
error ERC721AddressZeroIsNotaValidOwner();
error ERC721ApprovalToCurrentOwner();
error ERC721ApproveCallerIsNotOwnerNorApprovedForAll();
error ERC721ApproveToCaller();
error ERC721InvalidTokenId();
error ERC721MintToTheZeroAddress();
error ERC721NotApprovedOrOwner();
error ERC721TokenAlreadyMinted();
error ERC721TransferFromIncorrectOwner();
error ERC721TransferToNonReceiverImplementer();
error ERC721TransferToTheZeroAddress();
error IdZeroForbidden();
error IsNotContract();
error MaxPendingChildrenReached();
error MaxRecursiveBurnsReached(address childContract, uint256 childId);
error MintToNonNestableImplementer();
error NestableTooDeep();
error NestableTransferToDescendant();
error NestableTransferToNonNestableImplementer();
error NestableTransferToSelf();
error NotApprovedOrDirectOwner();
error PendingChildIndexOutOfRange();
error UnexpectedChildId();
error UnexpectedNumberOfChildren();
/**
* @title NestableToken
* @author RMRK team
* @notice Smart contract of the Nestable module.
* @dev This contract is hierarchy agnostic and can support an arbitrary number of nested levels up and down, as long as
* gas limits allow it.
*/
contract NestableToken is Context, IERC165, IERC721, IERC6059 {
using Address for address;
uint256 private constant _MAX_LEVELS_TO_CHECK_FOR_INHERITANCE_LOOP = 100;
// Mapping owner address to token count
mapping(address => uint256) private _balances;
// Mapping from token ID to approver address to approved address
// The approver is necessary so approvals are invalidated for nested children on transfer
// WARNING: If a child NFT returns to a previous root owner, old permissions would be active again
mapping(uint256 => mapping(address => address)) private _tokenApprovals;
// Mapping from owner to operator approvals
mapping(address => mapping(address => bool)) private _operatorApprovals;
// ------------------- NESTABLE --------------
// Mapping from token ID to DirectOwner struct
mapping(uint256 => DirectOwner) private _directOwners;
// Mapping of tokenId to array of active children structs
mapping(uint256 => Child[]) private _activeChildren;
// Mapping of tokenId to array of pending children structs
mapping(uint256 => Child[]) private _pendingChildren;
// Mapping of child token address to child token ID to whether they are pending or active on any token
// We might have a first extra mapping from token ID, but since the same child cannot be nested into multiple tokens
// we can strip it for size/gas savings.
mapping(address => mapping(uint256 => uint256)) private _childIsInActive;
// -------------------------- MODIFIERS ----------------------------
/**
* @notice Used to verify that the caller is either the owner of the token or approved to manage it by its owner.
* @dev If the caller is not the owner of the token or approved to manage it by its owner, the execution will be
* reverted.
* @param tokenId ID of the token to check
*/
function _onlyApprovedOrOwner(uint256 tokenId) private view {
if (!_isApprovedOrOwner(_msgSender(), tokenId))
revert ERC721NotApprovedOrOwner();
}
/**
* @notice Used to verify that the caller is either the owner of the token or approved to manage it by its owner.
* @param tokenId ID of the token to check
*/
modifier onlyApprovedOrOwner(uint256 tokenId) {
_onlyApprovedOrOwner(tokenId);
_;
}
/**
* @notice Used to verify that the caller is approved to manage the given token or it its direct owner.
* @dev This does not delegate to ownerOf, which returns the root owner, but rater uses an owner from DirectOwner
* struct.
* @dev The execution is reverted if the caller is not immediate owner or approved to manage the given token.
* @dev Used for parent-scoped transfers.
* @param tokenId ID of the token to check.
*/
function _onlyApprovedOrDirectOwner(uint256 tokenId) private view {
if (!_isApprovedOrDirectOwner(_msgSender(), tokenId))
revert NotApprovedOrDirectOwner();
}
/**
* @notice Used to verify that the caller is approved to manage the given token or is its direct owner.
* @param tokenId ID of the token to check
*/
modifier onlyApprovedOrDirectOwner(uint256 tokenId) {
_onlyApprovedOrDirectOwner(tokenId);
_;
}
// ------------------------------- ERC721 ---------------------------------
/**
* @inheritdoc IERC165
*/
function supportsInterface(
bytes4 interfaceId
) public view virtual returns (bool) {
return
interfaceId == type(IERC165).interfaceId ||
interfaceId == type(IERC721).interfaceId ||
interfaceId == type(IERC721Metadata).interfaceId ||
interfaceId == type(IERC6059).interfaceId;
}
/**
* @inheritdoc IERC721
*/
function balanceOf(address owner) public view virtual returns (uint256) {
if (owner == address(0)) revert ERC721AddressZeroIsNotaValidOwner();
return _balances[owner];
}
////////////////////////////////////////
// TRANSFERS
////////////////////////////////////////
/**
* @inheritdoc IERC721
*/
function transferFrom(
address from,
address to,
uint256 tokenId
) public virtual onlyApprovedOrDirectOwner(tokenId) {
_transfer(from, to, tokenId);
}
/**
* @inheritdoc IERC721
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId
) public virtual {
safeTransferFrom(from, to, tokenId, "");
}
/**
* @inheritdoc IERC721
*/
function safeTransferFrom(
address from,
address to,
uint256 tokenId,
bytes memory data
) public virtual onlyApprovedOrDirectOwner(tokenId) {
_safeTransfer(from, to, tokenId, data);
}
/**
* @notice Used to transfer the token into another token.
* @dev The destination token MUST NOT be a child token of the token being transferred or one of its downstream
* child tokens.
* @param from Address of the direct owner of the token to be transferred
* @param to Address of the receiving token's collection smart contract
* @param tokenId ID of the token being transferred
* @param destinationId ID of the token to receive the token being transferred
*/
function nestTransferFrom(
address from,
address to,
uint256 tokenId,
uint256 destinationId,
bytes memory data
) public virtual onlyApprovedOrDirectOwner(tokenId) {
_nestTransfer(from, to, tokenId, destinationId, data);
}
/**
* @notice Used to safely transfer the token form `from` to `to`.
* @dev The function checks that contract recipients are aware of the ERC721 protocol to prevent tokens from being
* forever locked.
* @dev This internal function is equivalent to {safeTransferFrom}, and can be used to e.g. implement alternative
* mechanisms to perform token transfer, such as signature-based.
* @dev Requirements:
*
* - `from` cannot be the zero address.
* - `to` cannot be the zero address.
* - `tokenId` token must exist and be owned by `from`.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
* @dev Emits a {Transfer} event.
* @param from Address of the account currently owning the given token
* @param to Address to transfer the token to
* @param tokenId ID of the token to transfer
* @param data Additional data with no specified format, sent in call to `to`
*/
function _safeTransfer(
address from,
address to,
uint256 tokenId,
bytes memory data
) internal virtual {
_transfer(from, to, tokenId);
if (!_checkOnERC721Received(from, to, tokenId, data))
revert ERC721TransferToNonReceiverImplementer();
}
/**
* @notice Used to transfer the token from `from` to `to`.
* @dev As opposed to {transferFrom}, this imposes no restrictions on msg.sender.
* @dev Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` token must be owned by `from`.
* @dev Emits a {Transfer} event.
* @param from Address of the account currently owning the given token
* @param to Address to transfer the token to
* @param tokenId ID of the token to transfer
*/
function _transfer(
address from,
address to,
uint256 tokenId
) internal virtual {
(address immediateOwner, uint256 parentId, ) = directOwnerOf(tokenId);
if (immediateOwner != from) revert ERC721TransferFromIncorrectOwner();
if (to == address(0)) revert ERC721TransferToTheZeroAddress();
_beforeTokenTransfer(from, to, tokenId);
_beforeNestedTokenTransfer(immediateOwner, to, parentId, 0, tokenId);
_balances[from] -= 1;
_updateOwnerAndClearApprovals(tokenId, 0, to, false);
_balances[to] += 1;
emit Transfer(from, to, tokenId);
emit NestTransfer(immediateOwner, to, parentId, 0, tokenId);
_afterTokenTransfer(from, to, tokenId);
_afterNestedTokenTransfer(immediateOwner, to, parentId, 0, tokenId);
}
/**
* @notice Used to transfer a token into another token.
* @dev Attempting to nest a token into `0x0` address will result in reverted transaction.
* @dev Attempting to nest a token into itself will result in reverted transaction.
* @param from Address of the account currently owning the given token
* @param to Address of the receiving token's collection smart contract
* @param tokenId ID of the token to transfer
* @param destinationId ID of the token receiving the given token
* @param data Additional data with no specified format, sent in the addChild call
*/
function _nestTransfer(
address from,
address to,
uint256 tokenId,
uint256 destinationId,
bytes memory data
) internal virtual {
(address immediateOwner, uint256 parentId, ) = directOwnerOf(tokenId);
if (immediateOwner != from) revert ERC721TransferFromIncorrectOwner();
if (to == address(0)) revert ERC721TransferToTheZeroAddress();
if (to == address(this) && tokenId == destinationId)
revert NestableTransferToSelf();
// Destination contract checks:
// It seems redundant, but otherwise it would revert with no error
if (!to.isContract()) revert IsNotContract();
if (!IERC165(to).supportsInterface(type(IERC6059).interfaceId))
revert NestableTransferToNonNestableImplementer();
_checkForInheritanceLoop(tokenId, to, destinationId);
_beforeTokenTransfer(from, to, tokenId);
_beforeNestedTokenTransfer(
immediateOwner,
to,
parentId,
destinationId,
tokenId
);
_balances[from] -= 1;
_updateOwnerAndClearApprovals(tokenId, destinationId, to, true);
_balances[to] += 1;
// Sending to NFT:
_sendToNFT(immediateOwner, to, parentId, destinationId, tokenId, data);
}
/**
* @notice Used to send a token to another token.
* @dev If the token being sent is currently owned by an externally owned account, the `parentId` should equal `0`.
* @dev Emits {Transfer} event.
* @dev Emits {NestTransfer} event.
* @param from Address from which the token is being sent
* @param to Address of the collection smart contract of the token to receive the given token
* @param parentId ID of the current parent token of the token being sent
* @param destinationId ID of the tokento receive the token being sent
* @param tokenId ID of the token being sent
* @param data Additional data with no specified format, sent in the addChild call
*/
function _sendToNFT(
address from,
address to,
uint256 parentId,
uint256 destinationId,
uint256 tokenId,
bytes memory data
) private {
IERC6059 destContract = IERC6059(to);
destContract.addChild(destinationId, tokenId, data);
_afterTokenTransfer(from, to, tokenId);
_afterNestedTokenTransfer(from, to, parentId, destinationId, tokenId);
emit Transfer(from, to, tokenId);
emit NestTransfer(from, to, parentId, destinationId, tokenId);
}
/**
* @notice Used to check if nesting a given token into a specified token would create an inheritance loop.
* @dev If a loop would occur, the tokens would be unmanageable, so the execution is reverted if one is detected.
* @dev The check for inheritance loop is bounded to guard against too much gas being consumed.
* @param currentId ID of the token that would be nested
* @param targetContract Address of the collection smart contract of the token into which the given token would be
* nested
* @param targetId ID of the token into which the given token would be nested
*/
function _checkForInheritanceLoop(
uint256 currentId,
address targetContract,
uint256 targetId
) private view {
for (uint256 i; i < _MAX_LEVELS_TO_CHECK_FOR_INHERITANCE_LOOP; ) {
(
address nextOwner,
uint256 nextOwnerTokenId,
bool isNft
) = IERC6059(targetContract).directOwnerOf(targetId);
// If there's a final address, we're good. There's no loop.
if (!isNft) {
return;
}
// Ff the current nft is an ancestor at some point, there is an inheritance loop
if (nextOwner == address(this) && nextOwnerTokenId == currentId) {
revert NestableTransferToDescendant();
}
// We reuse the parameters to save some contract size
targetContract = nextOwner;
targetId = nextOwnerTokenId;
unchecked {
++i;
}
}
revert NestableTooDeep();
}
////////////////////////////////////////
// MINTING
////////////////////////////////////////
/**
* @notice Used to safely mint a token to a specified address.
* @dev Requirements:
*
* - `tokenId` must not exist.
* - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
* @dev Emits a {Transfer} event.
* @param to Address to which to safely mint the gven token
* @param tokenId ID of the token to mint to the specified address
*/
function _safeMint(address to, uint256 tokenId) internal virtual {
_safeMint(to, tokenId, "");
}
/**
* @notice Used to safely mint the token to the specified address while passing the additional data to contract
* recipients.
* @param to Address to which to mint the token
* @param tokenId ID of the token to mint
* @param data Additional data to send with the tokens
*/
function _safeMint(
address to,
uint256 tokenId,
bytes memory data
) internal virtual {
_mint(to, tokenId);
if (!_checkOnERC721Received(address(0), to, tokenId, data))
revert ERC721TransferToNonReceiverImplementer();
}
/**
* @notice Used to mint a specified token to a given address.
* @dev WARNING: Usage of this method is discouraged, use {_safeMint} whenever possible.
* @dev Requirements:
*
* - `tokenId` must not exist.
* - `to` cannot be the zero address.
* @dev Emits a {Transfer} event.
* @param to Address to mint the token to
* @param tokenId ID of the token to mint
*/
function _mint(address to, uint256 tokenId) internal virtual {
_innerMint(to, tokenId, 0);
emit Transfer(address(0), to, tokenId);
emit NestTransfer(address(0), to, 0, 0, tokenId);
_afterTokenTransfer(address(0), to, tokenId);
_afterNestedTokenTransfer(address(0), to, 0, 0, tokenId);
}
/**
* @notice Used to mint a child token to a given parent token.
* @param to Address of the collection smart contract of the token into which to mint the child token
* @param tokenId ID of the token to mint
* @param destinationId ID of the token into which to mint the new child token
* @param data Additional data with no specified format, sent in the addChild call
*/
function _nestMint(
address to,
uint256 tokenId,
uint256 destinationId,
bytes memory data
) internal virtual {
// It seems redundant, but otherwise it would revert with no error
if (!to.isContract()) revert IsNotContract();
if (!IERC165(to).supportsInterface(type(IERC6059).interfaceId))
revert MintToNonNestableImplementer();
_innerMint(to, tokenId, destinationId);
_sendToNFT(address(0), to, 0, destinationId, tokenId, data);
}
/**
* @notice Used to mint a child token into a given parent token.
* @dev Requirements:
*
* - `to` cannot be the zero address.
* - `tokenId` must not exist.
* - `tokenId` must not be `0`.
* @param to Address of the collection smart contract of the token into which to mint the child token
* @param tokenId ID of the token to mint
* @param destinationId ID of the token into which to mint the new token
*/
function _innerMint(
address to,
uint256 tokenId,
uint256 destinationId
) private {
if (to == address(0)) revert ERC721MintToTheZeroAddress();
if (_exists(tokenId)) revert ERC721TokenAlreadyMinted();
if (tokenId == 0) revert IdZeroForbidden();
_beforeTokenTransfer(address(0), to, tokenId);
_beforeNestedTokenTransfer(address(0), to, 0, destinationId, tokenId);
_balances[to] += 1;
_directOwners[tokenId] = DirectOwner({
ownerAddress: to,
tokenId: destinationId,
isNft: destinationId != 0
});
}
////////////////////////////////////////
// Ownership
////////////////////////////////////////
/**
* @notice Used to retrieve the root owner of the given token.
* @dev Root owner is always the externally owned account.
* @dev If the given token is owned by another token, it will recursively query the parent tokens until reaching the
* root owner.
* @param tokenId ID of the token for which the root owner is being retrieved
* @return address Address of the root owner of the given token
*/
function ownerOf(
uint256 tokenId
) public view virtual override(IERC6059, IERC721) returns (address) {
(address owner, uint256 ownerTokenId, bool isNft) = directOwnerOf(
tokenId
);
if (isNft) {
owner = IERC6059(owner).ownerOf(ownerTokenId);
}
return owner;
}
/**
* @notice Used to retrieve the immediate owner of the given token.
* @dev In the event the NFT is owned by an externally owned account, `tokenId` will be `0` and `isNft` will be
* `false`.
* @param tokenId ID of the token for which the immediate owner is being retrieved
* @return address Address of the immediate owner. If the token is owned by an externally owned account, its address
* will be returned. If the token is owned by another token, the parent token's collection smart contract address
* is returned
* @return uint256 Token ID of the immediate owner. If the immediate owner is an externally owned account, the value
* should be `0`
* @return bool A boolean value signifying whether the immediate owner is a token (`true`) or not (`false`)
*/
function directOwnerOf(
uint256 tokenId
) public view virtual returns (address, uint256, bool) {
DirectOwner memory owner = _directOwners[tokenId];
if (owner.ownerAddress == address(0)) revert ERC721InvalidTokenId();
return (owner.ownerAddress, owner.tokenId, owner.isNft);
}
////////////////////////////////////////
// BURNING
////////////////////////////////////////
/**
* @notice Used to burn a given token.
* @param tokenId ID of the token to burn
*/
function burn(uint256 tokenId) public virtual {
burn(tokenId, 0);
}
/**
* @notice Used to burn a token.
* @dev When a token is burned, its children are recursively burned as well.
* @dev The approvals are cleared when the token is burned.
* @dev Requirements:
*
* - `tokenId` must exist.
* @dev Emits a {Transfer} event.
* @param tokenId ID of the token to burn
* @param maxChildrenBurns Maximum children to recursively burn
* @return uint256 The number of recursive burns it took to burn all of the children
*/
function burn(
uint256 tokenId,
uint256 maxChildrenBurns
) public virtual onlyApprovedOrDirectOwner(tokenId) returns (uint256) {
return _burn(tokenId, maxChildrenBurns);
}
/**
* @notice Used to burn a token.
* @dev When a token is burned, its children are recursively burned as well.
* @dev The approvals are cleared when the token is burned.
* @dev Requirements:
*
* - `tokenId` must exist.
* @dev Emits a {Transfer} event.
* @dev Emits a {NestTransfer} event.
* @param tokenId ID of the token to burn
* @param maxChildrenBurns Maximum children to recursively burn
* @return uint256 The number of recursive burns it took to burn all of the children
*/
function _burn(
uint256 tokenId,
uint256 maxChildrenBurns
) internal virtual returns (uint256) {
(address immediateOwner, uint256 parentId, ) = directOwnerOf(tokenId);
address owner = ownerOf(tokenId);
_balances[immediateOwner] -= 1;
_beforeTokenTransfer(owner, address(0), tokenId);
_beforeNestedTokenTransfer(
immediateOwner,
address(0),
parentId,
0,
tokenId
);
_approve(address(0), tokenId);
_cleanApprovals(tokenId);
Child[] memory children = childrenOf(tokenId);
delete _activeChildren[tokenId];
delete _pendingChildren[tokenId];
delete _tokenApprovals[tokenId][owner];
uint256 pendingRecursiveBurns;
uint256 totalChildBurns;
uint256 length = children.length; //gas savings
for (uint256 i; i < length; ) {
if (totalChildBurns >= maxChildrenBurns)
revert MaxRecursiveBurnsReached(
children[i].contractAddress,
children[i].tokenId
);
delete _childIsInActive[children[i].contractAddress][
children[i].tokenId
];
unchecked {
// At this point we know pendingRecursiveBurns must be at least 1
pendingRecursiveBurns = maxChildrenBurns - totalChildBurns;
}
// We substract one to the next level to count for the token being burned, then add it again on returns
// This is to allow the behavior of 0 recursive burns meaning only the current token is deleted.
totalChildBurns +=
IERC6059(children[i].contractAddress).burn(
children[i].tokenId,
pendingRecursiveBurns - 1
) +
1;
unchecked {
++i;
}
}
// Can't remove before burning child since child will call back to get root owner
delete _directOwners[tokenId];
_afterTokenTransfer(owner, address(0), tokenId);
_afterNestedTokenTransfer(
immediateOwner,
address(0),
parentId,
0,
tokenId
);
emit Transfer(owner, address(0), tokenId);
emit NestTransfer(immediateOwner, address(0), parentId, 0, tokenId);
return totalChildBurns;
}
////////////////////////////////////////
// APPROVALS
////////////////////////////////////////
/**
* @inheritdoc IERC721
*/
function approve(address to, uint256 tokenId) public virtual {
address owner = ownerOf(tokenId);
if (to == owner) revert ERC721ApprovalToCurrentOwner();
if (_msgSender() != owner && !isApprovedForAll(owner, _msgSender()))
revert ERC721ApproveCallerIsNotOwnerNorApprovedForAll();
_approve(to, tokenId);
}
/**
* @inheritdoc IERC721
*/
function getApproved(
uint256 tokenId
) public view virtual returns (address) {
_requireMinted(tokenId);
return _tokenApprovals[tokenId][ownerOf(tokenId)];
}
/**
* @inheritdoc IERC721
*/
function setApprovalForAll(address operator, bool approved) public virtual {
if (_msgSender() == operator) revert ERC721ApproveToCaller();
_operatorApprovals[_msgSender()][operator] = approved;
emit ApprovalForAll(_msgSender(), operator, approved);
}
/**
* @inheritdoc IERC721
*/
function isApprovedForAll(
address owner,
address operator
) public view virtual returns (bool) {
return _operatorApprovals[owner][operator];
}
/**
* @notice Used to grant an approval to manage a given token.
* @dev Emits an {Approval} event.
* @param to Address to which the approval is being granted
* @param tokenId ID of the token for which the approval is being granted
*/
function _approve(address to, uint256 tokenId) internal virtual {
address owner = ownerOf(tokenId);
_tokenApprovals[tokenId][owner] = to;
emit Approval(owner, to, tokenId);
}
/**
* @notice Used to update the owner of the token and clear the approvals associated with the previous owner.
* @dev The `destinationId` should equal `0` if the new owner is an externally owned account.
* @param tokenId ID of the token being updated
* @param destinationId ID of the token to receive the given token
* @param to Address of account to receive the token
* @param isNft A boolean value signifying whether the new owner is a token (`true`) or externally owned account
* (`false`)
*/
function _updateOwnerAndClearApprovals(
uint256 tokenId,
uint256 destinationId,
address to,
bool isNft
) internal {
_directOwners[tokenId] = DirectOwner({
ownerAddress: to,
tokenId: destinationId,
isNft: isNft
});
// Clear approvals from the previous owner
_approve(address(0), tokenId);
_cleanApprovals(tokenId);
}
/**
* @notice Used to remove approvals for the current owner of the given token.
* @param tokenId ID of the token to clear the approvals for
*/
function _cleanApprovals(uint256 tokenId) internal virtual {}
////////////////////////////////////////
// UTILS
////////////////////////////////////////
/**
* @notice Used to check whether the given account is allowed to manage the given token.
* @dev Requirements:
*
* - `tokenId` must exist.
* @param spender Address that is being checked for approval
* @param tokenId ID of the token being checked
* @return bool The boolean value indicating whether the `spender` is approved to manage the given token
*/
function _isApprovedOrOwner(
address spender,
uint256 tokenId
) internal view virtual returns (bool) {
address owner = ownerOf(tokenId);
return (spender == owner ||
isApprovedForAll(owner, spender) ||
getApproved(tokenId) == spender);
}
/**
* @notice Used to check whether the account is approved to manage the token or its direct owner.
* @param spender Address that is being checked for approval or direct ownership
* @param tokenId ID of the token being checked
* @return bool The boolean value indicating whether the `spender` is approved to manage the given token or its
* direct owner
*/
function _isApprovedOrDirectOwner(
address spender,
uint256 tokenId
) internal view virtual returns (bool) {
(address owner, uint256 parentId, ) = directOwnerOf(tokenId);
// When the parent is an NFT, only it can do operations
if (parentId != 0) {
return (spender == owner);
}
// Otherwise, the owner or approved address can
return (spender == owner ||
isApprovedForAll(owner, spender) ||
getApproved(tokenId) == spender);
}
/**
* @notice Used to enforce that the given token has been minted.
* @dev Reverts if the `tokenId` has not been minted yet.
* @dev The validation checks whether the owner of a given token is a `0x0` address and considers it not minted if
* it is. This means that both tokens that haven't been minted yet as well as the ones that have already been
* burned will cause the transaction to be reverted.
* @param tokenId ID of the token to check
*/
function _requireMinted(uint256 tokenId) internal view virtual {
if (!_exists(tokenId)) revert ERC721InvalidTokenId();
}
/**
* @notice Used to check whether the given token exists.
* @dev Tokens start existing when they are minted (`_mint`) and stop existing when they are burned (`_burn`).
* @param tokenId ID of the token being checked
* @return bool The boolean value signifying whether the token exists
*/
function _exists(uint256 tokenId) internal view virtual returns (bool) {
return _directOwners[tokenId].ownerAddress != address(0);
}
/**
* @notice Used to invoke {IERC721Receiver-onERC721Received} on a target address.
* @dev The call is not executed if the target address is not a contract.
* @param from Address representing the previous owner of the given token
* @param to Yarget address that will receive the tokens
* @param tokenId ID of the token to be transferred
* @param data Optional data to send along with the call
* @return bool Boolean value signifying whether the call correctly returned the expected magic value
*/
function _checkOnERC721Received(
address from,
address to,
uint256 tokenId,
bytes memory data
) private returns (bool) {
if (to.isContract()) {
try
IERC721Receiver(to).onERC721Received(
_msgSender(),
from,
tokenId,
data
)
returns (bytes4 retval) {
return retval == IERC721Receiver.onERC721Received.selector;
} catch (bytes memory reason) {
if (reason.length == 0) {
revert ERC721TransferToNonReceiverImplementer();
} else {
/// @solidity memory-safe-assembly
assembly {
revert(add(32, reason), mload(reason))
}
}
}
} else {
return true;
}
}
////////////////////////////////////////
// CHILD MANAGEMENT PUBLIC
////////////////////////////////////////
/**
* @notice Used to add a child token to a given parent token.
* @dev This adds the iichild token into the given parent token's pending child tokens array.
* @dev You MUST NOT call this method directly. To add a a child to an NFT you must use either
* `nestTransfer`, `nestMint` or `transferChild` to the NFT.
* @dev Requirements:
*
* - `ownerOf` on the child contract must resolve to the called contract.
* - The pending array of the parent contract must not be full.
* @param parentId ID of the parent token to receive the new child token
* @param childId ID of the new proposed child token
* @param data Additional data with no specified format
*/
function addChild(
uint256 parentId,
uint256 childId,
bytes memory data
) public virtual {
_requireMinted(parentId);
address childAddress = _msgSender();
if (!childAddress.isContract()) revert IsNotContract();
Child memory child = Child({
contractAddress: childAddress,
tokenId: childId
});
_beforeAddChild(parentId, childAddress, childId);
uint256 length = pendingChildrenOf(parentId).length;
if (length < 128) {
_pendingChildren[parentId].push(child);
} else {
revert MaxPendingChildrenReached();
}
// Previous length matches the index for the new child
emit ChildProposed(parentId, length, childAddress, childId);
_afterAddChild(parentId, childAddress, childId);
}
/**
* @notice @notice Used to accept a pending child token for a given parent token.
* @dev This moves the child token from parent token's pending child tokens array into the active child tokens
* array.
* @param parentId ID of the parent token for which the child token is being accepted
* @param childIndex Index of a child tokem in the given parent's pending children array
* @param childAddress Address of the collection smart contract of the child token expected to be located at the
* specified index of the given parent token's pending children array
* @param childId ID of the child token expected to be located at the specified index of the given parent token's
* pending children array
*/
function acceptChild(
uint256 parentId,
uint256 childIndex,
address childAddress,
uint256 childId
) public virtual onlyApprovedOrOwner(parentId) {
_acceptChild(parentId, childIndex, childAddress, childId);
}
/**
* @notice Used to accept a pending child token for a given parent token.
* @dev This moves the child token from parent token's pending child tokens array into the active child tokens
* array.
* @dev Requirements:
*
* - `tokenId` must exist
* - `index` must be in range of the pending children array
* @param parentId ID of the parent token for which the child token is being accepted
* @param childIndex Index of a child tokem in the given parent's pending children array
* @param childAddress Address of the collection smart contract of the child token expected to be located at the
* specified index of the given parent token's pending children array
* @param childId ID of the child token expected to be located at the specified index of the given parent token's
* pending children array
*/
function _acceptChild(
uint256 parentId,
uint256 childIndex,
address childAddress,
uint256 childId
) internal virtual {
if (pendingChildrenOf(parentId).length <= childIndex)
revert PendingChildIndexOutOfRange();
Child memory child = pendingChildOf(parentId, childIndex);
_checkExpectedChild(child, childAddress, childId);
if (_childIsInActive[childAddress][childId] != 0)
revert ChildAlreadyExists();
_beforeAcceptChild(parentId, childIndex, childAddress, childId);
// Remove from pending:
_removeChildByIndex(_pendingChildren[parentId], childIndex);
// Add to active:
_activeChildren[parentId].push(child);
_childIsInActive[childAddress][childId] = 1; // We use 1 as true
emit ChildAccepted(parentId, childIndex, childAddress, childId);
_afterAcceptChild(parentId, childIndex, childAddress, childId);
}
/**
* @notice Used to reject all pending children of a given parent token.
* @dev Removes the children from the pending array mapping.
* @dev This does not update the ownership storage data on children. If necessary, ownership can be reclaimed by the
* rootOwner of the previous parent.
* @param tokenId ID of the parent token for which to reject all of the pending tokens
*/
function rejectAllChildren(uint256 tokenId, uint256 maxRejections) public virtual onlyApprovedOrOwner(tokenId) {
_rejectAllChildren(tokenId, maxRejections);
}
/**
* @notice Used to reject all pending children of a given parent token.
* @dev Removes the children from the pending array mapping.
* @dev This does not update the ownership storage data on children. If necessary, ownership can be reclaimed by the
* rootOwner of the previous parent.
* @dev Requirements:
*
* - `tokenId` must exist
* @param tokenId ID of the parent token for which to reject all of the pending tokens.
* @param maxRejections Maximum number of expected children to reject, used to prevent from
* rejecting children which arrive just before this operation.
*/
function _rejectAllChildren(uint256 tokenId, uint256 maxRejections)
internal
virtual
{
if (_pendingChildren[tokenId].length > maxRejections)
revert UnexpectedNumberOfChildren();
_beforeRejectAllChildren(tokenId);
delete _pendingChildren[tokenId];
emit AllChildrenRejected(tokenId);
_afterRejectAllChildren(tokenId);
}
/**
* @notice Used to transfer a child token from a given parent token.
* @param tokenId ID of the parent token from which the child token is being transferred
* @param to Address to which to transfer the token to
* @param destinationId ID of the token to receive this child token (MUST be 0 if the destination is not a token)
* @param childIndex Index of a token we are transferring, in the array it belongs to (can be either active array or
* pending array)
* @param childAddress Address of the child token's collection smart contract.
* @param childId ID of the child token in its own collection smart contract.
* @param isPending A boolean value indicating whether the child token being transferred is in the pending array of the
* parent token (`true`) or in the active array (`false`)
* @param data Additional data with no specified format, sent in call to `_to`
*/
function transferChild(
uint256 tokenId,
address to,
uint256 destinationId,
uint256 childIndex,
address childAddress,
uint256 childId,
bool isPending,
bytes memory data
) public virtual onlyApprovedOrOwner(tokenId) {
_transferChild(
tokenId,
to,
destinationId,
childIndex,
childAddress,
childId,
isPending,
data
);
}
/**
* @notice Used to transfer a child token from a given parent token.
* @dev When transferring a child token, the owner of the token is set to `to`, or is not updated in the event of `to`
* being the `0x0` address.
* @dev Requirements:
*
* - `tokenId` must exist.
* @dev Emits {ChildTransferred} event.
* @param tokenId ID of the parent token from which the child token is being transferred
* @param to Address to which to transfer the token to
* @param destinationId ID of the token to receive this child token (MUST be 0 if the destination is not a token)
* @param childIndex Index of a token we are transferring, in the array it belongs to (can be either active array or
* pending array)
* @param childAddress Address of the child token's collection smart contract.
* @param childId ID of the child token in its own collection smart contract.
* @param isPending A boolean value indicating whether the child token being transferred is in the pending array of the
* parent token (`true`) or in the active array (`false`)
* @param data Additional data with no specified format, sent in call to `_to`
*/
function _transferChild(
uint256 tokenId,
address to,
uint256 destinationId, // newParentId
uint256 childIndex,
address childAddress,
uint256 childId,
bool isPending,
bytes memory data
) internal virtual {
Child memory child;
if (isPending) {
child = pendingChildOf(tokenId, childIndex);
} else {
child = childOf(tokenId, childIndex);
}
_checkExpectedChild(child, childAddress, childId);
_beforeTransferChild(
tokenId,
childIndex,
childAddress,
childId,
isPending
);
if (isPending) {
_removeChildByIndex(_pendingChildren[tokenId], childIndex);
} else {
delete _childIsInActive[childAddress][childId];
_removeChildByIndex(_activeChildren[tokenId], childIndex);
}
if (to != address(0)) {
if (destinationId == 0) {
IERC721(childAddress).safeTransferFrom(
address(this),
to,
childId,
data
);
} else {
// Destination is an NFT
IERC6059(child.contractAddress).nestTransferFrom(
address(this),
to,
child.tokenId,
destinationId,
data
);
}
}
emit ChildTransferred(
tokenId,
childIndex,
childAddress,
childId,
isPending
);
_afterTransferChild(
tokenId,
childIndex,
childAddress,
childId,
isPending
);
}
function _checkExpectedChild(
Child memory child,
address expectedAddress,
uint256 expectedId
) private pure {
if (
expectedAddress != child.contractAddress ||
expectedId != child.tokenId
) revert UnexpectedChildId();
}
////////////////////////////////////////
// CHILD MANAGEMENT GETTERS
////////////////////////////////////////
/**
* @notice Used to retrieve the active child tokens of a given parent token.
* @dev Returns array of Child structs existing for parent token.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @param parentId ID of the parent token for which to retrieve the active child tokens
* @return struct[] An array of Child structs containing the parent token's active child tokens
*/
function childrenOf(
uint256 parentId
) public view virtual returns (Child[] memory) {
Child[] memory children = _activeChildren[parentId];
return children;
}
/**
* @notice Used to retrieve the pending child tokens of a given parent token.
* @dev Returns array of pending Child structs existing for given parent.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @param parentId ID of the parent token for which to retrieve the pending child tokens
* @return struct[] An array of Child structs containing the parent token's pending child tokens
*/
function pendingChildrenOf(
uint256 parentId
) public view virtual returns (Child[] memory) {
Child[] memory pendingChildren = _pendingChildren[parentId];
return pendingChildren;
}
/**
* @notice Used to retrieve a specific active child token for a given parent token.
* @dev Returns a single Child struct locating at `index` of parent token's active child tokens array.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @param parentId ID of the parent token for which the child is being retrieved
* @param index Index of the child token in the parent token's active child tokens array
* @return struct A Child struct containing data about the specified child
*/
function childOf(
uint256 parentId,
uint256 index
) public view virtual returns (Child memory) {
if (childrenOf(parentId).length <= index) revert ChildIndexOutOfRange();
Child memory child = _activeChildren[parentId][index];
return child;
}
/**
* @notice Used to retrieve a specific pending child token from a given parent token.
* @dev Returns a single Child struct locating at `index` of parent token's active child tokens array.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @param parentId ID of the parent token for which the pending child token is being retrieved
* @param index Index of the child token in the parent token's pending child tokens array
* @return struct A Child struct containting data about the specified child
*/
function pendingChildOf(
uint256 parentId,
uint256 index
) public view virtual returns (Child memory) {
if (pendingChildrenOf(parentId).length <= index)
revert PendingChildIndexOutOfRange();
Child memory child = _pendingChildren[parentId][index];
return child;
}
/**
* @notice Used to verify that the given child tokwn is included in an active array of a token.
* @param childAddress Address of the given token's collection smart contract
* @param childId ID of the child token being checked
* @return bool A boolean value signifying whether the given child token is included in an active child tokens array
* of a token (`true`) or not (`false`)
*/
function childIsInActive(
address childAddress,
uint256 childId
) public view virtual returns (bool) {
return _childIsInActive[childAddress][childId] != 0;
}
// HOOKS
/**
* @notice Hook that is called before any token transfer. This includes minting and burning.
* @dev Calling conditions:
*
* - When `from` and `to` are both non-zero, ``from``'s `tokenId` will be transferred to `to`.
* - When `from` is zero, `tokenId` will be minted to `to`.
* - When `to` is zero, ``from``'s `tokenId` will be burned.
* - `from` and `to` are never zero at the same time.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param from Address from which the token is being transferred
* @param to Address to which the token is being transferred
* @param tokenId ID of the token being transferred
*/
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual {}
/**
* @notice Hook that is called after any transfer of tokens. This includes minting and burning.
* @dev Calling conditions:
*
* - When `from` and `to` are both non-zero.
* - `from` and `to` are never zero at the same time.
*
* To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param from Address from which the token has been transferred
* @param to Address to which the token has been transferred
* @param tokenId ID of the token that has been transferred
*/
function _afterTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual {}
/**
* @notice Hook that is called before nested token transfer.
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param from Address from which the token is being transferred
* @param to Address to which the token is being transferred
* @param fromTokenId ID of the token from which the given token is being transferred
* @param toTokenId ID of the token to which the given token is being transferred
* @param tokenId ID of the token being transferred
*/
function _beforeNestedTokenTransfer(
address from,
address to,
uint256 fromTokenId,
uint256 toTokenId,
uint256 tokenId
) internal virtual {}
/**
* @notice Hook that is called after nested token transfer.
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param from Address from which the token was transferred
* @param to Address to which the token was transferred
* @param fromTokenId ID of the token from which the given token was transferred
* @param toTokenId ID of the token to which the given token was transferred
* @param tokenId ID of the token that was transferred
*/
function _afterNestedTokenTransfer(
address from,
address to,
uint256 fromTokenId,
uint256 toTokenId,
uint256 tokenId
) internal virtual {}
/**
* @notice Hook that is called before a child is added to the pending tokens array of a given token.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param tokenId ID of the token that will receive a new pending child token
* @param childAddress Address of the collection smart contract of the child token expected to be located at the
* specified index of the given parent token's pending children array
* @param childId ID of the child token expected to be located at the specified index of the given parent token's
* pending children array
*/
function _beforeAddChild(
uint256 tokenId,
address childAddress,
uint256 childId
) internal virtual {}
/**
* @notice Hook that is called after a child is added to the pending tokens array of a given token.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param tokenId ID of the token that has received a new pending child token
* @param childAddress Address of the collection smart contract of the child token expected to be located at the
* specified index of the given parent token's pending children array
* @param childId ID of the child token expected to be located at the specified index of the given parent token's
* pending children array
*/
function _afterAddChild(
uint256 tokenId,
address childAddress,
uint256 childId
) internal virtual {}
/**
* @notice Hook that is called before a child is accepted to the active tokens array of a given token.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param parentId ID of the token that will accept a pending child token
* @param childIndex Index of the child token to accept in the given parent token's pending children array
* @param childAddress Address of the collection smart contract of the child token expected to be located at the
* specified index of the given parent token's pending children array
* @param childId ID of the child token expected to be located at the specified index of the given parent token's
* pending children array
*/
function _beforeAcceptChild(
uint256 parentId,
uint256 childIndex,
address childAddress,
uint256 childId
) internal virtual {}
/**
* @notice Hook that is called after a child is accepted to the active tokens array of a given token.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param parentId ID of the token that has accepted a pending child token
* @param childIndex Index of the child token that was accpeted in the given parent token's pending children array
* @param childAddress Address of the collection smart contract of the child token that was expected to be located
* at the specified index of the given parent token's pending children array
* @param childId ID of the child token that was expected to be located at the specified index of the given parent
* token's pending children array
*/
function _afterAcceptChild(
uint256 parentId,
uint256 childIndex,
address childAddress,
uint256 childId
) internal virtual {}
/**
* @notice Hook that is called before a child is transferred from a given child token array of a given token.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param tokenId ID of the token that will transfer a child token
* @param childIndex Index of the child token that will be transferred from the given parent token's children array
* @param childAddress Address of the collection smart contract of the child token that is expected to be located
* at the specified index of the given parent token's children array
* @param childId ID of the child token that is expected to be located at the specified index of the given parent
* token's children array
* @param isPending A boolean value signifying whether the child token is being transferred from the pending child
* tokens array (`true`) or from the active child tokens array (`false`)
*/
function _beforeTransferChild(
uint256 tokenId,
uint256 childIndex,
address childAddress,
uint256 childId,
bool isPending
) internal virtual {}
/**
* @notice Hook that is called after a child is transferred from a given child token array of a given token.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param tokenId ID of the token that has transferred a child token
* @param childIndex Index of the child token that was transferred from the given parent token's children array
* @param childAddress Address of the collection smart contract of the child token that was expected to be located
* at the specified index of the given parent token's children array
* @param childId ID of the child token that was expected to be located at the specified index of the given parent
* token's children array
* @param isPending A boolean value signifying whether the child token was transferred from the pending child tokens
* array (`true`) or from the active child tokens array (`false`)
*/
function _afterTransferChild(
uint256 tokenId,
uint256 childIndex,
address childAddress,
uint256 childId,
bool isPending
) internal virtual {}
/**
* @notice Hook that is called before a pending child tokens array of a given token is cleared.
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param tokenId ID of the token that will reject all of the pending child tokens
*/
function _beforeRejectAllChildren(uint256 tokenId) internal virtual {}
/**
* @notice Hook that is called after a pending child tokens array of a given token is cleared.
* @dev To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
* @param tokenId ID of the token that has rejected all of the pending child tokens
*/
function _afterRejectAllChildren(uint256 tokenId) internal virtual {}
// HELPERS
/**
* @notice Used to remove a specified child token form an array using its index within said array.
* @dev The caller must ensure that the length of the array is valid compared to the index passed.
* @dev The Child struct consists of the following values:
* [
* tokenId,
* contractAddress
* ]
* @param array An array od Child struct containing info about the child tokens in a given child tokens array
* @param index An index of the child token to remove in the accompanying array
*/
function _removeChildByIndex(Child[] storage array, uint256 index) private {
array[index] = array[array.length - 1];
array.pop();
}
}