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

  • Git clone the oceanprotocol/barge repository, then in that directory:

    • (Optional) If you want to use Azure Storage or Amazon S3 storage, then go through the tutorials to set those up: Azure or Amazon. Note that if you’re using Azure Storage, you must edit the barge/brizo.env file and set all AZURE_… values.
    • Use Barge to run a local Spree Testnet:
    export KEEPER_VERSION=v0.8.6
    ./start_ocean.sh --latest --no-pleuston --local-spree-node
  • Get some Spree Ether in a local account managed by MetaMask.

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 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

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, 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: "node0",
    address: "0x00bd138abd70e2f00903268f3db08f2d25677c9e",
  })
  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: 'node0',
      address: '0x00bd138abd70e2f00903268f3db08f2d25677c9e'
    })
    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.