forked from DecentralizedClimateFoundation/DCIPs
60 lines
2.2 KiB
Solidity
60 lines
2.2 KiB
Solidity
// SPDX-License-Identifier: CC0-1.0
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pragma solidity 0.8.11;
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import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
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import "./IERC721Consumable.sol";
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contract ERC721Consumable is IERC721Consumable, ERC721 {
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// Mapping from token ID to consumer address
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mapping(uint256 => address) _tokenConsumers;
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constructor (string memory name_, string memory symbol_) ERC721(name_, symbol_) {}
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/**
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* @dev Returns true if the `msg.sender` is approved, owner or consumer of the `tokenId`
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*/
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function _isApprovedOwnerOrConsumer(uint256 tokenId) internal view returns (bool) {
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return _isApprovedOrOwner(msg.sender, tokenId) || _tokenConsumers[tokenId] == msg.sender;
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}
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/**
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* @dev See {IERC721Consumable-consumerOf}
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*/
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function consumerOf(uint256 _tokenId) view external returns (address) {
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require(_exists(_tokenId), "ERC721Consumable: consumer query for nonexistent token");
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return _tokenConsumers[_tokenId];
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}
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/**
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* @dev See {IERC721Consumable-changeConsumer}
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*/
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function changeConsumer(address _consumer, uint256 _tokenId) external {
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address owner = this.ownerOf(_tokenId);
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require(msg.sender == owner || msg.sender == getApproved(_tokenId) || isApprovedForAll(owner, msg.sender),
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"ERC721Consumable: changeConsumer caller is not owner nor approved");
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_changeConsumer(owner, _consumer, _tokenId);
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}
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/**
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* @dev See {IERC165-supportsInterface}.
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*/
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function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC721) returns (bool) {
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return interfaceId == type(IERC721Consumable).interfaceId || super.supportsInterface(interfaceId);
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}
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function _beforeTokenTransfer(address _from, address _to, uint256 _tokenId) internal virtual override (ERC721) {
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super._beforeTokenTransfer(_from, _to, _tokenId);
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_changeConsumer(_from, address(0), _tokenId);
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}
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/**
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* @dev Changes the consumer
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* Requirement: `tokenId` must exist
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*/
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function _changeConsumer(address _owner, address _consumer, uint256 _tokenId) internal {
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_tokenConsumers[_tokenId] = _consumer;
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emit ConsumerChanged(_owner, _consumer, _tokenId);
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}
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}
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