zeppelin-solidity Crowdsale. Access to token using javascript

Question

I'm trying to use javascript to access the token variables and functions provided in the MintToken.sol file in openzeppelin.

I used "truffle init webpack" to create the metacoin example provided by truffle. I use "truffle compile", "truffle migrate" and "npm run dev" to have an application running in javascript that, using web3, let me interact with the smart contract.

I would like to do the same with zeppelin-solidity. So I created my crowdsale smart contract :

pragma solidity ^0.4.11;

import '../node_modules/zeppelin-solidity/contracts/crowdsale/Crowdsale.sol';

contract MyCrowdsale is Crowdsale {
    function MyCrowdsale(uint256 _startTime, uint256 _endTime, uint256 _rate, address _wallet)
        Crowdsale(_startTime, _endTime, _rate, _wallet)
    {
    }  
}

Crowdsale.sol has some fields and a mintable token:

contract Crowdsale {
  using SafeMath for uint256;

   MintableToken public token;

  // start and end timestamps where investments are allowed (both inclusive)
  uint256 public startTime;
  uint256 public endTime;
....

MintableToken.sol inherits from StandardToken (that has balanceOf method) and has some variables:

contract MintableToken is StandardToken, Ownable {
  event Mint(address indexed to, uint256 amount);
  event MintFinished();

  bool public mintingFinished = false;
....

The problem I have is that I'm able to access to the crowdsale variables like startTime and endTime, but I'm not able to access to token variables/methods like balanceOf, mintingFinished, etc.

In my app.js I tried to copy the code used to access the metacoin contract so I'm able to get the startDate, for example:

MyCrowdsale.deployed().then(function(instance) {
    return instance.startTime.call();
  }).then(function(value) {
    var startDate = value.valueOf();
    console.log("The startDate is " + startDate);
  }).catch(function(e) {
    console.log(e);
    self.setStatus("Error getting startDate; see log.");
  });

I can get the token address using this call:

MyCrowdsale.deployed().then(function(instance) {
    return instance.token.call();
  }).then(function(mintedToken) {
    console.log("The mintedToken is " + mintedToken.valueOf());
  }).catch(function(e) {
    console.log(e);
  });

But I'm stuck here. I would like to access to token.balanceOf() or token.mintingFinished but I don't know how to do it.

I tried (after getting the token address like I wrote before):

console.log("mintingFinished = " + mintedToken.mintingFinished);

and also:

mintedToken.mintingFinished.call().then(function(x) {
      console.log("mintingFinished = " + x);
    })

But none of these approaches worked.

Any help would be appreciated.

Answer 1

I hope I got your question right. The Syntax for public vars and mappings is:

YourContract.deployed().then(function(instance) {
    return instance.publicVar.call();
  }).then(function(result) {
    console.log(result.toString());
  }).catch(function(e) {
    console.log(e);
  });

and mappings:

YourContract.deployed().then(function(instance) {
    return instance.publicMapping.call(mappingKey);
  }).then(function(result) {
    console.log(result.toString());
  }).catch(function(e) {
    console.log(e);
  });

where mappingKey stands for the solidity equivalent of

mapping (datatype1 => datatype2) public publicMapping;

publicMapping[mappingKey];

of course don't forget to make sure mappingKey is equivalent to the datatype1 .

Answer 2

Try with this code:

getCoinInstance(){
    this.Crowdsale
    .deployed()
    .then(instance =>{
      //Set the ref for the contract and look up it's associated token
      this.crowdsaleInstance = instance;
      this.crowdsaleInstance.token()
      .then(addr => {
        this.Coin.at(addr)
        .then(instance2 =>{
          // set the ref for the token and get user's balance.
          console.log(this.account);
          this.coinInstance = instance2;
          //NOW you got a hold of the token instance, call any function you want with it.
          this.balanceOf(this.account);
        })
      })
    })
    .catch(e => {
      console.log("ERR",e);
    });
  }

balanceOf(address:string){
    this.coinInstance.balanceOf(address,{
      from: this.account
    })
    .then(value =>{
      console.log("balance",this.web3.fromWei(value, "ether").toString(10));
    })
    .catch(e => {
      console.log(e);
    });
  }