I try to learn solidity and i have a problem. I've created a base token and i want to call the balanceof method from this token in another contract. In Solidity Remix i get :
call to BaseTokenBet.getTokenBalance errored: VM error: revert.
revert The transaction has been reverted to the initial state.
Note: The constructor should be payable if you send value. Debug the transaction to get more information.
My BaseToken :
pragma solidity >=0.4.22 <0.6.0;
interface tokenRecipient {
function receiveApproval(address _from, uint256 _value, address _token,
bytes calldata _extraData) external;
}
contract BaseToken {
// Public variables of the token
string public name;
string public symbol;
uint8 public decimals = 18;
// 18 decimals is the strongly suggested default, avoid changing it
uint256 public totalSupply;
// This creates an array with all balances
mapping (address => uint256) public balanceOf;
mapping (address => mapping (address => uint256)) public allowance;
// This generates a public event on the blockchain that will notify
clients
event Transfer(address indexed from, address indexed to, uint256
value);
// This generates a public event on the blockchain that will notify
clients
event Approval(address indexed _owner, address indexed _spender,
uint256 _value);
// This notifies clients about the amount burnt
event Burn(address indexed from, uint256 value);
/**
* Constructor function
*
* Initializes contract with initial supply tokens to the creator of
the contract
*/
constructor() public {
totalSupply = 10000 * 10 ** uint256(decimals); // Update total
supply with the decimal amount
balanceOf[msg.sender] = totalSupply; // Give the
creator all initial tokens
name = "BaseToken"; // Set the
name for display purposes
symbol = "BASETOKEN"; // Set the
symbol for display purposes
}
function getBalance() public pure returns (string memory){
return "some string";
}
/**
* Internal transfer, only can be called by this contract
*/
function _transfer(address _from, address _to, uint _value) internal {
// Prevent transfer to 0x0 address. Use burn() instead
require(_to != address(0x0));
// Check if the sender has enough
require(balanceOf[_from] >= _value);
// Check for overflows
require(balanceOf[_to] + _value >= balanceOf[_to]);
// Save this for an assertion in the future
uint previousBalances = balanceOf[_from] + balanceOf[_to];
// Subtract from the sender
balanceOf[_from] -= _value;
// Add the same to the recipient
balanceOf[_to] += _value;
emit Transfer(_from, _to, _value);
// Asserts are used to use static analysis to find bugs in your
code. They should never fail
assert(balanceOf[_from] + balanceOf[_to] == previousBalances);
}
/**
* Transfer tokens
*
* Send `_value` tokens to `_to` from your account
*
* @param _to The address of the recipient
* @param _value the amount to send
*/
function transfer(address _to, uint256 _value) public returns (bool
success) {
_transfer(msg.sender, _to, _value);
return true;
}
/**
* Transfer tokens from other address
*
* Send `_value` tokens to `_to` on behalf of `_from`
*
* @param _from The address of the sender
* @param _to The address of the recipient
* @param _value the amount to send
*/
function transferFrom(address _from, address _to, uint256 _value)
public returns (bool success) {
require(_value <= allowance[_from][msg.sender]); // Check
allowance
allowance[_from][msg.sender] -= _value;
_transfer(_from, _to, _value);
return true;
}
/**
* Set allowance for other address
*
* Allows `_spender` to spend no more than `_value` tokens on your
behalf
*
* @param _spender The address authorized to spend
* @param _value the max amount they can spend
*/
function approve(address _spender, uint256 _value) public
returns (bool success) {
allowance[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
/**
* Set allowance for other address and notify
*
* Allows `_spender` to spend no more than `_value` tokens on your
behalf, and then ping the contract about it
*
* @param _spender The address authorized to spend
* @param _value the max amount they can spend
* @param _extraData some extra information to send to the approved
contract
*/
function approveAndCall(address _spender, uint256 _value, bytes memory
_extraData)
public
returns (bool success) {
tokenRecipient spender = tokenRecipient(_spender);
if (approve(_spender, _value)) {
spender.receiveApproval(msg.sender, _value, address(this),
_extraData);
return true;
}
}
/**
* Destroy tokens
*
* Remove `_value` tokens from the system irreversibly
*
* @param _value the amount of money to burn
*/
function burn(uint256 _value) public returns (bool success) {
require(balanceOf[msg.sender] >= _value); // Check if the sender
has enough
balanceOf[msg.sender] -= _value; // Subtract from the
sender
totalSupply -= _value; // Updates totalSupply
emit Burn(msg.sender, _value);
return true;
}
/**
* Destroy tokens from other account
*
* Remove `_value` tokens from the system irreversibly on behalf of
`_from`.
*
* @param _from the address of the sender
* @param _value the amount of money to burn
*/
function burnFrom(address _from, uint256 _value) public returns (bool
success) {
require(balanceOf[_from] >= _value); // Check if the
targeted balance is enough
require(_value <= allowance[_from][msg.sender]); // Check
allowance
balanceOf[_from] -= _value; // Subtract
from the targeted balance
allowance[_from][msg.sender] -= _value; // Subtract
from the sender's allowance
totalSupply -= _value; // Update
totalSupply
emit Burn(_from, _value);
return true;
}
}
In my second contract i try to call balanceOf:
pragma solidity >=0.4.22 <0.6.0;
import "./BaseToken.sol";
contract BaseTokenBet {
BaseToken public baseToken;
address public owner;
constructor() public {
owner = msg.sender;
baseToken = BaseToken(owner);
}
function getOwner() public view returns (address) {
return owner ;
}
function getBaseToken() public view returns (BaseToken) {
return baseToken ;
}
function getTokenBalance() public view returns (uint256){
return baseToken.balanceOf(owner);
}
}
When i call getTokenBalance i get the error posted above.
Can someone put on the right track with this?
