React App Setup

This tutorial shows how you can build a basic React app with Create React App that uses the squid-js JavaScript package to publish a data set, get a data set, and more.

Requirements

  • Node.js >= 10 is installed. You can check using node -v
  • npm >= 5.2 is installed. You can check using npm -v
  • Do the tutorial to Set Up Azure Storage.
  • Use a browser with MetaMask and some Ether in your account. See the tutorial about getting Ether and Ocean Tokens for testnets.
  • Git clone the oceanprotocol/barge repository, then in that directory:

    • Edit the brizo.env file and set all AZURE_… values.
    • Run ./start_ocean.sh --no-pleuston --local-kovan-node. This runs several Ocean services locally, including a local Parity Ethereum node connected to the Kovan Testnet.

New Create React App

First, kick start your new React app by creating a boilerplate with Create React App:

npx create-react-app marketplace

This will create a folder named marketplace with a boilerplate React app. Go into that new folder and add the Ocean Protocol JavaScript library and Web3 packages to the app’s dependencies:

cd marketplace/
npm install @oceanprotocol/squid web3

At this point you can already run npm start which starts the app in your browser at localhost:3000:

React App 01

Add Markup & Web3

Let’s make it ours, open src/App.js and replace the whole source with:

import React, { Component } from 'react'
import './App.css'

class App extends Component {
  render() {
    return (
      <div className="App App-header">
        <h1>Marketplace app</h1>
      </div>
    )
  }
}

export default App

Below the import './App.css' line, let’s import the packages we installed, set up web3 and unlock MetaMask accounts (if locked):

import { Ocean } from '@oceanprotocol/squid'
import * as Web3 from 'web3'

const web3 = new Web3(window.web3.currentProvider)
window.ethereum.enable()

After those steps you should see this, and MetaMask should have asked you to allow access to your account:

React App 02 React App 03

Create Ocean instance

Now that we are successfully connected with Web3, we can setup our Ocean instance.

At the beginning of your component, create a new Ocean instance with all configuration within the componentDidMount lifecycle method. All Ocean Protocol operations can be executed from this Ocean instance.

async componentDidMount() {
  this.ocean = await new Ocean.getInstance({
    web3Provider: web3,
    nodeUri: "http://localhost:8545",
    aquariusUri: "http://localhost:5000",
    brizoUri: "http://localhost:8030",
    parityUri: "http://localhost:8545",
    secretStoreUri: "http://localhost:12001",
    threshold: 0,
    password: "secret",
    address: "0x068ed00cf0441e4829d9784fcbe7b9e26d4bd8d0",
  })
  console.log("Finished loading contracts!")
}

Final Result

That’s it, if you have no errors in your console.log then you have successfully initialized an Ocean instance in your brand new React app and you are ready for the next part of this tutorial.

React App 04

Here is the full source of src/App.js that you should have if you followed this tutorial:

import React, { Component } from 'react'
import './App.css'
import { Ocean } from '@oceanprotocol/squid'
import * as Web3 from 'web3'

const web3 = new Web3(window.web3.currentProvider)
window.ethereum.enable()

class App extends Component {
  async componentDidMount() {
    this.ocean = await new Ocean.getInstance({
      web3Provider: web3,
      nodeUri: 'http://localhost:8545',
      aquariusUri: 'http://localhost:5000',
      brizoUri: 'http://localhost:8030',
      parityUri: 'http://localhost:8545',
      secretStoreUri: 'http://localhost:12001',
      threshold: 0,
      password: 'secret',
      address: '0x068ed00cf0441e4829d9784fcbe7b9e26d4bd8d0'
    })
    console.log('Finished loading contracts!')
  }

  render() {
    return (
      <div className="App App-header">
        <h1>Marketplace app</h1>
      </div>
    )
  }
}

export default App

Move on to Publish a Data Set.