Crowdsale Contract – How to Mint Tokens in Another Token Contract

erc-20icoopenzeppelintokens

I'm trying to create a crowdsale contract with open-zeppelin. I'm using SampleCrowdsale.sol. I believe the following line of code creates a token contract and mints the token upon receiving ether.

function createTokenContract() internal returns (MintableToken) {
    return new SampleCrowdsaleToken();
  }

However, I rather want the crowdsale contract to mint a token in another mintable token contract. Is there any way the crowdsale contract can interact with an external token contract? Any suggestion or code snippet would be really helpful.

Best Answer

Yes what you need to do is first create your token in a separate contract. Then when you create your crowdsale you pass in the constructor the address of your token.

This is a sample taken from the Ethereum Crowdfund your idea

pragma solidity ^0.4.16;

interface token {
    function mintToken(address receiver, uint amount);
}

contract Crowdsale {
    token public tokenReward;

    /**
     * Constrctor function
     */
    function Crowdsale(
        address addressOfTokenUsedAsReward
    ) {
        tokenReward = token(addressOfTokenUsedAsReward);
    }
}

Related Solutions

[Ethereum] Interacting with a deployed contract: How to mint a token based on the Open Zeppelin Standard

Have a look at Interacting with smart contracts using truffles.

If you deployed your smart contract with the name SampleCrowdsale, for example with

var mycrowdsale = SampleCrowdsale.deployed();

then you have access to the function mint():

mycrowdsale.mint(to, amount);

with to as the receiver address and amount the number of tokens created.

You can also check it works with:

mycrowdsale.mint(to, amount).then(function(balanceOf(to)) {
  // If this callback is called, the call was successfully executed.
  // Note that this returns immediately without any waiting.
  // Let's print the return value.
  console.log(balance.toNumber());
}).catch(function(e) {
  // There was an error! Handle it.
})

balanceOf is a standard ERC20 function.

You can look at this Interacting with your contracts tutorial where I took the example.

OpenZeppelin Pausable Contract – Pausable Contract in OpenZeppelin

The Pausable contract you're inheriting from just adds pause and unpause, which updates a state variable paused. But that's all it does by itself.

You'll need to use the modifiers whenPaused and whenNotPaused in your contract. If you put whenNotPaused on a function, then that function won't be callable when the contract is in the paused state. (For example, you might want to put that on whatever function is selling people coins during your ICO.)

Best Answer

Related Solutions

[Ethereum] Interacting with a deployed contract: How to mint a token based on the Open Zeppelin Standard

OpenZeppelin Pausable Contract – Pausable Contract in OpenZeppelin

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