React Native

The React Native environment has a lot of little quirks, so this documentation is aimed at helping smooth those over.

Please feel free to create issues on GitHub for recommendations and additions to this document.


Shims

There are several pieces of functionality missing from the current version of React-Native. Here is a list of functionality the ethers/dist/shims will provide if unavailable:

  • ArrayBuffer.isView

  • atob and btoa

  • nextTick

  • Promise

  • String.prototype.normalize

Importing into React-Native
// Import the required shims
import 'ethers/dist/shims.js';

// Import the ethers library
import { ethers } from 'ethers';
Note

This file must be minified, since the React-Native require seems to hijack the variable name require, even when encapsulated inside a closure. The minification process replaces the require with a mangled name, so that there is no collision. This is hacky and in the future a better method would be preferred. Suggestions?

Note

As we find additional features not generally available, they will be added to this shim file. It is targetted toward platforms where build-size is not critical, so functionality is favored over keeping the size small.


Wordlists

React-Native will pull in the browser version of ethers, which does not have all the additional word lists, by default. Each desired wordlist must be separately imported.

Importing languages into React-Native
import {
    es,     // Spanish
    fr,     // French
    it,     // Italian
    ja,     // Japanese
    ko,     // Korean
    zh_ch,  // Chinese (simplified)
    zh_tw   // Chinese (tranditional)
} from 'ethers/wordlists';

Other Notes

console.log

The use of console.log in React Native can substantially impact performance. For this reason, you may wish to reduce the log level to not show info and warnings.

Change Log Level
// The default is "info"; other options
// "debug", "info", "warn", "error", "off"
ethers.errors.setLogLevel("error");

TODO: Include instructions on installing crypto performance

  • scrypt (it is VERY slow in React Native; too slow to be functional)