Ethereum : Dapp Development Bootcamp

- start project

  - truffle doc --> https://truffleframework.com/docs

  - create a empty folder --> mkdir C:\election

  - truffle prepare for us some template to speed up development process

  - we will use pet-shop template --> truffle unbox pet-shop

  - explain about what petshop have

  - src : contain webui code html,css,js

  - contracts and migrations folder

  - test folder

  - truffle.js file contain blockchain information for deploy smart contract

  - if you on windows --> create truffle-config.js then copy

    all content from truffle.js, then delete truffle.js file

  - if you on mac --> just use truffle.js file

  - this file describe how we will connect to blockchain

  - start ganache

  - create new contract name Election.sol

  with very simple content

  contract Election {

  string public candidate;

  constructor() public {

    candidate = "candidate 1";

  }

}

  - create a new migration file call 2_deploy_election.js

  - deploy start contract to local blockchain -->  truffle migrate

  - try to interact with smart contract

      --> truffle console

      --> Election.deployed().then(function(i){instance=i})

      --> instance.candidate()

- design contract component

    - data for contract

      - need a struct to model a candidate

      - need to manage multiple candidates

      - need to manage multiple voters and state of vote

    - function for contract

      - add candidate function

      - constructor function

      - vote function

    - event for communicate between contract and webui

interact with smart contract from truffle console

- get contract instance -->      Election.deployed().then(function(i){instance=i})

- show contract address -->      instance.address

- get candidate count -->        instance.candidatesCount().then(function(count){vcount=count})

- get candidate name -->        instance.candidates(1).then(function(candidate){name=candidate[1]})

- do vote using account 0 -->      instance.vote(1, {from:web3.eth.accounts[0]})

- get voter state -->       instance.voters(web3.eth.accounts[0])   

- get vote count --> instance.candidates(1).then(function(candidate){voteCount=candidate[2]})

- vote with other voter -->      instance.vote(1, {from:web3.eth.accounts[2]})

- event -->                      instance.vote(1, {from:web3.eth.accounts[8]}).then(function(result){console.log(result.logs[0].args._candidateId)})

/**

  * automation test structure

  * - check init number of candidate

  *

  * - check init value for each candidate

  *

  * - check vote function

  *   - check require candidate id condition for vote function

  *   - check require voter not yet vote condition

  *   - check voters change after vote

  *   - check vote count after vote

  *   - check event happen

  */

- download geth clien from --> https://geth.ethereum.org/downloads/

- install geth and binary will go to --> C:\Program Files\Geth

- start node and syncing use rinkeby network ---> geth --rinkeby 

- attach to console javascript ---> geth attach ipc:\\.\pipe\geth.ipc

- check syncing status (need to wait until all sync complete) --> eth.syncing (should return false)

- create new account --> personal.newAccount()

- list account --> eth.accounts

- get some free eth from faucet --> https://faucet.rinkeby.io/

- check account balance with console --> eth.getBalance(your account address)

- check account balance and convert to ether --> web3.fromWei(your account address,"ether")

- start geth again with command --> geth --rinkeby --rpc --rpcapi db,eth,net,web3,personal

- add define for rinkeby network config to truffle-config.js (use truffle.js on MAC)

  rinkeby: {

      host: "127.0.0.1",

      port: 8545,

      network_id: 4,

      from: "your account address"

    }

  - unlock account before deploy to test network --> personal.unlockAccount(your account address)

  - deploy to rinkeby network after unlock accont ----> truffle migrate --reset --network rinkeby

- switch to rinkeby network on metamask

- improt rinkeby account to metamask ----> C:\Users\TAN\AppData\Roaming\Ethereum\rinkeby\keystore

- scan information after deploy and do vote ----> https://rinkeby.etherscan.io

- register user on infura --> https://infura.io

- go to dashboard and copy the api url with key and use in App.js

- change app.js to use infura host

- truffle hdwallet link --> https://github.com/trufflesuite/truffle-hdwallet-provider

- install windows build tool --> npm install --production windows-build-tools

- install hdwallet --> npm install truffle-hdwallet-provider

- get 12 words for mnenomic from ---> https://iancoleman.io/bip39/

- create test_hdwallet.js to show up address from mnenomic

  - modify app.js to use truffle hdwallet provider   

    ropsten: {

      provider: () => new HDWalletProvider(mnenomic, "https://ropsten.infura.io/v3/abbe691d210c470bbb9e2956e2f82c49"),

      network_id: 3,

      gas: 3000000,

      gasPrice: 21

    },

    get some free ether from ropsten faucet -->https://faucet.ropsten.be/

- deploy to ropsten network --> truffle migrate --reset --network ropsten

- modify app.js to use ropsten infura url api

- use metamask to restore account from seed phrase

- install ipfs --> https://dist.ipfs.io/#go-ipfs

- init a ipfs node --> ipfs init

- run as long service --> ipfs daemon

- check the peer --> ipfs swarm peers

- add all dist folder --> ipfs add -r dist/ 

- publish the hash--> ipfs name publish "hash of dist"

- access dapp from internet --> gateway.ipfs.io/ipfs/"hash of dist"