Theta Smart Contracts | ThetaScan.io

Node:

Token Contract Details

Contract:

0x60fa3179a69f5720b6f988f508d69a8f473cbcc8

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

Published Contract:

pragma solidity ^0.5.0; // compiled with: v0.5.6+commit.b259423e

// https://github.com/OpenZeppelin/openzeppelin-solidity/blob/v2.3.0/contracts/utils/Address.sol
/**
 * @dev Collection of functions related to the address type,
 */
library Address {
 /**
 * @dev Returns true if `account` is a contract.
 *
 * This test is non-exhaustive, and there may be false-negatives: during the
 * execution of a contract9s constructor, its address will be reported as
 * not containing a contract.
 *
 * > It is unsafe to assume that an address for which this function returns
 * false is an externally-owned account (EOA) and not a contract.
 */
 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;
 }
}

// https://github.com/OpenZeppelin/openzeppelin-solidity/blob/v2.3.0/contracts/math/SafeMath.sol
/**
 * @dev Wrappers over Solidity9s arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it9s recommended to use it always.
 */
library SafeMath {
 /**
 * @dev Returns the addition of two unsigned integers, reverting on
 * overflow.
 *
 * Counterpart to Solidity9s `+` operator.
 *
 * Requirements:
 * - Addition cannot overflow.
 */
 function add(uint256 a, uint256 b) internal pure returns (uint256) {
 uint256 c = a + b;
 require(c >= a, "SafeMath: addition overflow");

 return c;
 }

 /**
 * @dev Returns the subtraction of two unsigned integers, reverting on
 * overflow (when the result is negative).
 *
 * Counterpart to Solidity9s `-` operator.
 *
 * Requirements:
 * - Subtraction cannot overflow.
 */
 function sub(uint256 a, uint256 b) internal pure returns (uint256) {
 require(b <= a, "SafeMath: subtraction overflow");
 uint256 c = a - b;

 return c;
 }

 /**
 * @dev Returns the multiplication of two unsigned integers, reverting on
 * overflow.
 *
 * Counterpart to Solidity9s `*` operator.
 *
 * Requirements:
 * - Multiplication cannot overflow.
 */
 function mul(uint256 a, uint256 b) internal pure returns (uint256) {
 // Gas optimization: this is cheaper than requiring 9a9 not being zero, but the
 // benefit is lost if 9b9 is also tested.
 // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
 if (a == 0) {
 return 0;
 }

 uint256 c = a * b;
 require(c / a == b, "SafeMath: multiplication overflow");

 return c;
 }

 /**
 * @dev Returns the integer division of two unsigned integers. Reverts on
 * division by zero. The result is rounded towards zero.
 *
 * Counterpart to Solidity9s `/` operator. Note: this function uses a
 * `revert` opcode (which leaves remaining gas untouched) while Solidity
 * uses an invalid opcode to revert (consuming all remaining gas).
 *
 * Requirements:
 * - The divisor cannot be zero.
 */
 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 doesn9t hold

 return c;
 }

 /**
 * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
 * Reverts when dividing by zero.
 *
 * Counterpart to Solidity9s `%` operator. This function uses a `revert`
 * opcode (which leaves remaining gas untouched) while Solidity uses an
 * invalid opcode to revert (consuming all remaining gas).
 *
 * Requirements:
 * - The divisor cannot be zero.
 */
 function mod(uint256 a, uint256 b) internal pure returns (uint256) {
 require(b != 0, "SafeMath: modulo by zero");
 return a % b;
 }
}

// https://github.com/OpenZeppelin/openzeppelin-solidity/blob/v2.3.0/contracts/drafts/Counters.sol
/**
 * @title Counters
 * @author Matt Condon (@shrugs)
 * @dev Provides counters that can only be incremented or decremented by one. This can be used e.g. to track the number
 * of elements in a mapping, issuing ERC721 ids, or counting request ids.
 *
 * Include with `using Counters for Counters.Counter;`
 * Since it is not possible to overflow a 256 bit integer with increments of one, `increment` can skip the SafeMath
 * overflow check, thereby saving gas. This does assume however correct usage, in that the underlying `_value` is never
 * directly accessed.
 */
library Counters {
 using SafeMath for uint256;

 struct Counter {
 // This variable should never be directly accessed by users of the library: interactions must be restricted to
 // the library9s function. As of Solidity v0.5.2, this cannot be enforced, though there is a proposal to add
 // this feature: see https://github.com/ethereum/solidity/issues/4637
 uint256 _value; // default: 0
 }

 function current(Counter storage counter) internal view returns (uint256) {
 return counter._value;
 }

 function increment(Counter storage counter) internal {
 counter._value += 1;
 }

 function decrement(Counter storage counter) internal {
 counter._value = counter._value.sub(1);
 }
}

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * [EIP](https://eips.ethereum.org/EIPS/eip-165).
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others (`ERC165Checker`).
 *
 * For an implementation, see `ERC165`.
 */
interface IERC165 {
 /**
 * @dev Returns true if this contract implements the interface defined by
 * `interfaceId`. See the corresponding
 * [EIP section](https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified)
 * 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 `IERC165` interface.
 *
 * Contracts may inherit from this and call `_registerInterface` to declare
 * their support of an interface.
 */
contract ERC165 is IERC165 {
 /*
 * bytes4(keccak256(9supportsInterface(bytes4)9)) == 0x01ffc9a7
 */
 bytes4 private constant _INTERFACE_ID_ERC165 = 0x01ffc9a7;

 /**
 * @dev Mapping of interface ids to whether or not it9s supported.
 */
 mapping(bytes4 => bool) private _supportedInterfaces;

 constructor () internal {
 // Derived contracts need only register support for their own interfaces,
 // we register support for ERC165 itself here
 _registerInterface(_INTERFACE_ID_ERC165);
 }

 /**
 * @dev See `IERC165.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 ERC165 interface is automatic and
 * registering its interface id is not required.
 *
 * See `IERC165.supportsInterface`.
 *
 * Requirements:
 *
 * - `interfaceId` cannot be the ERC165 invalid interface (`0xffffffff`).
 */
 function _registerInterface(bytes4 interfaceId) internal {
 require(interfaceId != 0xffffffff, "ERC165: invalid interface id");
 _supportedInterfaces[interfaceId] = true;
 }
}

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
contract IERC721 is IERC165 {
 event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);
 event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);
 event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

 /**
 * @dev Returns the number of NFTs in `owner`9s account.
 */
 function balanceOf(address owner) public view returns (uint256 balance);

 /**
 * @dev Returns the owner of the NFT specified by `tokenId`.
 */
 function ownerOf(uint256 tokenId) public view returns (address owner);

 /**
 * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
 * another (`to`).
 *
 *
 *
 * Requirements:
 * - `from`, `to` cannot be zero.
 * - `tokenId` must be owned by `from`.
 * - If the caller is not `from`, it must be have been allowed to move this
 * NFT by either `approve` or `setApproveForAll`.
 */
 function safeTransferFrom(address from, address to, uint256 tokenId) public;
 /**
 * @dev Transfers a specific NFT (`tokenId`) from one account (`from`) to
 * another (`to`).
 *
 * Requirements:
 * - If the caller is not `from`, it must be approved to move this NFT by
 * either `approve` or `setApproveForAll`.
 */
 function transferFrom(address from, address to, uint256 tokenId) public;
 function approve(address to, uint256 tokenId) public;
 function getApproved(uint256 tokenId) public view returns (address operator);

 function setApprovalForAll(address operator, bool _approved) public;
 function isApprovedForAll(address owner, address operator) public view returns (bool);


 function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory data) public;
}

// https://github.com/OpenZeppelin/openzeppelin-solidity/blob/v2.3.0/contracts/token/ERC721/IERC721Receiver.sol
/**
 * @title ERC721 token receiver interface
 * @dev Interface for any contract that wants to support safeTransfers
 * from ERC721 asset contracts.
 */
contract IERC721Receiver {
 /**
 * @notice Handle the receipt of an NFT
 * @dev The ERC721 smart contract calls this function on the recipient
 * after a `safeTransfer`. This function MUST return the function selector,
 * otherwise the caller will revert the transaction. The selector to be
 * returned can be obtained as `this.onERC721Received.selector`. This
 * function MAY throw to revert and reject the transfer.
 * Note: the ERC721 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 tokenId The NFT identifier which is being transferred
 * @param data Additional data with no specified format
 * @return bytes4 `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
 */
 function onERC721Received(address operator, address from, uint256 tokenId, bytes memory data)
 public returns (bytes4);
}

// https://github.com/OpenZeppelin/openzeppelin-solidity/blob/v2.3.0/contracts/token/ERC721/ERC721.sol
contract ERC721 is ERC165, IERC721 {
 using SafeMath for uint256;
 using Address for address;
 using Counters for Counters.Counter;

 // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
 // which can be also obtained as `IERC721Receiver(0).onERC721Received.selector`
 bytes4 private constant _ERC721_RECEIVED = 0x150b7a02;

 // Mapping from token ID to owner
 mapping (uint256 => address) private _tokenOwner;

 // Mapping from token ID to approved address
 mapping (uint256 => address) private _tokenApprovals;

 // Mapping from owner to number of owned token
 mapping (address => Counters.Counter) private _ownedTokensCount;

 // Mapping from owner to operator approvals
 mapping (address => mapping (address => bool)) private _operatorApprovals;

 /*
 * bytes4(keccak256(9balanceOf(address)9)) == 0x70a08231
 * bytes4(keccak256(9ownerOf(uint256)9)) == 0x6352211e
 * bytes4(keccak256(9approve(address,uint256)9)) == 0x095ea7b3
 * bytes4(keccak256(9getApproved(uint256)9)) == 0x081812fc
 * bytes4(keccak256(9setApprovalForAll(address,bool)9)) == 0xa22cb465
 * bytes4(keccak256(9isApprovedForAll(address,address)9)) == 0xe985e9c
 * bytes4(keccak256(9transferFrom(address,address,uint256)9)) == 0x23b872dd
 * bytes4(keccak256(9safeTransferFrom(address,address,uint256)9)) == 0x42842e0e
 * bytes4(keccak256(9safeTransferFrom(address,address,uint256,bytes)9)) == 0xb88d4fde
 *
 * => 0x70a08231 ^ 0x6352211e ^ 0x095ea7b3 ^ 0x081812fc ^
 * 0xa22cb465 ^ 0xe985e9c ^ 0x23b872dd ^ 0x42842e0e ^ 0xb88d4fde == 0x80ac58cd
 */
 bytes4 private constant _INTERFACE_ID_ERC721 = 0x80ac58cd;

 constructor () public {
 // register the supported interfaces to conform to ERC721 via ERC165
 _registerInterface(_INTERFACE_ID_ERC721);
 }

 /**
 * @dev Gets the balance of the specified address.
 * @param owner address to query the balance of
 * @return uint256 representing the amount owned by the passed address
 */
 function balanceOf(address owner) public view returns (uint256) {
 require(owner != address(0), "ERC721: balance query for the zero address");

 return _ownedTokensCount[owner].current();
 }

 /**
 * @dev Gets the owner of the specified token ID.
 * @param tokenId uint256 ID of the token to query the owner of
 * @return address currently marked as the owner of the given token ID
 */
 function ownerOf(uint256 tokenId) public view returns (address) {
 address owner = _tokenOwner[tokenId];
 require(owner != address(0), "ERC721: owner query for nonexistent token");

 return owner;
 }

 /**
 * @dev Approves another address to transfer the given token ID
 * The zero address indicates there is no approved address.
 * There can only be one approved address per token at a given time.
 * Can only be called by the token owner or an approved operator.
 * @param to address to be approved for the given token ID
 * @param tokenId uint256 ID of the token to be approved
 */
 function approve(address to, uint256 tokenId) public {
 address owner = ownerOf(tokenId);
 require(to != owner, "ERC721: approval to current owner");

 require(msg.sender == owner || isApprovedForAll(owner, msg.sender),
 "ERC721: approve caller is not owner nor approved for all"
 );

 _tokenApprovals[tokenId] = to;
 emit Approval(owner, to, tokenId);
 }

 /**
 * @dev Gets the approved address for a token ID, or zero if no address set
 * Reverts if the token ID does not exist.
 * @param tokenId uint256 ID of the token to query the approval of
 * @return address currently approved for the given token ID
 */
 function getApproved(uint256 tokenId) public view returns (address) {
 require(_exists(tokenId), "ERC721: approved query for nonexistent token");

 return _tokenApprovals[tokenId];
 }

 /**
 * @dev Sets or unsets the approval of a given operator
 * An operator is allowed to transfer all tokens of the sender on their behalf.
 * @param to operator address to set the approval
 * @param approved representing the status of the approval to be set
 */
 function setApprovalForAll(address to, bool approved) public {
 require(to != msg.sender, "ERC721: approve to caller");

 _operatorApprovals[msg.sender][to] = approved;
 emit ApprovalForAll(msg.sender, to, approved);
 }

 /**
 * @dev Tells whether an operator is approved by a given owner.
 * @param owner owner address which you want to query the approval of
 * @param operator operator address which you want to query the approval of
 * @return bool whether the given operator is approved by the given owner
 */
 function isApprovedForAll(address owner, address operator) public view returns (bool) {
 return _operatorApprovals[owner][operator];
 }

 /**
 * @dev Transfers the ownership of a given token ID to another address.
 * Usage of this method is discouraged, use `safeTransferFrom` whenever possible.
 * Requires the msg.sender to be the owner, approved, or operator.
 * @param from current owner of the token
 * @param to address to receive the ownership of the given token ID
 * @param tokenId uint256 ID of the token to be transferred
 */
 function transferFrom(address from, address to, uint256 tokenId) public {
 //solhint-disable-next-line max-line-length
 require(_isApprovedOrOwner(msg.sender, tokenId), "ERC721: transfer caller is not owner nor approved");

 _transferFrom(from, to, tokenId);
 }

 /**
 * @dev Safely transfers the ownership of a given token ID to another address
 * If the target address is a contract, it must implement `onERC721Received`,
 * which is called upon a safe transfer, and return the magic value
 * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
 * the transfer is reverted.
 * Requires the msg.sender to be the owner, approved, or operator
 * @param from current owner of the token
 * @param to address to receive the ownership of the given token ID
 * @param tokenId uint256 ID of the token to be transferred
 */
 function safeTransferFrom(address from, address to, uint256 tokenId) public {
 safeTransferFrom(from, to, tokenId, "");
 }

 /**
 * @dev Safely transfers the ownership of a given token ID to another address
 * If the target address is a contract, it must implement `onERC721Received`,
 * which is called upon a safe transfer, and return the magic value
 * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
 * the transfer is reverted.
 * Requires the msg.sender to be the owner, approved, or operator
 * @param from current owner of the token
 * @param to address to receive the ownership of the given token ID
 * @param tokenId uint256 ID of the token to be transferred
 * @param _data bytes data to send along with a safe transfer check
 */
 function safeTransferFrom(address from, address to, uint256 tokenId, bytes memory _data) public {
 transferFrom(from, to, tokenId);
 require(_checkOnERC721Received(from, to, tokenId, _data), "ERC721: transfer to non ERC721Receiver implementer");
 }

 /**
 * @dev Returns whether the specified token exists.
 * @param tokenId uint256 ID of the token to query the existence of
 * @return bool whether the token exists
 */
 function _exists(uint256 tokenId) internal view returns (bool) {
 address owner = _tokenOwner[tokenId];
 return owner != address(0);
 }

 /**
 * @dev Returns whether the given spender can transfer a given token ID.
 * @param spender address of the spender to query
 * @param tokenId uint256 ID of the token to be transferred
 * @return bool whether the msg.sender is approved for the given token ID,
 * is an operator of the owner, or is the owner of the token
 */
 function _isApprovedOrOwner(address spender, uint256 tokenId) internal view returns (bool) {
 require(_exists(tokenId), "ERC721: operator query for nonexistent token");
 address owner = ownerOf(tokenId);
 return (spender == owner || getApproved(tokenId) == spender || isApprovedForAll(owner, spender));
 }

 /**
 * @dev Internal function to mint a new token.
 * Reverts if the given token ID already exists.
 * @param to The address that will own the minted token
 * @param tokenId uint256 ID of the token to be minted
 */
 function _mint(address to, uint256 tokenId) internal {
 require(to != address(0), "ERC721: mint to the zero address");
 require(!_exists(tokenId), "ERC721: token already minted");

 _tokenOwner[tokenId] = to;
 _ownedTokensCount[to].increment();

 emit Transfer(address(0), to, tokenId);
 }

 /**
 * @dev Internal function to burn a specific token.
 * Reverts if the token does not exist.
 * Deprecated, use _burn(uint256) instead.
 * @param owner owner of the token to burn
 * @param tokenId uint256 ID of the token being burned
 */
 function _burn(address owner, uint256 tokenId) internal {
 require(ownerOf(tokenId) == owner, "ERC721: burn of token that is not own");

 _clearApproval(tokenId);

 _ownedTokensCount[owner].decrement();
 _tokenOwner[tokenId] = address(0);

 emit Transfer(owner, address(0), tokenId);
 }

 /**
 * @dev Internal function to burn a specific token.
 * Reverts if the token does not exist.
 * @param tokenId uint256 ID of the token being burned
 */
 function _burn(uint256 tokenId) internal {
 _burn(ownerOf(tokenId), tokenId);
 }

 /**
 * @dev Internal function to transfer ownership of a given token ID to another address.
 * As opposed to transferFrom, this imposes no restrictions on msg.sender.
 * @param from current owner of the token
 * @param to address to receive the ownership of the given token ID
 * @param tokenId uint256 ID of the token to be transferred
 */
 function _transferFrom(address from, address to, uint256 tokenId) internal {
 require(ownerOf(tokenId) == from, "ERC721: transfer of token that is not own");
 require(to != address(0), "ERC721: transfer to the zero address");

 _clearApproval(tokenId);

 _ownedTokensCount[from].decrement();
 _ownedTokensCount[to].increment();

 _tokenOwner[tokenId] = to;

 emit Transfer(from, to, tokenId);
 }

 /**
 * @dev Internal function to invoke `onERC721Received` on a target address.
 * The call is not executed if the target address is not a contract.
 *
 * This function is deprecated.
 * @param from address representing the previous owner of the given token ID
 * @param to target address that will receive the tokens
 * @param tokenId uint256 ID of the token to be transferred
 * @param _data bytes optional data to send along with the call
 * @return bool whether the call correctly returned the expected magic value
 */
 function _checkOnERC721Received(address from, address to, uint256 tokenId, bytes memory _data)
 internal returns (bool)
 {
 if (!to.isContract()) {
 return true;
 }

 bytes4 retval = IERC721Receiver(to).onERC721Received(msg.sender, from, tokenId, _data);
 return (retval == _ERC721_RECEIVED);
 }

 /**
 * @dev Private function to clear current approval of a given token ID.
 * @param tokenId uint256 ID of the token to be transferred
 */
 function _clearApproval(uint256 tokenId) private {
 if (_tokenApprovals[tokenId] != address(0)) {
 _tokenApprovals[tokenId] = address(0);
 }
 }
}

/**
 * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
contract IERC721Enumerable is IERC721 {
 function totalSupply() public view returns (uint256);
 function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256 tokenId);

 function tokenByIndex(uint256 index) public view returns (uint256);
}

/**
 * @title ERC-721 Non-Fungible Token with optional enumeration extension logic
 * @dev See https://eips.ethereum.org/EIPS/eip-721
 */
contract ERC721Enumerable is ERC165, ERC721, IERC721Enumerable {
 // Mapping from owner to list of owned token IDs
 mapping(address => uint256[]) private _ownedTokens;

 // Mapping from token ID to index of the owner tokens list
 mapping(uint256 => uint256) private _ownedTokensIndex;

 // Array with all token ids, used for enumeration
 uint256[] private _allTokens;

 // Mapping from token id to position in the allTokens array
 mapping(uint256 => uint256) private _allTokensIndex;

 /*
 * bytes4(keccak256(9totalSupply()9)) == 0x18160ddd
 * bytes4(keccak256(9tokenOfOwnerByIndex(address,uint256)9)) == 0x2f745c59
 * bytes4(keccak256(9tokenByIndex(uint256)9)) == 0x4f6ccce7
 *
 * => 0x18160ddd ^ 0x2f745c59 ^ 0x4f6ccce7 == 0x780e9d63
 */
 bytes4 private constant _INTERFACE_ID_ERC721_ENUMERABLE = 0x780e9d63;

 /**
 * @dev Constructor function.
 */
 constructor () public {
 // register the supported interface to conform to ERC721Enumerable via ERC165
 _registerInterface(_INTERFACE_ID_ERC721_ENUMERABLE);
 }

 /**
 * @dev Gets the token ID at a given index of the tokens list of the requested owner.
 * @param owner address owning the tokens list to be accessed
 * @param index uint256 representing the index to be accessed of the requested tokens list
 * @return uint256 token ID at the given index of the tokens list owned by the requested address
 */
 function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {
 require(index < balanceOf(owner), "ERC721Enumerable: owner index out of bounds");
 return _ownedTokens[owner][index];
 }

 /**
 * @dev Gets the total amount of tokens stored by the contract.
 * @return uint256 representing the total amount of tokens
 */
 function totalSupply() public view returns (uint256) {
 return _allTokens.length;
 }

 /**
 * @dev Gets the token ID at a given index of all the tokens in this contract
 * Reverts if the index is greater or equal to the total number of tokens.
 * @param index uint256 representing the index to be accessed of the tokens list
 * @return uint256 token ID at the given index of the tokens list
 */
 function tokenByIndex(uint256 index) public view returns (uint256) {
 require(index < totalSupply(), "ERC721Enumerable: global index out of bounds");
 return _allTokens[index];
 }

 /**
 * @dev Internal function to transfer ownership of a given token ID to another address.
 * As opposed to transferFrom, this imposes no restrictions on msg.sender.
 * @param from current owner of the token
 * @param to address to receive the ownership of the given token ID
 * @param tokenId uint256 ID of the token to be transferred
 */
 function _transferFrom(address from, address to, uint256 tokenId) internal {
 super._transferFrom(from, to, tokenId);

 _removeTokenFromOwnerEnumeration(from, tokenId);

 _addTokenToOwnerEnumeration(to, tokenId);
 }

 /**
 * @dev Internal function to mint a new token.
 * Reverts if the given token ID already exists.
 * @param to address the beneficiary that will own the minted token
 * @param tokenId uint256 ID of the token to be minted
 */
 function _mint(address to, uint256 tokenId) internal {
 super._mint(to, tokenId);

 _addTokenToOwnerEnumeration(to, tokenId);

 _addTokenToAllTokensEnumeration(tokenId);
 }

 /**
 * @dev Internal function to burn a specific token.
 * Reverts if the token does not exist.
 * Deprecated, use _burn(uint256) instead.
 * @param owner owner of the token to burn
 * @param tokenId uint256 ID of the token being burned
 */
 function _burn(address owner, uint256 tokenId) internal {
 super._burn(owner, tokenId);

 _removeTokenFromOwnerEnumeration(owner, tokenId);
 // Since tokenId will be deleted, we can clear its slot in _ownedTokensIndex to trigger a gas refund
 _ownedTokensIndex[tokenId] = 0;

 _removeTokenFromAllTokensEnumeration(tokenId);
 }

 /**
 * @dev Gets the list of token IDs of the requested owner.
 * @param owner address owning the tokens
 * @return uint256[] List of token IDs owned by the requested address
 */
 function _tokensOfOwner(address owner) internal view returns (uint256[] storage) {
 return _ownedTokens[owner];
 }

 /**
 * @dev Private function to add a token to this extension9s ownership-tracking data structures.
 * @param to address representing the new owner of the given token ID
 * @param tokenId uint256 ID of the token to be added to the tokens list of the given address
 */
 function _addTokenToOwnerEnumeration(address to, uint256 tokenId) private {
 _ownedTokensIndex[tokenId] = _ownedTokens[to].length;
 _ownedTokens[to].push(tokenId);
 }

 /**
 * @dev Private function to add a token to this extension9s token tracking data structures.
 * @param tokenId uint256 ID of the token to be added to the tokens list
 */
 function _addTokenToAllTokensEnumeration(uint256 tokenId) private {
 _allTokensIndex[tokenId] = _allTokens.length;
 _allTokens.push(tokenId);
 }

 /**
 * @dev Private function to remove a token from this extension9s ownership-tracking data structures. Note that
 * while the token is not assigned a new owner, the _ownedTokensIndex mapping is _not_ updated: this allows for
 * gas optimizations e.g. when performing a transfer operation (avoiding double writes).
 * This has O(1) time complexity, but alters the order of the _ownedTokens array.
 * @param from address representing the previous owner of the given token ID
 * @param tokenId uint256 ID of the token to be removed from the tokens list of the given address
 */
 function _removeTokenFromOwnerEnumeration(address from, uint256 tokenId) private {
 // To prevent a gap in from9s tokens array, we store the last token in the index of the token to delete, and
 // then delete the last slot (swap and pop).

 uint256 lastTokenIndex = _ownedTokens[from].length.sub(1);
 uint256 tokenIndex = _ownedTokensIndex[tokenId];

 // When the token to delete is the last token, the swap operation is unnecessary
 if (tokenIndex != lastTokenIndex) {
 uint256 lastTokenId = _ownedTokens[from][lastTokenIndex];

 _ownedTokens[from][tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
 _ownedTokensIndex[lastTokenId] = tokenIndex; // Update the moved token9s index
 }

 // This also deletes the contents at the last position of the array
 _ownedTokens[from].length--;

 // Note that _ownedTokensIndex[tokenId] hasn9t been cleared: it still points to the old slot (now occupied by
 // lastTokenId, or just over the end of the array if the token was the last one).
 }

 /**
 * @dev Private function to remove a token from this extension9s token tracking data structures.
 * This has O(1) time complexity, but alters the order of the _allTokens array.
 * @param tokenId uint256 ID of the token to be removed from the tokens list
 */
 function _removeTokenFromAllTokensEnumeration(uint256 tokenId) private {
 // To prevent a gap in the tokens array, we store the last token in the index of the token to delete, and
 // then delete the last slot (swap and pop).

 uint256 lastTokenIndex = _allTokens.length.sub(1);
 uint256 tokenIndex = _allTokensIndex[tokenId];

 // When the token to delete is the last token, the swap operation is unnecessary. However, since this occurs so
 // rarely (when the last minted token is burnt) that we still do the swap here to avoid the gas cost of adding
 // an 9if9 statement (like in _removeTokenFromOwnerEnumeration)
 uint256 lastTokenId = _allTokens[lastTokenIndex];

 _allTokens[tokenIndex] = lastTokenId; // Move the last token to the slot of the to-delete token
 _allTokensIndex[lastTokenId] = tokenIndex; // Update the moved token9s index

 // This also deletes the contents at the last position of the array
 _allTokens.length--;
 _allTokensIndex[tokenId] = 0;
 }
}

contract TNT721 is ERC721Enumerable {

 struct Instance {
 // the owner of the contract at the time the token was minted
 address minter;
 // the original account the token was minted to
 address original_owner;
 // the id given to the token off chain
 string off_chain_id;
 }

 // the original creator of the contract
 address private _creator;
 // the current owner and minter of the contract
 address private _owner;
 // the uri of the off chain metadata of the contract
 string private _metadata_uri;
 // the base uri of the off chain metadata for each token
 string private _base_token_uri;

 Instance[] public instances;

 constructor (string memory metadataUri, string memory baseTokenUri) public {
 _creator = msg.sender;
 _owner = msg.sender;
 _metadata_uri = metadataUri;
 _base_token_uri = baseTokenUri;
 }

 function creator() public view returns (address) {
 return _creator;
 }

 function owner() public view returns (address) {
 return _owner;
 }

 function mint(address account, string memory instanceId) public {
 require(_owner == msg.sender);
 uint256 tokenId = instances.length;
 instances.push(Instance(_owner, account, instanceId));
 _mint(account, tokenId);
 }

 function transferOwnership(address newOwner) public {
 require(_owner == msg.sender);
 _owner = newOwner;
 }

 function burn(uint256 instanceId) public {
 _burn(ownerOf(instanceId), instanceId);
 }

 function contractURI() public view returns (string memory) {
 return _metadata_uri;
 }

 function baseTokenURI() public view returns (string memory) {
 return _base_token_uri;
 }

 function tokenURI(uint256 _tokenId) public view returns (string memory) {
 bytes memory _ba = bytes(_base_token_uri);
 bytes memory _bb = bytes(instances[_tokenId].off_chain_id);
 string memory ab = new string(_ba.length + _bb.length);
 bytes memory bab = bytes(ab);
 uint k = 0;
 for (uint i = 0; i < _ba.length; i++) bab[k++] = _ba[i];
 for (uint i = 0; i < _bb.length; i++) bab[k++] = _bb[i];
 return string(bab);
 }
}

Contract ABI:

[{"constant":true,"inputs":[{"name":"interfaceId","type":"bytes4"}],"name":"supportsInterface","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"creator","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"tokenId","type":"uint256"}],"name":"getApproved","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"tokenId","type":"uint256"}],"name":"approve","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"from","type":"address"},{"name":"to","type":"address"},{"name":"tokenId","type":"uint256"}],"name":"transferFrom","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"owner","type":"address"},{"name":"index","type":"uint256"}],"name":"tokenOfOwnerByIndex","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"from","type":"address"},{"name":"to","type":"address"},{"name":"tokenId","type":"uint256"}],"name":"safeTransferFrom","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"instanceId","type":"uint256"}],"name":"burn","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"index","type":"uint256"}],"name":"tokenByIndex","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"tokenId","type":"uint256"}],"name":"ownerOf","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"to","type":"address"},{"name":"approved","type":"bool"}],"name":"setApprovalForAll","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"instances","outputs":[{"name":"minter","type":"address"},{"name":"original_owner","type":"address"},{"name":"off_chain_id","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"from","type":"address"},{"name":"to","type":"address"},{"name":"tokenId","type":"uint256"},{"name":"_data","type":"bytes"}],"name":"safeTransferFrom","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_tokenId","type":"uint256"}],"name":"tokenURI","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"account","type":"address"},{"name":"instanceId","type":"string"}],"name":"mint","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"baseTokenURI","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"contractURI","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"owner","type":"address"},{"name":"operator","type":"address"}],"name":"isApprovedForAll","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"inputs":[{"name":"metadataUri","type":"string"},{"name":"baseTokenUri","type":"string"}],"payable":false,"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":true,"name":"tokenId","type":"uint256"}],"name":"Transfer","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"approved","type":"address"},{"indexed":true,"name":"tokenId","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"operator","type":"address"},{"indexed":false,"name":"approved","type":"bool"}],"name":"ApprovalForAll","type":"event"}]