using-truffle.md

Create Project Using Truffle

create project

mkdir -p /path/to/GreetingsTruffle/ && cd $_
truffle init

remove example files contracts/ConvertLib.sol contracts/MetaCoin.sol test/*

create file contracts/Greetings.sol

pragma solidity ^0.4.11;

contract Greetings {
  string message;

  function Greetings() public {
    message = "I am ready!";
  }

  function setGreetings(string _message) public {
    message = _message;
  }

  function getGreetings() public returns (string) {
    return message;
  }
}

edit file migrations/2_deploy_contracts.js

var Greetings = artifacts.require("./Greetings.sol");

module.exports = function(deployer) {
  deployer.deploy(Greetings);
};

start testrpc in another terminal

testrpc

deploy the contract

truffle migrate  # deploy the contract to the test rpc node
truffle migrate  # this will do nothing because the contract is already deployed
truffle migrate --reset  # this will force deploy the contract again

start a truffle console

truffle console

inside the truffle console

Greetings.address  // show the address of greeting contract
web3.eth.accounts  // list all the accounts
Greetings.deployed().then(function (instance) {app = instance})  // get greeting contract instance
app.getGreetings.call()  // "I am ready!", this do not need gas
web3.eth.getBalance(web3.eth.accounts[1]).toString()  // '100000000000000000000', default balance set by testrpc
app.setGreetings("42", {from : web3.eth.accounts[1]})  // account[1] execute the contract
web3.eth.getBalance(web3.eth.accounts[1]).toString()  // '99996722600000000000'
app.getGreetings.call()  // "42"