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

  • Docker & Docker Compose

  • A Web3 capable browser, like Firefox/Chrome with MetaMask installed

  • Spree, a local Ocean test network

    • Git clone the oceanprotocol/barge repository, then in that directory:
    • (Optional but recommended) Clean out all your old Docker stuff using docker system prune --all --volumes
    • Use the startup script in Barge to run a local Spree Testnet:
    export KEEPER_VERSION=v0.9.1 && \
    export AQUARIUS_VERSION=v0.2.2 && \
    export BRIZO_VERSION=v0.3.5 && \
    ./start_ocean.sh --no-pleuston
    • Note that compiling and deploying the contracts in your local Docker network takes some time so it can take a few minutes until the network is ready to be interacted with. That usually is the case once keeper-contracts_1 container doesn’t show any messages anymore.
  • Some Spree Ether in your MetaMask account. You can execute this, replacing <YOUR ADDRESS> with your MetaMask account address:

    curl --data '{"jsonrpc":"2.0","method":"personal_sendTransaction","params":[{"from":"0x00Bd138aBD70e2F00903268F3Db08f2D25677C9e","to":"<YOUR ADDRESS>","value":"0x7FFFFFFFFFFFFFFFFFF"}, "node0"],"id":0}' -H "Content-Type: application/json" -X POST localhost:8545

New Create React App

First, kickstart 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 to the app’s dependencies:

cd marketplace/
npm install @oceanprotocol/[email protected]

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

React App 01
React App 01

Add Markup & Web3

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

// src/App.js
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):

// src/App.js
import { Ocean } from '@oceanprotocol/squid'
import 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 02
React App 03
React App 03

Note: If you see an error like inpage.js:1 MetaMask - RPC Error: Internal JSON-RPC error. in your console.log, don’t worry about it. It’s a MetaMask thing.

Create Ocean Instance

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

At the beginning of your component (i.e. right after the class App extends Component { line), create a new Ocean instance with all configuration within the componentDidMount lifecycle method. All Ocean Protocol operations can be executed from this Ocean instance.

// src/App.js
//...
async componentDidMount() {
  this.ocean = await new Ocean.getInstance({
    web3Provider: web3,
    nodeUri: 'http://localhost:8545',
    aquariusUri: 'http://localhost:5000',
    brizoUri: 'http://localhost:8030',
    brizoAddress: '0x00bd138abd70e2f00903268f3db08f2d25677c9e',
    parityUri: 'http://localhost:8545',
    secretStoreUri: 'http://localhost:12001'
  })
  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
React App 04

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

// src/App.js
import React, { Component } from 'react'
import './App.css'
import { Ocean } from '@oceanprotocol/squid'
import 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',
      brizoAddress: '0x00bd138abd70e2f00903268f3db08f2d25677c9e',
      parityUri: 'http://localhost:8545',
      secretStoreUri: 'http://localhost:12001'
    })
    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.