Using Web3 1.x with React Native

A boilertemplate for using Web3 1.x with React Native

Test Environment

node: v10.4.1
yarn: 1.12.3
react: 16.6.3
react-native: 0.57.8
web3: 1.0.0-beta.37

Operating System
iOS Simuator: iPhone X iOS 12.1
Android Simulator: AVD Nexus 5X API 27

Setup

1. git clone [email protected]:anakornk/web3WithReactNative.git
2. yarn install
3. ganache-cli
4. react-native run-ios or react-native run-android

Step By Step Guide

1. Create a new React Native Project

react-native init web3WithReactNative

2. Install Node core modules for React Native

yarn add node-libs-react-native
yarn add vm-browserify

3. In the project root directory, create rn-cli.config.js

const nodeLibs = require('node-libs-react-native');
nodeLibs.vm  = require.resolve('vm-browserify');

module.exports = {
  resolver: {
    extraNodeModules: nodeLibs
  },
};

4. In the project root directory, create globals.js

import url from "url";
global.URL = class URL {
  constructor(inputUrl) {
    return url.parse(inputUrl);
  }
};

if (typeof btoa === 'undefined') {
  global.btoa = function (str) {
    return new Buffer(str, 'binary').toString('base64');
  };
}

if (typeof atob === 'undefined') {
  global.atob = function (b64Encoded) {
    return new Buffer(b64Encoded, 'base64').toString('binary');
  };
}

5. At the top of index.js, import these modules

import 'node-libs-react-native/globals';
import './globals.js';

6. Install and Link react-native-randombytes

yarn add react-native-randombytes
react-native link

7. Install web3

yarn add web3

8. Import and Test web3

In App.js, import web3.

import Web3 from 'web3';

Add the following code inside your App React component. The code will print out information of the latest block and accounts

  componentWillMount() {
    this.web3  = new Web3('ws://localhost:8545');
    this.web3.eth.getBlock('latest').then(console.log).catch(console.log);
    this.web3.eth.getAccounts(function(error,res) {
      if(!error) {
        console.log(res);
      } else {
        console.log(error);
      }
    });
  }

9. Run

ganache-cli
react-native run-ios

References

1. https://gist.github.com/dougbacelar/29e60920d8fa1982535247563eb63766
2. parshap/node-libs-react-native#6
3. facebook/react-native#16434

Extra

1. The above code uses websocket provider, if you want to use http provider, you will need to edit a node_modules file since there's currently a problem with XMLHttpRequest. For more information, please see the link below:
   souldreamer/xhr2-cookies#7
2. vm-browserify is not a RN-compatible polyfill for vm, but works for now. For more information, please see the link below: parshap/node-libs-react-native#6