TypeError: Derived contract must override function "supportsInterface". Two or more base classes define function with same name and parameter types.
--> royalty.sol:9:1: | 9 | contract NftMarketplace is ERC721URIStorage,ERC2981 { | ^ (Relevant source part starts here and spans across multiple lines). Note: Definition in "ERC721": --> @openzeppelin/contracts/token/ERC721/ERC721.sol:52:5: | 52 | function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) { | ^ (Relevant source part starts here and spans across multiple lines). Note: Definition in "ERC2981": --> @openzeppelin/contracts/token/common/ERC2981.sol:36:5: | 36 | function supportsInterface(bytes4 interfaceId) public view virtual override(IERC165, ERC165) returns (bool) { | ^ (Relevant source part starts here and spans across multiple lines). ---------------code------------------------------------------------- // SPDX-License-Identifier: UNLICENSED pragma solidity ^0.8.0; import "@openzeppelin/contracts/utils/Counters.sol"; import "@openzeppelin/contracts/token/ERC721/ERC721.sol"; import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol"; import "@openzeppelin/contracts/token/common/ERC2981.sol"; import "hardhat/console.sol";
contract NftMarketplace is ERC721URIStorage,ERC2981 { using Counters for Counters.Counter; //_tokenIds variable has the most recent minted tokenId Counters.Counter private _tokenIds; //Keeps track of the number of items sold on the marketplace Counters.Counter private _itemsSold; //owner is the contract address that created the smart contract address payable owner; //The fee charged by the marketplace to be allowed to list an NFT uint256 listPrice = 0.01 ether;
//The structure to store info about a listed token
struct ListedToken {
uint256 tokenId;
address payable owner;
address payable seller;
uint256 price;
bool currentlyListed;
}
//the event emitted when a token is successfully listed
event TokenListedSuccess(
uint256 indexed tokenId,
address owner,
address seller,
uint256 price,
bool currentlyListed
);
//This mapping maps tokenId to token info and is helpful when retrieving details about a tokenId
mapping(uint256 => ListedToken) private idToListedToken;
constructor() ERC721("NFTMarketplace", "NFTM") {
owner = payable(msg.sender);
}
function updateListPrice(uint256 _listPrice) public payable {
require(owner == msg.sender, "Only owner can update listing price");
listPrice = _listPrice;
}
function getListPrice() public view returns (uint256) {
return listPrice;
}
function getLatestIdToListedToken()
public
view
returns (ListedToken memory)
{
uint256 currentTokenId = _tokenIds.current();
return idToListedToken[currentTokenId];
}
function getListedTokenForId(
uint256 tokenId
) public view returns (ListedToken memory) {
return idToListedToken[tokenId];
}
function getCurrentToken() public view returns (uint256) {
return _tokenIds.current();
}
//The first time a token is created, it is listed here
function createToken(
string memory tokenURI,
uint256 price,
uint96 feeNumerator
) public payable returns (uint) {
//Increment the tokenId counter, which is keeping track of the number of minted NFTs
_tokenIds.increment();
uint256 newTokenId = _tokenIds.current();
//Mint the NFT with tokenId newTokenId to the address who called createToken
_safeMint(msg.sender, newTokenId);
//Map the tokenId to the tokenURI (which is an IPFS URL with the NFT metadata)
_setTokenURI(newTokenId, tokenURI);
//Helper function to update Global variables and emit an event
createListedToken(newTokenId, price,feeNumerator);
return newTokenId;
}
function createListedToken(uint256 tokenId, uint256 price,uint96 feeNumerator) private {
//Make sure the sender sent enough ETH to pay for listing
require(msg.value == listPrice, "Have to send ether equal to the listing price");
//Just sanity check
require(price > 0, "Make sure the price isn't negative");
//Update the mapping of tokenId's to Token details, useful for retrieval functions
idToListedToken[tokenId] = ListedToken(
tokenId,
payable(address(this)),
payable(msg.sender),
price,
true
);
_setTokenRoyalty(tokenId,msg.sender,feeNumerator);
_transfer(msg.sender, address(this), tokenId);
//Emit the event for successful transfer. The frontend parses this message and updates the end user
emit TokenListedSuccess(
tokenId,
address(this),
msg.sender,
price,
true
);
}
//This will return all the NFTs currently listed to be sold on the marketplace
function getAllNFTs() public view returns (ListedToken[] memory) {
uint nftCount = _tokenIds.current();
ListedToken[] memory tokens = new ListedToken[](nftCount);
uint currentIndex = 0;
uint currentId;
//at the moment currentlyListed is true for all, if it becomes false in the future we will
//filter out currentlyListed == false over here
for (uint i = 0; i < nftCount; i++) {
currentId = i + 1;
ListedToken storage currentItem = idToListedToken[currentId];
tokens[currentIndex] = currentItem;
currentIndex += 1;
}
//the array 'tokens' has the list of all NFTs in the marketplace
return tokens;
}
//Returns all the NFTs that the current user is owner or seller in
function getMyNFTs() public view returns (ListedToken[] memory) {
uint totalItemCount = _tokenIds.current();
uint itemCount = 0;
uint currentIndex = 0;
uint currentId;
//Important to get a count of all the NFTs that belong to the user before we can make an array for them
for (uint i = 0; i < totalItemCount; i++) {
if (
idToListedToken[i + 1].owner == msg.sender ||
idToListedToken[i + 1].seller == msg.sender
) {
itemCount += 1;
}
}
//Once you have the count of relevant NFTs, create an array then store all the NFTs in it
ListedToken[] memory items = new ListedToken[](itemCount);
for (uint i = 0; i < totalItemCount; i++) {
if (
idToListedToken[i + 1].owner == msg.sender ||
idToListedToken[i + 1].seller == msg.sender
) {
currentId = i + 1;
ListedToken storage currentItem = idToListedToken[currentId];
items[currentIndex] = currentItem;
currentIndex += 1;
}
}
return items;
}
function executeSale(uint256 tokenId) public payable {
uint price = idToListedToken[tokenId].price;
address seller = idToListedToken[tokenId].seller;
require(
msg.value == price,
"Please submit the asking price in order to complete the purchase"
);
//update the details of the token
idToListedToken[tokenId].currentlyListed = true;
idToListedToken[tokenId].seller = payable(msg.sender);
_itemsSold.increment();
//Actually transfer the token to the new owner
_transfer(address(this), msg.sender, tokenId);
//approve the marketplace to sell NFTs on your behalf
approve(address(this), tokenId);
//fetching royalty info
(address recipient, uint256 amount) = royaltyInfo(tokenId, price);
//transfer royalty amount to the artist
payable(recipient).transfer(amount);
//Transfer the listing fee to the marketplace creator
payable(owner).transfer(listPrice);
//Transfer the proceeds from the sale to the seller of the NFT
payable(seller).transfer(msg.value);
}
//We might add a resell token function in the future
//In that case, tokens won't be listed by default but users can send a request to actually list a token
//Currently NFTs are listed by default
}
