Feature Flag

Installation

yarn add ...

Usage

Stories & Documentation

Prepare Feature Flag Config

const config = [{
    name: 'Light Mode',
    id: 'lightMode',
    defaultValue: false,
  }, {
    name: 'Show icon',
    id: 'showIcon',
    options: [{
      name: 'Right',
      value: 'flex-start',
    }, {
      name: 'Center',
      value: 'center',
    }, {
      name: 'Left',
      value: 'flex-end',
    }],
    defaultValue: 'flex-start'
  }
]

Config Item

property	type	required	description
name	string	Yes	Flag's name. It will be written on Flag Panel
id	string	Yes	Unique property for flag
defaultValue	string	No	You can use it when you need default value for flag
options	array	No	Array of object, which holds options' names and values

Feature Flag Provider

Wrap your root component with FeatureFlagProvider and pass your config to it with the config prop.

import { FeatureFlagProvider } from './FeatureFlag';

ReactDOM.render(
  <FeatureFlagProvider config={featureConfig}>
    <App />
  </FeatureFlagProvider>,
  document.getElementById('root')
);

FeatureFlagProvider Props

property	type	required	description
config	object	No	Array of config item
isPanelVisible	bool	No	Set false to hide feature panel

How to get flag value from inside of the React Component

Use useFeatureFlag hook for reaching flag value from React Component. You can pass it string(flag id) or array of string(flag id).

import { useFeatureFlag } from './FeatureFlag';

function App() {
  const showIcon = useFeatureFlag('showIcon');
  const [lightMode] = useFeatureFlag(['lightMode']);

  return (
    <div className="App">
      <header className={`App-header${lightMode ? ' light' : ''}`}>
        {showIcon && <img src={logo} className="App-logo" alt="logo" style={{ alignSelf: showIcon }} />}
      </header>
    </div>
  );
}

How to get flag value from outside of the React Component

Use getFeatureFlag function for reaching flag value wherever you want. You can pass it string(flag id) or array of string(flag id).

import { getFeatureFlag } from './FeatureFlag';

const calculate = () => {
  return getFeatureFlag('coefficient') * value;
}

Feature Flag Panel

If the flag value is changed from Featuer Flag Panel. Its value will be written to your localstorage. So It wont be reset after refreshing the browser.