Discussion on: How to Build a Full Stack NFT Marketplace - V2 (2022)

[Mateus Ferreira]

Solved my issue yesterday by writing a custom function to tranfer tokens on my NFT contract. Like this:

contract NFT is ERC721URIStorage {
    (...)
    function transferToken(address from, address to, uint256 tokenId) external {
        require(ownerOf(tokenId) == from, "From address must be token owner");
        _transfer(from, to, tokenId);
    }
}

And in my Market Contract:

import "./NFT.sol";

contract NFTMarket is ReentrancyGuard {
    (...)
    function putItemToResell(address nftContract, uint256 itemId, uint256 newPrice)
        public
        payable
        nonReentrant
        onlyItemOwner(itemId)
    {
        (...)
        uint256 tokenId = idToMarketItem[itemId].tokenId;

        NFT tokenContract = NFT(nftContract);

        tokenContract.transferToken(msg.sender, address(this), tokenId);        
    }

}

Don't know all the implications of this solutions and if it may fail or cause security issues somehow but it solved my problem for know.

[Sione]

Thanks that solution works but I agree with the implications it may bring if any. Thank you though! Ill update you if I find another stable solution.

[Mateus Ferreira]

my pleasure! Keep me posted about the solutions you may find.

[Javilonte]

Hi, thank you for posting this, i would like to use your function on my code but it says "onlyItemOwner(itemId)" never used, am i missing something? thanks again!

[Mateus Ferreira]

Hey there! its a modifier that you're missing. I added this to my contract so I can use it in functions to ensure only the item's owner can execute it:

    modifier onlyItemOwner(uint256 id) {
        require(
            idToMarketItem[id].owner == msg.sender,
            "Only product owner can do this operation"
        );
        _;
    }

[Javilonte]

thanksss