Accessing a 3rd party contract's functions using Truffle

Question

I'm trying to build a basic dashboard that will allow me to track the status of any given ICO (assuming the token is ERC20).

Right now, I managed to deploy a simple Crowdsale + Coin contract based on OpenZeppelin and Truffle and I am able to access the state variables and functions on an Angular 2 frontend I built.

The next thing I did, which is also working fine, is using web3 (without Truffle) to access another deployed Token, for example BAT and read its public state variables. This was achieved with this code:

  var abi = [...] ;
  // Copied ABI from Etherscan https://etherscan.io/address/0x0d8775f648430679a709e98d2b0cb6250d2887ef#code 

  var MyContract = this.web3.eth.contract(abi);

  // initiate contract for an address
  var myContractInstance = MyContract.at('0x0D8775F648430679A709E98d2b0Cb6250d2887EF'); //Address to which BAT token is deployed.

  // call constant function (synchronous way)
  //var owner = myContractInstance .owner.call();

  console.log(myContractInstance);

  myContractInstance.totalSupply.call({from: this.account},
    function(error, result){
      console.log(result.toString(10))
  });

This effectively allowed me to access totalSupply of BAT from my own frontend.

Now, I'm having a hard time figuring out how I could replicate this code, but using Truffle instead of web3 calls.

I'm currently accessing my own deployed contracts like this:

//Contracts have been built with Truffle here:
const crowdsaleArtifacts = require('../../build/contracts/PabloCoinCrowdsale.json');
const coinArtifacts = require('../../build/contracts/PabloCoin.json');

Crowdsale = contract(crowdsaleArtifacts);
Coin = contract(coinArtifacts);

//Bootstrap abstraction for use.
this.Crowdsale.setProvider(this.web3.currentProvider);
this.Coin.setProvider(this.web3.currentProvider);

//Once everything is loaded, for example, get totalSupply of Coin
this.getCoinInstance();

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 totalSupply.
          this.coinInstance = instance2;
          this.totalSupply();
        })
      })
    })
    .catch(e => {
      console.log("ERR",e);
    });
  }

totalSupply(){
    this.coinInstance.totalSupply({
      from: this.account
    })
    .then(value =>{
      console.log("Total Supply:",this.web3.fromWei(value, "ether").toString(10));
    })
    .catch(e => {
      console.log(e);
    });
  }

Answer 1

Figured it out. Here's the code:

      var MyTruffleContract = contract({
        abi: abi //ABI obtained from Etherscan.
      })

      MyTruffleContract.setProvider(this.web3.currentProvider);
      console.log(MyTruffleContract);

      MyTruffleContract
      .at("0x0D8775F648430679A709E98d2b0Cb6250d2887EF") //Address of the contract, obtained from Etherscan
      .then(instance =>{
        instance.totalSupply({
          from: this.account
        })
        .then(value =>{
          console.log("Total Supply:",this.web3.fromWei(value, "ether").toString(10));
        })
        .catch(e => {
          console.log(e);
        });
      })