So I have this error that says (TypeError: Contract "ERC721Enumerable" should be marked as abstract.) and I am unaware on how should I mark the smart contract as abstract. I'm still an absolute beginner so I have no clue how to do certain things yet.
I think I've had this problem before though I have forgotten how I solved it since that was a long time ago and is out of the range of what I can remember.
also here is the program:
pragma solidity ^0.8.0;
import './ERC721.sol';
contract ERC721Enumerable is ERC721 {
uint256[] private _allTokens;
// CHALLENGE! Write out mapping yourself!!
// mapping from tokenId to position in _allTokens array
mapping(uint256 => uint256) private _allTokensIndex;
// mapping of owner to list of all owner token ids
mapping(address => uint256[]) private _ownedTokens;
// mapping from token ID index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
// #notice count NFTs tracked by this contract
// #return A count of valid NFTs tracked by this contract, where each on of
// them has an assigned and queryable ower not equal to the zero address
// #notice Enumerate valid NFT's
// #dev Throws if '_index" >= 'totalSupply()'.
// #param _index A couter less than 'totalSupply()'
// #return The token identifier for the '_index'th NFt,
// (sort order not specified)
//function tokenByIndex(uint256 _index) external view returns (uint256);
// #notice Enumerate NFTs assigned to an owner
// #dev Throws if '_index' >= 'balanceOf(_owner)' or if
// '_owner' is the zero address, representing invalid NFTs.
// #param _owner An address where we are interested in NFTs owned by them
// #param _index A counter less than 'balanceOf(_owner)'
// #return The token identifier for the '_index'th NFT assigned to '_owner',
// (sort order not specfied)
//function tokenOfOwnerByIndex(address _owner, uint256 _index) external view returns (uint256);
function _mint(address to, uint256 tokenId) internal override(ERC721) {
super._mint(to, tokenId);
// 2 things!
// a. add tokens too the owner
// b. all tokens to out totalSupply - allToken
_addTokensToAllTokenEnumeration(tokenId);
_addTokensToOwnerEnumeration(to, tokenId);
}
// add tokens to the _allTokens array and set the position of the tokens indexes
function _addTokensToAllTokenEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
// two function - one that returns token by the index
// another one thata retruns tokenByOwnerIndex
function tokenByIndex(uint256 index) public view returns(uint256) {
// make sure that the undex is not our of bounds of the
// total supply
require(index < totalSupply(), 'global index is out of bounds!');
return _allTokens[index];
}
function tokenOfOwnerByIndex(address owner, uint256 index) external view returns (uint256){
require(index < balanceOf(owner), 'owner is out of bounds!');
return _allTokens[index];
}
// return the total supply of the _allTokens array
function totalSupply() public view returns(uint256) {
return _allTokens.length;
}
function _addTokensToOwnerEnumeration(address to, uint256 tokenId) public {
_ownedTokensIndex[tokenId] = _ownedTokens[to].length;
_ownedTokens[to].push(tokenId);
}
// #notice Transfer owner ship of an NFT -- THE REAL CALLER IS RESPOSIBLE
// TO CONFIRM THAT '_to' IS CAPABLE OF RECEIVING NFTS OR ELSE
// THEY MAY BE PERMANENTLY LOST
// #dev Throws untess 'msg.sender' is the current owner, an authorized
// operator, or the approved address for this NFT. Throws if '_from' is
// not current owner, Throws if '_to' is the zero address. Throws if
// '_tokenId' is not a valid NFT.
// #param _from The current owner of the NFT
// #param _to the new owner
// #param _tokenId The NFT to transfer
function transferFrom(address _from, address _to, uint256 _tokenId) external payable;
} ```
Your contract not fully implement all the functions of the ERC721 contract..
Refer
https://ethereum.stackexchange.com/questions/112724/error-contract-should-be-marked-as-abstract
https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/ERC721.sol
Related
I am working on an NFT Marketplace creation task with Truffle. For that, I am using an ERC4907 smart contract and trying to compile it. Following is my ERC4907 code.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "#openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "./IERC4907.sol";
contract ERC4907 is ERC721URIStorage, IERC4907 {
struct UserInfo {
address user; // address of user role
uint64 expires; // unix timestamp, user expires
}
mapping(uint256 => UserInfo) internal _users;
constructor(string memory name_, string memory symbol_) ERC721(name_, symbol_) {}
/// #notice set the user and expires of a NFT
/// #dev The zero address indicates there is no user
/// Throws if `tokenId` is not valid NFT
/// #param user The new user of the NFT
/// #param expires UNIX timestamp, The new user could use the NFT before expires
function setUser(
uint256 tokenId,
address user,
uint64 expires
) public virtual override {
require(
_isApprovedOrOwner(msg.sender, tokenId),
"ERC721: transfer caller is not owner nor approved"
);
UserInfo storage info = _users[tokenId];
info.user = user;
info.expires = expires;
emit UpdateUser(tokenId, user, expires);
}
/// #notice Get the user address of an NFT
/// #dev The zero address indicates that there is no user or the user is expired
/// #param tokenId The NFT to get the user address for
/// #return The user address for this NFT
function userOf(uint256 tokenId)
public
view
virtual
override
returns (address)
{
if (uint256(_users[tokenId].expires) >= block.timestamp) {
return _users[tokenId].user;
} else {
return address(0);
}
}
/// #notice Get the user expires of an NFT
/// #dev The zero value indicates that there is no user
/// #param tokenId The NFT to get the user expires for
/// #return The user expires for this NFT
function userExpires(uint256 tokenId)
public
view
virtual
override
returns (uint256)
{
return _users[tokenId].expires;
}
/// #dev See {IERC165-supportsInterface}.
function supportsInterface(bytes4 interfaceId)
public
view
virtual
override
returns (bool)
{
return
interfaceId == type(IERC4907).interfaceId ||
super.supportsInterface(interfaceId);
}
function _beforeTokenTransfer(
address from,
address to,
uint256 tokenId
) internal virtual override {
super._beforeTokenTransfer(from, to, tokenId);
if (from != to && _users[tokenId].user != address(0)) {
delete _users[tokenId];
emit UpdateUser(tokenId, address(0), 0);
}
}
}
I am getting the following error when trying to compile it. Error is on the "_beforeTokenTransfer" function.
CompileError: TypeError: Wrong argument count for function call: 3 arguments given but expected 4.
--> project:/contracts/ERC4907.sol:87:5:
|
87 | super._beforeTokenTransfer(from, to, tokenId);
|
I am using following versions
Truffle v5.6.8 (core: 5.6.8)
Ganache v7.5.0
Solidity v0.5.16 (solc-js)
Node v16.17.1
Web3.js v1.7.4
I have checked with the reference implementation on https://eips.ethereum.org/EIPS/eip-4907 . But it is still the same code.
Can someone please show me what I have mistaken here? Thank You
EDIT
As answered by #Muhammad Hassan, it was identified that there was a breaking change in the _beforeTokenTransfer function on ERC721 very recently(2022-11-08). Please refer the changelog via the following link.
https://github.com/OpenZeppelin/openzeppelin-contracts/blob/7c5f6bc2c8743d83443fa46395d75f2f3f99054a/CHANGELOG.md#breaking-changes
Adding the additional argument "uint256 batchSize" resolved the compilation issue. Thank you.
Erc4907 is an extention of Erc721 which you may already know. so when calling super._beforeTokenTransfer() you are actually tapping ERC721's function.
If you go to ERC721 you can see that indeed it takes 4 arguments for
function _beforeTokenTransfer(
address from,
address to,
uint256, /* firstTokenId */
uint256 batchSize
) internal virtual {}
You can visit the oz erc721 github page for more.
The argument you are missing is uint256 batchSize.
help, I'm getting errors on my code saying: TypeError: Type address is not implicitly convertible to expected type uint256. And I am in desperate need of help. I don't know what to do and if you need the full code pls say so
I think it has something to do with the address though I am not quite sure since I am still a beginner, so I am absolutely clueless so far. If you do know how to help me solve please say so.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import './ERC721.sol';
contract ERC721Enumerable is ERC721 {
uint256[] private _allTokens;
// CHALLENGE! Write out mapping yourself!!
// mapping from tokenId to position in _allTokens array
mapping(uint256 => uint256) private _allTokensIndex;
// mapping of owner to list of all owner token ids
mapping(uint256 => uint256[]) private _ownedTokens;
// mapping from token ID index of the owner tokens list
mapping(uint256 => uint256) private _ownedTokensIndex;
// #notice count NFTs tracked by this contract
// #return A count of valid NFTs tracked by this contract, where each on of
// them has an assigned and queryable ower not equal to the zero address
// #notice Enumerate valid NFT's
// #dev Throws if '_index" >= 'totalSupply()'.
// #param _index A couter less than 'totalSupply()'
// #return The token identifier for the '_index'th NFt,
// (sort order not specified)
//function tokenByIndex(uint256 _index) external view returns (uint256);
// #notice Enumerate NFTs assigned to an owner
// #dev Throws if '_index' >= 'balanceOf(_owner)' or if
// '_owner' is the zero address, representing invalid NFTs.
// #param _owner An address where we are interested in NFTs owned by them
// #param _index A counter less than 'balanceOf(_owner)'
// #return The token identifier for the '_index'th NFT assigned to '_owner',
// (sort order not specfied)
//function tokenOfOwnerByIndex(address _owner, uint256 _index) external view returns (uint256);
function _mint(address to, uint256 tokenId) internal override(ERC721) {
super._mint(to, tokenId);
// 2 things!
// a. add tokens too the owner
// b. all tokens to out totalSupply - allToken
_addTokensToAllTokenEnumeration(tokenId);
_addTokensToOwnerEnumeration(to, tokenId);
}
// add tokens to the _allTokens array and set the position of the tokens indexes
function _addTokensToAllTokenEnumeration(uint256 tokenId) private {
_allTokensIndex[tokenId] = _allTokens.length;
_allTokens.push(tokenId);
}
// two function - one that returns token by the index
// another one thata retruns tokenByOwnerIndex
function tokenByIndex(uint256 index) public view returns(uint256) {
// make sure that the undex is not our of bounds of the
// total supply
require(index < totalSupply(), 'global index is out of bounds');
return _allTokens[index];
}
// return the total supply of the _allTokens array
function totalSupply() public view returns(uint256) {
return _allTokens.length;
}
function _addTokensToOwnerEnumeration(address to, uint256 tokenId) public {
_ownedTokensIndex[tokenId] = _ownedTokens[to].length;
_ownedTokens[to].push(tokenId);
}
}
In your code, your mapping is wrong. In your function _addTokensToOwnerEnumeration() you have taken address as mapping key. but in your declaration you have taken
//this is wrong as per you have used in your function
mapping(uint256=> uint256[]) private _ownedTokens;
// You have to declare like this.
mapping(address=>uint256[]) private _ownedTokens;
_ownedTokens have uint256 as key type it should be address type:
// mapping of owner to list of all owner token ids
mapping(address => uint256[]) private _ownedTokens;
For example I don't want to store ETH on Smart Contract but to the contract owner. Then how to implement withdrawal from the contract owner?
pragma solidity ^0.8.7;
contract WDfromContractOwner {
address public owner;
constructor() {
owner=msg.sender;
}
function deposit() external payable returns (bool) {
payable(owner).transfer(msg.value);
return true;
}
function withdrawal() external returns (bool) {
// Witdrawal from owner address....???
return true;
}
}
A smart contract is not able to pull ETH from an address (other than the address sending the ETH to the contract). The transfer needs to always be originated from and signed by the sender (in your case the owner).
However, it can pull tokens owned by an address. The sender (owner) needs to approve() the amount at first, interacting with the token contract from their address. Then your contract can invoke the token's transferFrom() function.
pragma solidity ^0.8;
interface IERC20 {
function transferFrom(address, address, uint256) external returns (bool);
}
contract WDfromContractOwner {
address public owner;
function withdrawToken() external {
// Only reachable from the mainnet.
// Transfers from other networks (such as Remix VM) will fail.
address mainnetUSDT = 0xdAC17F958D2ee523a2206206994597C13D831ec7;
address receiver = msg.sender; // address of the user executing the `withdrawToken()`
uint256 amount = 5 * 1e6; // 5 USDT, 6 decimals
require(
// the `owner` needs to execute `approve()` on the token contract directly from the `owner` address
// so that the `WDfromContractOwner` contract can spend their tokens
IERC20(mainnetUSDT).transferFrom(owner, receiver, amount)
);
}
}
You can get the approved amount using web3.js:
const USDTAddress = "0xdAC17F958D2ee523a2206206994597C13D831ec7";
const ownerAddress = "0xFFfFfFffFFfffFFfFFfFFFFFffFFFffffFfFFFfF";
// just the `balanceOf()` is sufficient in this case
const ABI = [
{"constant":true,"inputs":[{"name":"who","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"}
];
const USDTContract = new web3.eth.Contract(ABI, USDTAddress);
const approved = await USDTContract.methods.balanceOf(ownerAddress).call();
console.log(approved);
If you are already are transferring the funds to the owner each time an user deposit it should not be necessary, but if you want you could do it anyway, you have different options like passing the amount as a parameter, have a default or a minimum amount, etc, but for simplicity to withdraw all the funds just add this two lines in the function
(bool result,)= payable(owner).call{value: address(this).balance }("");
return result
pragma solidity ^0.4.21;
contract Lottery {
address public manager;
address[] public players;
constructor() public {
manager = msg.sender;
}
function enter() public payable {
require(msg.value > .01 ether);
players.push(msg.sender);
}
function random() private view returns (uint) {
return uint(keccak256(abi.encodePacked(block.difficulty, now, players)));
}
function pickWinner() public restricted {
uint index = random() % players.length;
players[index].transfer(address(this).balance);
players = new address[](0);
}
function getPlayers() public view returns (address[]) {
return players;
}
modifier restricted() {
require(msg.sender == manager);
_;
}
}
I want o change the function
function enter() public payable {
require(msg.value > .01 ether);
players.push(msg.sender);
}
Instead of ether, user use our token/erc20 to enter the lottery
You can define an interface (in your contract) of the token contract. Since you're only going to be using the transferFrom() function, this is the only function that you need to define in the interface (no matter that the token contract contains other functions as well).
interface IERC20 {
function transferFrom(address _from, address _to, uint256 _amount) external returns (bool);
}
The you can execute the transferFrom() function of the token, passing it arguments:
from: the user executing your enter() function
to: your contract
amount: Assuming the token has 18 decimals (most tokens do), you can use the ether helper unit, because it effectively calculates "0.01 * 10^18 (or 10^16, or 10000000000000000) of the token smallest units", which is 0.01 of the token. Otherwise, you'll need to recalculate this number based on the token decimals.
function enter() public payable {
IERC20 token = IERC20(address(0x123)); // Insert the token contract address instead of `0x123`
require(token.transferFrom(msg.sender, address(this), .01 ether));
players.push(msg.sender);
}
Important: Mind that the user needs to approve() your contract to spend their tokens beforehand (from their address), otherwise the token transfer would fail. There's a security reason for that, read more about it in the bottom part of this answer.
I have deployed smart contract using remix IDE, launched with Injected Web3 on Ropsten test network. I could call BuyTokens function within solidity IDE successfully, but when tried to buy tokens with metamask from other address transaction get reverted. I can see the difference between those operations on ropsten.etherscan explorer - the difference is in Input Data field.
Metamask transaction has value 0x and transaction via remix is:
Function: buyTokens() ***
MethodID: 0xd0febe4c
Code:
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.0;
contract Token {
// Track how many tokens are owned by each address.
mapping (address => uint256) public balanceOf;
// Modify this section
string public name = "DemoCoin";
string public symbol = "DC";
uint8 public decimals = 8;
uint256 public totalSupply = 1000000000 * (uint256(10) ** decimals);
address public owner;
//uint scaler = 10e18; // == 1 ETH in wei
//uint public coinPrice = 20; //initial price => 20 cents
event Transfer(address indexed from, address indexed to, uint256 value);
constructor() {
// Initially assign all tokens to the contract's creator.
owner = msg.sender;
balanceOf[msg.sender] = totalSupply;
emit Transfer(address(0), msg.sender, totalSupply);
}
// Might be executed automaticlly
// https://blog.chronologic.network/schedule-your-transaction-now-using-mycrypto-and-myetherwallet-17b48166b412
// function changeCoinPrice() public {
// uint newCoinPrice;
// require(msg.sender == address(0));
// coinPrice = newCoinPrice;
// }
function buyTokens() public payable {
// msg.value in wei so 1ETH = 10e18
// lets set 0.20 cents for 1 token
uint paidAmount;
require(balanceOf[msg.sender] >= paidAmount);
require(balanceOf[owner] >= value);
uint tokens;
tokens = value/10e14;
balanceOf[owner] -= tokens;
balanceOf[msg.sender] += tokens;
emit Transfer(owner, msg.sender, tokens);
}
function msgSenderBalancce() public view returns (uint) {
return balanceOf[msg.sender];
}
function withDrawEth() public view {
require(msg.sender == owner);
}
}
Why these methods are called diffrently? And how to add method id in metamask? Or am I missing something and this should be handled in other way?
MetaMask has a very basic UI. It only allows transfers of ETH and standardized tokens, but it doesn't show any buttons to call other contract functions. It also doesn't allow creating any custom buttons in their UI.
You'll need to set the data field of the transaction to 0xd0febe4c (which effectively executes the buyTokens() function).
But - they also don't allow specifying the data field value manually in the UI, so you'll need to preset it using the Ethereum provider API.
Your web app connects to the user's MetaMask acccount. It opens a MetaMask window and the user needs to manually confirm the connect.
The web app sends a request to MetaMask specifying the transaction with data field value.
The user confirms the transaction (which now includes the data field value 0xd0febe4c) in their MetaMask UI.