안녕하세요.
ide.klaytn.com 에서 BaoBab 에서 KIP7 규격의 토큰을 생성후 trasfer 하는데 아래와 같은 오류가 발생합니다.
정상적으로 deploy 는 되어서 contract address 가 생성되었으며 해당 토큰을 transfer 하는데 오류가 발생하는 상황입니다.
해당 컨트렉트 주소로 caver-java 에서 transfer 했을 때도 동일한 증상입니다. 뭐가 잘못 되었을까요?
이때의 Run 탭의 상단 패널도 스샷으로 보내드립니다. 잔고는 충분한 상황입니다.
감사합니다.
안녕하세요,
클레이튼 포럼에 질문을 올려주셔서 감사드립니다.
위 에러는 gas limit을 estimation하는 과정에서 발생한 에러로 보입니다. 실제 함수 구현을 보면 도움이 될 것 같은데요, 어떤 함수를 호출하셨고, 그 함수의 구현을 알려주실 수 있나요?
코드를 붙입니다.
배포후에 transfer(address to, uint256 value) 를 호출했습니다.
pragma solidity ^0.5.0;
library SafeMath {
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a, "SafeMath: addition overflow");
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a, "SafeMath: subtraction overflow");
uint256 c = a - b;
return c;
}
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b, "SafeMath: multiplication overflow");
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
// Solidity only automatically asserts when dividing by 0
require(b > 0, "SafeMath: division by zero");
uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return c;
}
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b != 0, "SafeMath: modulo by zero");
return a % b;
}
}
library Address {
function isContract(address account) internal view returns (bool) {
// This method relies in extcodesize, which returns 0 for contracts in
// construction, since the code is only stored at the end of the
// constructor execution.
uint256 size;
// solhint-disable-next-line no-inline-assembly
assembly { size := extcodesize(account) }
return size > 0;
}
}
library Roles {
struct Role {
mapping (address => bool) bearer;
}
/**
* @dev Give an account access to this role.
*/
function add(Role storage role, address account) internal {
require(!has(role, account), "Roles: account already has role");
role.bearer[account] = true;
}
/**
* @dev Remove an account's access to this role.
*/
function remove(Role storage role, address account) internal {
require(has(role, account), "Roles: account does not have role");
role.bearer[account] = false;
}
/**
* @dev Check if an account has this role.
* @return bool
*/
function has(Role storage role, address account) internal view returns (bool) {
require(account != address(0), "Roles: account is the zero address");
return role.bearer[account];
}
}
/**
* @dev Interface of the KIP-13 standard, as defined in the
* [KIP-13](http://kips.klaytn.com/KIPs/kip-13-interface_query_standard).
*
* Implementers can declare support of contract interfaces, which can then be
* queried by others.
*
* For an implementation, see `KIP13`.
*/
interface IKIP13 {
/**
* @dev Returns true if this contract implements the interface defined by
* `interfaceId`. See the corresponding
* [KIP-13 section](http://kips.klaytn.com/KIPs/kip-13-interface_query_standard#how-interface-identifiers-are-defined)
* to learn more about how these ids are created.
*
* This function call must use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
/**
* @dev Implementation of the `IKIP13` interface.
*
* Contracts may inherit from this and call `_registerInterface` to declare
* their support of an interface.
*/
contract KIP13 is IKIP13 {
/*
* bytes4(keccak256('supportsInterface(bytes4)')) == 0x01ffc9a7
*/
bytes4 private constant _INTERFACE_ID_KIP13 = 0x01ffc9a7;
/**
* @dev Mapping of interface ids to whether or not it's supported.
*/
mapping(bytes4 => bool) private _supportedInterfaces;
constructor () internal {
// Derived contracts need only register support for their own interfaces,
// we register support for KIP13 itself here
_registerInterface(_INTERFACE_ID_KIP13);
}
/**
* @dev See `IKIP13.supportsInterface`.
*
* Time complexity O(1), guaranteed to always use less than 30 000 gas.
*/
function supportsInterface(bytes4 interfaceId) external view returns (bool) {
return _supportedInterfaces[interfaceId];
}
/**
* @dev Registers the contract as an implementer of the interface defined by
* `interfaceId`. Support of the actual KIP13 interface is automatic and
* registering its interface id is not required.
*
* See `IKIP13.supportsInterface`.
*
* Requirements:
*
* - `interfaceId` cannot be the KIP13 invalid interface (`0xffffffff`).
*/
function _registerInterface(bytes4 interfaceId) internal {
require(interfaceId != 0xffffffff, "KIP13: invalid interface id");
_supportedInterfaces[interfaceId] = true;
}
}
/**
* @dev Interface of the KIP7 standard as defined in the KIP. Does not include
* the optional functions; to access them see `KIP7Metadata`.
* See http://kips.klaytn.com/KIPs/kip-7-fungible_token
*/
contract IKIP7 is IKIP13 {
/**
* @dev Returns the amount of tokens in existence.
*/
function totalSupply() external view returns (uint256);
/**
* @dev Returns the amount of tokens owned by `account`.
*/
function balanceOf(address account) external view returns (uint256);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a `Transfer` event.
*/
function transfer(address recipient, uint256 amount) external returns (bool);
/**
* @dev Returns the remaining number of tokens that `spender` will be
* allowed to spend on behalf of `owner` through `transferFrom`. This is
* zero by default.
*
* This value changes when `approve` or `transferFrom` are called.
*/
function allowance(address owner, address spender) external view returns (uint256);
/**
* @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* > Beware that changing an allowance with this method brings the risk
* that someone may use both the old and the new allowance by unfortunate
* transaction ordering. One possible solution to mitigate this race
* condition is to first reduce the spender's allowance to 0 and set the
* desired value afterwards:
* https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
*
* Emits an `Approval` event.
*/
function approve(address spender, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism. `amount` is then deducted from the caller's
* allowance.
*
* Returns a boolean value indicating whether the operation succeeded.
*
* Emits a `Transfer` event.
*/
function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*/
function safeTransfer(address recipient, uint256 amount, bytes memory data) public;
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*/
function safeTransfer(address recipient, uint256 amount) public;
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the allowance mechanism.
* `amount` is then deducted from the caller's allowance.
*/
function safeTransferFrom(address sender, address recipient, uint256 amount, bytes memory data) public;
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the allowance mechanism.
* `amount` is then deducted from the caller's allowance.
*/
function safeTransferFrom(address sender, address recipient, uint256 amount) public;
/**
* @dev Emitted when `value` tokens are moved from one account (`from`) to
* another (`to`).
*
* Note that `value` may be zero.
*/
event Transfer(address indexed from, address indexed to, uint256 value);
/**
* @dev Emitted when the allowance of a `spender` for an `owner` is set by
* a call to `approve`. `value` is the new allowance.
*/
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @title KIP-7 Fungible Token Standard, optional wallet interface
* @dev Note: the KIP-13 identifier for this interface is 0x9d188c22.
* see http://kips.klaytn.com/KIPs/kip-7-fungible_token
*/
contract IKIP7Receiver {
/**
* @notice Handle the receipt of KIP-7 token
* @dev The KIP-7 smart contract calls this function on the recipient
* after a `safeTransfer`. This function MAY throw to revert and reject the
* transfer. Return of other than the magic value MUST result in the
* transaction being reverted.
* Note: the contract address is always the message sender.
* @param _operator The address which called `safeTransferFrom` function
* @param _from The address which previously owned the token
* @param _amount The token amount which is being transferred.
* @param _data Additional data with no specified format
* @return `bytes4(keccak256("onKIP7Received(address,address,uint256,bytes)"))`
* unless throwing
*/
function onKIP7Received(address _operator, address _from, uint256 _amount, bytes memory _data) public returns (bytes4);
}
/**
* @dev Implementation of the `IKIP7` interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using `_mint`.
* For a generic mechanism see `KIP7Mintable`.
*
* We have followed general OpenZeppelin guidelines: functions revert instead
* of returning `false` on failure. This behavior is nonetheless conventional
* and does not conflict with the expectations of KIP7 applications.
*
* Additionally, an `Approval` event is emitted on calls to `transferFrom`.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the KIP may not emit
* these events, as it isn't required by the specification.
*
* See http://kips.klaytn.com/KIPs/kip-7-fungible_token
*/
contract KIP7 is KIP13, IKIP7 {
using SafeMath for uint256;
using Address for address;
// Equals to `bytes4(keccak256("onKIP7Received(address,address,uint256,bytes)"))`
// which can be also obtained as `IKIP7Receiver(0).onKIP7Received.selector`
bytes4 private constant _KIP7_RECEIVED = 0x9d188c22;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowances;
uint256 private _totalSupply;
/*
* bytes4(keccak256('totalSupply()')) == 0x18160ddd
* bytes4(keccak256('balanceOf(address)')) == 0x70a08231
* bytes4(keccak256('transfer(address,uint256)')) == 0xa9059cbb
* bytes4(keccak256('allowance(address,address)')) == 0xdd62ed3e
* bytes4(keccak256('approve(address,uint256)')) == 0x095ea7b3
* bytes4(keccak256('transferFrom(address,address,uint256)')) == 0x23b872dd
* bytes4(keccak256("safeTransfer(address,uint256)")) == 0x423f6cef
* bytes4(keccak256("safeTransfer(address,uint256,bytes)")) == 0xeb795549
* bytes4(keccak256("safeTransferFrom(address,address,uint256)")) == 0x42842e0e
* bytes4(keccak256("safeTransferFrom(address,address,uint256,bytes)")) == 0xb88d4fde
*
* => 0x18160ddd ^ 0x70a08231 ^ 0xa9059cbb ^ 0xdd62ed3e ^ 0x095ea7b3 ^ 0x23b872dd ^ 0x423f6cef ^ 0xeb795549 ^ 0x42842e0e ^ 0xb88d4fde == 0x65787371
*/
bytes4 private constant _INTERFACE_ID_KIP7 = 0x65787371;
constructor () public {
// register the supported interfaces to conform to KIP7 via KIP13
_registerInterface(_INTERFACE_ID_KIP7);
}
/**
* @dev See `IKIP7.totalSupply`.
*/
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
/**
* @dev See `IKIP7.balanceOf`.
*/
function balanceOf(address account) public view returns (uint256) {
return _balances[account];
}
/**
* @dev See `IKIP7.transfer`.
*
* Requirements:
*
* - `recipient` cannot be the zero address.
* - the caller must have a balance of at least `amount`.
*/
function transfer(address recipient, uint256 amount) public returns (bool) {
_transfer(msg.sender, recipient, amount);
return true;
}
/**
* @dev See `IKIP7.allowance`.
*/
function allowance(address owner, address spender) public view returns (uint256) {
return _allowances[owner][spender];
}
/**
* @dev See `IKIP7.approve`.
*
* Requirements:
*
* - `spender` cannot be the zero address.
*/
function approve(address spender, uint256 value) public returns (bool) {
_approve(msg.sender, spender, value);
return true;
}
/**
* @dev See `IKIP7.transferFrom`.
*
* Emits an `Approval` event indicating the updated allowance. This is not
* required by the KIP. See the note at the beginning of `KIP7`;
*
* Requirements:
* - `sender` and `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `value`.
* - the caller must have allowance for `sender`'s tokens of at least
* `amount`.
*/
function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
_transfer(sender, recipient, amount);
_approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount));
return true;
}
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*/
function safeTransfer(address recipient, uint256 amount) public {
safeTransfer(recipient, amount, "");
}
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*/
function safeTransfer(address recipient, uint256 amount, bytes memory data) public {
transfer(recipient, amount);
require(_checkOnKIP7Received(msg.sender, recipient, amount, data), "KIP7: transfer to non KIP7Receiver implementer");
}
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the allowance mechanism.
* `amount` is then deducted from the caller's allowance.
*/
function safeTransferFrom(address sender, address recipient, uint256 amount) public {
safeTransferFrom(sender, recipient, amount, "");
}
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the allowance mechanism.
* `amount` is then deducted from the caller's allowance.
*/
function safeTransferFrom(address sender, address recipient, uint256 amount, bytes memory data) public {
transferFrom(sender, recipient, amount);
require(_checkOnKIP7Received(sender, recipient, amount, data), "KIP7: transfer to non KIP7Receiver implementer");
}
/**
* @dev Moves tokens `amount` from `sender` to `recipient`.
*
* This is internal function is equivalent to `transfer`, and can be used to
* e.g. implement automatic token fees, slashing mechanisms, etc.
*
* Emits a `Transfer` event.
*
* Requirements:
*
* - `sender` cannot be the zero address.
* - `recipient` cannot be the zero address.
* - `sender` must have a balance of at least `amount`.
*/
function _transfer(address sender, address recipient, uint256 amount) internal {
require(sender != address(0), "KIP7: transfer from the zero address");
require(recipient != address(0), "KIP7: transfer to the zero address");
_balances[sender] = _balances[sender].sub(amount);
_balances[recipient] = _balances[recipient].add(amount);
emit Transfer(sender, recipient, amount);
}
/** @dev Creates `amount` tokens and assigns them to `account`, increasing
* the total supply.
*
* Emits a `Transfer` event with `from` set to the zero address.
*
* Requirements
*
* - `to` cannot be the zero address.
*/
function _mint(address account, uint256 amount) internal {
require(account != address(0), "KIP7: mint to the zero address");
_totalSupply = _totalSupply.add(amount);
_balances[account] = _balances[account].add(amount);
emit Transfer(address(0), account, amount);
}
/**
* @dev Destroys `amount` tokens from `account`, reducing the
* total supply.
*
* Emits a `Transfer` event with `to` set to the zero address.
*
* Requirements
*
* - `account` cannot be the zero address.
* - `account` must have at least `amount` tokens.
*/
function _burn(address account, uint256 value) internal {
require(account != address(0), "KIP7: burn from the zero address");
_totalSupply = _totalSupply.sub(value);
_balances[account] = _balances[account].sub(value);
emit Transfer(account, address(0), value);
}
/**
* @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
*
* This internal function is equivalent to `approve`, and can be used to
* e.g. set automatic allowances for certain subsystems, etc.
*
* Emits an `Approval` event.
*
* Requirements:
*
* - `owner` cannot be the zero address.
* - `spender` cannot be the zero address.
*/
function _approve(address owner, address spender, uint256 value) internal {
require(owner != address(0), "KIP7: approve from the zero address");
require(spender != address(0), "KIP7: approve to the zero address");
_allowances[owner][spender] = value;
emit Approval(owner, spender, value);
}
/**
* @dev Destroys `amount` tokens from `account`.`amount` is then deducted
* from the caller's allowance.
*
* See `_burn` and `_approve`.
*/
function _burnFrom(address account, uint256 amount) internal {
_burn(account, amount);
_approve(account, msg.sender, _allowances[account][msg.sender].sub(amount));
}
/**
* @dev Internal function to invoke `onKIP7Received` on a target address.
* The call is not executed if the target address is not a contract.
*/
function _checkOnKIP7Received(address sender, address recipient, uint256 amount, bytes memory _data)
internal returns (bool)
{
if (!recipient.isContract()) {
return true;
}
bytes4 retval = IKIP7Receiver(recipient).onKIP7Received(msg.sender, sender, amount, _data);
return (retval == _KIP7_RECEIVED);
}
}
/**
* @dev Extension of `KIP7` that allows token holders to destroy both their own
* tokens and those that they have an allowance for, in a way that can be
* recognized off-chain (via event analysis).
*
* See http://kips.klaytn.com/KIPs/kip-7-fungible_token
*/
contract KIP7Burnable is KIP13, KIP7 {
/*
* bytes4(keccak256('burn(uint256)')) == 0x42966c68
* bytes4(keccak256('burnFrom(address,uint256)')) == 0x79cc6790
*
* => 0x42966c68 ^ 0x79cc6790 == 0x3b5a0bf8
*/
bytes4 private constant _INTERFACE_ID_KIP7BURNABLE = 0x3b5a0bf8;
constructor () public {
// register the supported interfaces to conform to KIP17 via KIP13
_registerInterface(_INTERFACE_ID_KIP7BURNABLE);
}
/**
* @dev Destroys `amount` tokens from the caller.
*
* See `KIP7._burn`.
*/
function burn(uint256 amount) public {
_burn(msg.sender, amount);
}
/**
* @dev See `KIP7._burnFrom`.
*/
function burnFrom(address account, uint256 amount) public {
_burnFrom(account, amount);
}
}
/**
* @dev Optional functions from the KIP7 standard.
* See http://kips.klaytn.com/KIPs/kip-7-fungible_token
*/
contract KIP7Metadata is KIP13, IKIP7 {
string private _name;
string private _symbol;
uint8 private _decimals;
/*
* bytes4(keccak256('name()')) == 0x06fdde03
* bytes4(keccak256('symbol()')) == 0x95d89b41
* bytes4(keccak256('decimals()')) == 0x313ce567
*
* => 0x06fdde03 ^ 0x95d89b41 ^ 0x313ce567 == 0xa219a025
*/
bytes4 private constant _INTERFACE_ID_KIP7_METADATA = 0xa219a025;
/**
* @dev Sets the values for `name`, `symbol`, and `decimals`. All three of
* these values are immutable: they can only be set once during
* construction.
*/
constructor (string memory name, string memory symbol, uint8 decimals) public {
_name = name;
_symbol = symbol;
_decimals = decimals;
// register the supported interfaces to conform to KIP7 via KIP13
_registerInterface(_INTERFACE_ID_KIP7_METADATA);
}
/**
* @dev Returns the name of the token.
*/
function name() public view returns (string memory) {
return _name;
}
/**
* @dev Returns the symbol of the token, usually a shorter version of the
* name.
*/
function symbol() public view returns (string memory) {
return _symbol;
}
/**
* @dev Returns the number of decimals used to get its user representation.
* For example, if `decimals` equals `2`, a balance of `505` tokens should
* be displayed to a user as `5,05` (`505 / 10 ** 2`).
*
* Tokens usually opt for a value of 18, imitating the relationship between
* Ether and Wei.
*
* > Note that this information is only used for _display_ purposes: it in
* no way affects any of the arithmetic of the contract, including
* `IKIP7.balanceOf` and `IKIP7.transfer`.
*/
function decimals() public view returns (uint8) {
return _decimals;
}
}
contract PauserRole {
using Roles for Roles.Role;
event PauserAdded(address indexed account);
event PauserRemoved(address indexed account);
Roles.Role private _pausers;
constructor () internal {
_addPauser(msg.sender);
}
modifier onlyPauser() {
require(isPauser(msg.sender), "PauserRole: caller does not have the Pauser role");
_;
}
function isPauser(address account) public view returns (bool) {
return _pausers.has(account);
}
function addPauser(address account) public onlyPauser {
_addPauser(account);
}
function renouncePauser() public {
_removePauser(msg.sender);
}
function _addPauser(address account) internal {
_pausers.add(account);
emit PauserAdded(account);
}
function _removePauser(address account) internal {
_pausers.remove(account);
emit PauserRemoved(account);
}
}
/**
* @dev Contract module which allows children to implement an emergency stop
* mechanism that can be triggered by an authorized account.
*
* This module is used through inheritance. It will make available the
* modifiers `whenNotPaused` and `whenPaused`, which can be applied to
* the functions of your contract. Note that they will not be pausable by
* simply including this module, only once the modifiers are put in place.
*/
contract Pausable is PauserRole {
/**
* @dev Emitted when the pause is triggered by a pauser (`account`).
*/
event Paused(address account);
/**
* @dev Emitted when the pause is lifted by a pauser (`account`).
*/
event Unpaused(address account);
bool private _paused;
/**
* @dev Initializes the contract in unpaused state. Assigns the Pauser role
* to the deployer.
*/
constructor () internal {
_paused = false;
}
/**
* @dev Returns true if the contract is paused, and false otherwise.
*/
function paused() public view returns (bool) {
return _paused;
}
/**
* @dev Modifier to make a function callable only when the contract is not paused.
*/
modifier whenNotPaused() {
require(!_paused, "Pausable: paused");
_;
}
/**
* @dev Modifier to make a function callable only when the contract is paused.
*/
modifier whenPaused() {
require(_paused, "Pausable: not paused");
_;
}
/**
* @dev Called by a pauser to pause, triggers stopped state.
*/
function pause() public onlyPauser whenNotPaused {
_paused = true;
emit Paused(msg.sender);
}
/**
* @dev Called by a pauser to unpause, returns to normal state.
*/
function unpause() public onlyPauser whenPaused {
_paused = false;
emit Unpaused(msg.sender);
}
}
/**
* @title Pausable token
* @dev KIP7 modified with pausable transfers.
* See http://kips.klaytn.com/KIPs/kip-7-fungible_token
*/
contract KIP7Pausable is KIP13, KIP7, Pausable {
/*
* bytes4(keccak256('paused()')) == 0x5c975abb
* bytes4(keccak256('pause()')) == 0x8456cb59
* bytes4(keccak256('unpause()')) == 0x3f4ba83a
* bytes4(keccak256('isPauser(address)')) == 0x46fbf68e
* bytes4(keccak256('addPauser(address)')) == 0x82dc1ec4
* bytes4(keccak256('renouncePauser()')) == 0x6ef8d66d
*
* => 0x5c975abb ^ 0x8456cb59 ^ 0x3f4ba83a ^ 0x46fbf68e ^ 0x82dc1ec4 ^ 0x6ef8d66d == 0x4d5507ff
*/
bytes4 private constant _INTERFACE_ID_KIP7PAUSABLE = 0x4d5507ff;
constructor () public {
// register the supported interfaces to conform to KIP17 via KIP13
_registerInterface(_INTERFACE_ID_KIP7PAUSABLE);
}
function transfer(address to, uint256 value) public whenNotPaused returns (bool) {
return super.transfer(to, value);
}
function transferFrom(address from, address to, uint256 value) public whenNotPaused returns (bool) {
return super.transferFrom(from, to, value);
}
function approve(address spender, uint256 value) public whenNotPaused returns (bool) {
return super.approve(spender, value);
}
}
/**
* @title MyToken
* @dev KIP7 based Blue Point Token, where all tokens are pre-assigned to the creator.
* @dev Not Mintable Token.
*/
contract MyToken is KIP7Burnable, KIP7Pausable, KIP7Metadata {
/**
* @dev Constructor that gives msg.sender(owner) all of existing tokens.
*/
constructor () public KIP7Metadata("MyToken", "MYTOKEN", 18) {
_mint(msg.sender, 100 * (10 ** uint256(decimals())));
}
/**
* @dev Throws if sender is not authorized
* Owner is always passed. And other accounts should be unpaused.
*/
modifier isTradable(address sender){
require(!isPauser(sender), "MyToken: Not Tradable");
_;
}
/**
* @dev Moves `amount` tokens from the caller's account to `recipient`.
*
* isTradable is applied
*/
function transfer(address to, uint256 value) public isTradable(msg.sender) returns (bool) {
return super.transfer(to, value);
}
/**
* @dev Moves `amount` tokens from `sender` to `recipient` using the
* allowance mechanism.
* isTradable is applied.
*/
function transferFrom(address from, address to, uint256 value) public isTradable(from) returns (bool) {
return super.transferFrom(from, to, value);
}
/**
* @dev Destroys `amount` tokens from the caller.
*
* isTradable is applied
*/
function burn(uint256 amount) public isTradable(msg.sender) {
_burn(msg.sender, amount);
}
}안녕하세요, 에러는
MyToken: Not Tradable
요렇게 나오는데, isTradable()함수를 확인해보셔야 할 것 같습니다.
네, 실수였습니다.
답변 감사합니다. 