5dfe7215a9
* Initial migration to Solidity 0.6.x - v3.0 first steps (#2063) * Initial migration, missing GSN, 721, 777 and Crowdsales. * Add _beforeTokenOperation and _afterTokenOperation. * Add documentation for hooks. * Add hooks doc * Add missing drafts * Add back ERC721 with hooks * Bring back ERC777 * Notes on hooks * Bring back GSN * Make functions virtual * Make GSN overrides explicit * Fix ERC20Pausable tests * Remove virtual from some view functions * Update linter * Delete examples * Remove unnecessary virtual * Remove roles from Pausable * Remove roles * Remove users of roles * Adapt ERC20 tests * Fix ERC721 tests * Add all ERC721 hooks * Add ERC777 hooks * Fix remaining tests * Bump compiler version * Move 721BurnableMock into mocks directory * Remove _before hooks * Fix tests * Upgrade linter * Put modifiers last * Remove _beforeTokenApproval and _beforeOperatorApproval hooks
26 lines
1.2 KiB
Solidity
26 lines
1.2 KiB
Solidity
pragma solidity ^0.6.0;
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/**
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* @title ERC721 token receiver interface
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* @dev Interface for any contract that wants to support safeTransfers
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* from ERC721 asset contracts.
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*/
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abstract contract IERC721Receiver {
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/**
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* @notice Handle the receipt of an NFT
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* @dev The ERC721 smart contract calls this function on the recipient
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* after a {IERC721-safeTransferFrom}. This function MUST return the function selector,
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* otherwise the caller will revert the transaction. The selector to be
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* returned can be obtained as `this.onERC721Received.selector`. This
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* function MAY throw to revert and reject the transfer.
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* Note: the ERC721 contract address is always the message sender.
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* @param operator The address which called `safeTransferFrom` function
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* @param from The address which previously owned the token
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* @param tokenId The NFT identifier which is being transferred
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* @param data Additional data with no specified format
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* @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
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*/
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function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
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public virtual returns (bytes4);
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}
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