Meetup Blockchain e Chatbot 11/11/2017 - node.js

gistfile1.txt

var express = require('express');
var app     = express();
var server  = require('http').createServer(app);

var bodyParser = require('body-parser')
app.use( bodyParser.json() );
app.use(bodyParser.urlencoded({
  extended: true
}));

var http = require('http')
var port = 3000
var Web3 = require('web3');

var web3 = null;
var urlNode = 'http://localhost:8545/';
web3 = new Web3(new Web3.providers.HttpProvider(urlNode));

function checkWeb3(){
    if (web3 && web3.isConnected()) {
        console.info('Connected');
    } else {
        console.info('Not Connected');
    }
}

app.post('/enviarEther', function (req, res) {
    sendEther(
        req.body.accountUnlock,
        req.body.password,
        req.body.accountUnlock,
        req.body.receiver,
        req.body.amount
    );    
    var json = JSON.stringify({ 
        messages: [{
            "text": "ok",
            },
            {
                "text": "transação efetuada",
            }
        ]
      });
      res.end(json);
});

function sendEther(accountUnlock, password, sender, receiver, amount) {
    
    web3.personal.unlockAccount(accountUnlock, password, function(error, result)  {
        if(error){
            console.info(error);
        } else {
            if(result){
                console.info('Account unlock');
                web3.eth.sendTransaction({
                    "from": sender,
                    "to": receiver,
                    "value": web3.toWei(amount, 'ether'),
                    "gas": 300000},
                    function(error, result)  {
                    if(error){
                        console.info(error);
                    } else {
                        if(result){
                            console.info("transaction send" + result);
                        } else {
                            console.info("It wasn't possible to send transaction.");
                        }   
                    }
                });                 
            } else {
                console.info("It wasn't possible to unlock the account.");
            }   
        }
    });   
}
  
server.listen(port, (err) => {
    if (err) {
      return console.log('something bad happened', err)
    }
    console.log(`server is listening on ${port}`)
})

gistfile2.txt

Exercicios


1- Donwload Geth
https://geth.ethereum.org/downloads/

2- Variaveis de ambiente
- Mac vi ~/.bash_profile 
#GETH ETHEREUM
export GETH_HOME=/Users/hgleite/Documents/ferramentas/geth 
export PATH=$PATH:$GETH_HOME

para salvar ESC :wq

Feche o bash_profile e salve

Execute
source ~/.bash_profile 

- Windows adicionar geth no PATH

3- Subir com console para criar uma conta
geth --dev console

personal.newAccount("12345678")

Criem mais duas contas para as ongs

//verificar saldo da conta
eth.getBalance("sua conta")

4- Subir o geth para minerar
geth --dev --mine

5- Acessar o console do nó
Abrir outro terminal e executar geth attach ipc:\\.\pipe\geth.ipc

6- listar contas
Acessar o console
personal.listAccounts(
*Libs(Debug; eth ; personal ; web3 ;)

7- Exercicio
- Enviar ether de uma conta para outraa


> personal.unlockAccount("0xeb519618e013a95e0e87f3d3ef0ec8a048a333d1", "12345678" )
true
> eth.sendTransaction({from:eth.accounts[0], to:eth.accounts[1], value: web3.toWei(0.1, "ether")})
"0x990d9fca0024d0bbc231c256fdce76aa7a049bf37c75bdcc109204941255f72d"
> eth.getBalance(eth.accounts[1])
100000000000000000
> eth.getBalance(eth.accounts[0])
4.8119e+21
>

8- Baixar ethereum wallet
https://github.com/ethereum/mist/releases

Instalar

9- Ir até o endereço do executável e executar via comando
-- EthereumWallet.exe --rpc http://localhost:8545

10- liberar rpc
geth --dev --rpc --rpcaddr "localhost" --rpcport "8545" --rpcapi "web3,eth,net,personal"  --mine
geth --DIR --rpc --rpcaddr "localhost" --rpcport "8545" --rpcapi "web3,eth,net,personal"  --mine

11- Estudar o projeto de crowd funding do site da Ethereum

12- Acessar remix para testar o contrato
https://remix.ethereum.org/

13- Compilar e realizar o contrato no mist



post
accountUnlock, password, sender, receiver, amount

https://ethereum.stackexchange.com/questions/20874/payable-function-in-solidity


        function deposit() payable {
            amountRaised += msg.value;
    }