From 3dfc0a44f8ca97dec5a734ff9bd73449ef87f7b4 Mon Sep 17 00:00:00 2001 From: Hadrien Croubois Date: Mon, 14 Feb 2022 16:55:43 +0100 Subject: [PATCH] ERC1155 after token transfer hook (#3166) * add Hooks _afterTokenTransfer * avoid duplicate call to _asSingleton * add changelog entry * update changelog link to PR * Update CHANGELOG.md Co-authored-by: Francisco Giordano Co-authored-by: CryptoV8 <91189073+CryptoV8@users.noreply.github.com> Co-authored-by: Francisco Giordano --- CHANGELOG.md | 1 + contracts/token/ERC1155/ERC1155.sol | 53 +++++++++++++++++++++++++++-- 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/CHANGELOG.md b/CHANGELOG.md index 92aec8621..24620ae80 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -4,6 +4,7 @@ * `AccessControl`: add a virtual `_checkRole(bytes32)` function that can be overriden to alter the `onlyRole` modifier behavior. ([#3137](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3137)) * `EnumerableMap`: add new `AddressToUintMap` map type. ([#3150](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3150)) + * `ERC1155`: Add a `_afterTokenTransfer` hook for improved extensibility. ([#3166](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/3166)) ## 4.5.0 (2022-02-09) diff --git a/contracts/token/ERC1155/ERC1155.sol b/contracts/token/ERC1155/ERC1155.sol index ffdd8cd78..bc3de9ce1 100644 --- a/contracts/token/ERC1155/ERC1155.sol +++ b/contracts/token/ERC1155/ERC1155.sol @@ -167,8 +167,10 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { require(to != address(0), "ERC1155: transfer to the zero address"); address operator = _msgSender(); + uint256[] memory ids = _asSingletonArray(id); + uint256[] memory amounts = _asSingletonArray(amount); - _beforeTokenTransfer(operator, from, to, _asSingletonArray(id), _asSingletonArray(amount), data); + _beforeTokenTransfer(operator, from, to, ids, amounts, data); uint256 fromBalance = _balances[id][from]; require(fromBalance >= amount, "ERC1155: insufficient balance for transfer"); @@ -180,6 +182,8 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { emit TransferSingle(operator, from, to, id, amount); _doSafeTransferAcceptanceCheck(operator, from, to, id, amount, data); + + _afterTokenTransfer(operator, from, to, ids, amounts, data); } /** @@ -221,6 +225,8 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { emit TransferBatch(operator, from, to, ids, amounts); _doSafeBatchTransferAcceptanceCheck(operator, from, to, ids, amounts, data); + + _afterTokenTransfer(operator, from, to, ids, amounts, data); } /** @@ -266,13 +272,17 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { require(to != address(0), "ERC1155: mint to the zero address"); address operator = _msgSender(); + uint256[] memory ids = _asSingletonArray(id); + uint256[] memory amounts = _asSingletonArray(amount); - _beforeTokenTransfer(operator, address(0), to, _asSingletonArray(id), _asSingletonArray(amount), data); + _beforeTokenTransfer(operator, address(0), to, ids, amounts, data); _balances[id][to] += amount; emit TransferSingle(operator, address(0), to, id, amount); _doSafeTransferAcceptanceCheck(operator, address(0), to, id, amount, data); + + _afterTokenTransfer(operator, address(0), to, ids, amounts, data); } /** @@ -304,6 +314,8 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { emit TransferBatch(operator, address(0), to, ids, amounts); _doSafeBatchTransferAcceptanceCheck(operator, address(0), to, ids, amounts, data); + + _afterTokenTransfer(operator, address(0), to, ids, amounts, data); } /** @@ -322,8 +334,10 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { require(from != address(0), "ERC1155: burn from the zero address"); address operator = _msgSender(); + uint256[] memory ids = _asSingletonArray(id); + uint256[] memory amounts = _asSingletonArray(amount); - _beforeTokenTransfer(operator, from, address(0), _asSingletonArray(id), _asSingletonArray(amount), ""); + _beforeTokenTransfer(operator, from, address(0), ids, amounts, ""); uint256 fromBalance = _balances[id][from]; require(fromBalance >= amount, "ERC1155: burn amount exceeds balance"); @@ -332,6 +346,8 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { } emit TransferSingle(operator, from, address(0), id, amount); + + _afterTokenTransfer(operator, from, address(0), ids, amounts, ""); } /** @@ -365,6 +381,8 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { } emit TransferBatch(operator, from, address(0), ids, amounts); + + _afterTokenTransfer(operator, from, address(0), ids, amounts, ""); } /** @@ -411,6 +429,35 @@ contract ERC1155 is Context, ERC165, IERC1155, IERC1155MetadataURI { bytes memory data ) internal virtual {} + /** + * @dev Hook that is called after any token transfer. This includes minting + * and burning, as well as batched variants. + * + * The same hook is called on both single and batched variants. For single + * transfers, the length of the `id` and `amount` arrays will be 1. + * + * Calling conditions (for each `id` and `amount` pair): + * + * - When `from` and `to` are both non-zero, `amount` of ``from``'s tokens + * of token type `id` will be transferred to `to`. + * - When `from` is zero, `amount` tokens of token type `id` will be minted + * for `to`. + * - when `to` is zero, `amount` of ``from``'s tokens of token type `id` + * will be burned. + * - `from` and `to` are never both zero. + * - `ids` and `amounts` have the same, non-zero length. + * + * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks]. + */ + function _afterTokenTransfer( + address operator, + address from, + address to, + uint256[] memory ids, + uint256[] memory amounts, + bytes memory data + ) internal virtual {} + function _doSafeTransferAcceptanceCheck( address operator, address from,