Ethereum Shop

This tutorial is meant for those with a basic knowledge of Ethereum and smart contracts, who have some knowledge of HTML and JavaScript, but who are new to dapps.

What we'll do

• Setting up the development environment.
• Creating a Truffle project using a Truffle Box.
• Writing the smart contract.
• Migrating the smart contract.
• Creating a user interface to interact with the smart contract.
• Interacting with the dapp in a browser.

Default config for truffle.js

module.exports = {
    networks: {
        development: {
            host: "127.0.0.1",
            port: 8545,
            network_id: "*" // Match any network id
        }
    }
};

Window's user rename the truffle.js file to truffle-config.js

How to setup

Install NodeJS (includes NPM 5.5.1) https://nodejs.org/en/download/

Open terminal and run

1. Install Truffle globally npm install -g truffle

2. Clone the project using git clone https://github.com/sany2k8/ethshop.git

3. Install the dependencies from package.json file npm install

4. Now, you have 3 choices whether you can use Truffle develop , TestRpc or Geth

   A. Using Truffle develop

   • Run the development console. truffle develop

   • Compile the smart contracts. compile

   • Migrate the smart contacts. migrate

   B. Using TestRpc (That has built-in HD Wallet)

   • Install testrpc, using npm install -g ethereumjs-testrpc https://github.com/ethereumjs/testrpc

   • Run the testrpc using testrpc

   • Migrate the smart contacts truffle migrate

   C. Using Geth

   • Install geth on ubuntu by following commands

     sudo apt-get install software-properties-common

     sudo add-apt-repository -y ppa:ethereum/ethereum

     sudo apt-get update

     sudo apt-get install geth

   More info: https://github.com/ethereum/go-ethereum/wiki/Installation-Instructions-for-Ubuntu

   • Install geth on windows by following step

     All versions of Geth are built and available for download at https://geth.ethereum.org/downloads/

     The download page provides an installer as well as a zip file. The installer puts geth into your PATH automatically. The zip file contains the command .exe files and can be used without installing.

     • Download zip file

     • Extract geth.exe from zip

     • Open a command prompt

     • chdir

     • open geth.exe

   More info: https://github.com/ethereum/go-ethereum/wiki/Installation-instructions-for-Windows

   • Migrate the smart contacts truffle migrate

Geth:

• Create a directory anywhere on your system using e.g mkdir geth

• Change directory cd geth

• Make data directory mkdir datadir

• Create genesis.json file using touch genesis.jsonwith the below example configuration

   {
       "config": {
           "chainId": 42,
           "homesteadBlock": 0,
           "eip155Block": 0,
           "eip158Block": 0
       },
       "nonce": "0x000000000000002a",
       "difficulty": "0x04000",
       "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
       "coinbase": "0x0000000000000000000000000000000000000000",
       "timestamp": "0x00",
       "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
       "extreaData": "0x",
       "gasLimit": "0x47E7C4",
       "alloc": {
                 "f44cf64f2cb6381e260355d6d44c2b09a82c488b": {
                 "balance": "31337000000000000000000000000"
                },
                 "e2331f931fd65388d6bff717b9aacccf0e400b45": {
                 "balance": "31338000000000000000000000000"
                },
                 "d0612efd9c7410fb73d5ce3d530a896c5428e31a": {
                 "balance": "31339000000000000000000000000"
                },
                 "4d60895f05d587df75dcacc74ff598bb93d23830": {
                 "balance": "31336000000000000000000000000"
                },
                 "7e7034bb21709dd9dba6a19c7549adcb95af8a34": {
                 "balance": "31335000000000000000000000000"
                }
          }
    }

Initialize Geth:

geth --datadir=./datadir init genesis.json

Start Geth RPC:

geth --port 3500 --networkid 42 --nodiscover --datadir="datadir" --rpc --rpcport 8545 --rpcaddr 0.0.0.0 --rpccorsdomain "*" --rpcapi "eth,net,personal,web3"

Attach to geth cosole:

geth attach ipc:\\.\pipe\geth.ipc Change it as per your ipc path, here I just used mine

Example Commands:

personal.newAccount("123456789")

personal.newAccount("987654321")

personal.listAccounts

miner.start(1)

eth.mining

personal.unlockAccount(eth.accounts[0], "123456789", 86400)

eth.getBalance(eth.accounts[0]);

5. Run the liteserver development server (outside the development console) for front-end hot reloading.

   • Run the DAPP : npm run dev

The DAPP will serve the front-end on http://localhost:3000

MetaMask

MetaMask is a bridge that allows you to visit the distributed web of tomorrow in your browser today. It allows you to run Ethereum dApps right in your browse. The fastest way to connect is through Chrome and MetaMask as described below.

https://www.dcorp.it/chrome_and_metamask

https://www.cryptocompare.com/wallets/guides/how-to-use-metamask/