flagsmith-react

Flagsmith SDK for React Single Page Applications (SPA).

!CI Action

Contents

Installation

Using npm

``bash
npm install flagsmith-react
`

Using yarn

`bash
yarn add flagsmith-react
`

Getting Started

Configure the SDK by wrapping your application in a FlagsmithProvider element:

`jsx
// src/index.js
import React from 'react';
import ReactDOM from 'react-dom';
import {FlagsmithProvider} from 'flagsmith-react';
import App from './App';

ReactDOM.render(
environmentId="YOUR_FLAGSMITH_ENVIRONMENT_ID"
>

,
document.getElementById('app')
);
`

The Flagsmith Provider defaults to using the vanilla JavaScript Flagsmith SDK. To support alternative SDK, for example the React Native variant, a specific provider can be supplied as a parameter, for example

`jsx
// src/index.js
import React from 'react';
import ReactDOM from 'react-dom';
import {FlagsmithProvider} from 'flagsmith-react';
import flagsmith from 'react-native-flagsmith';
import App from './App';

ReactDOM.render(
environmentId="YOUR_FLAGSMITH_ENVIRONMENT_ID"
flagsmith={ flagsmith }
>

,
document.getElementById('app')
);
`

Use the useFlagsmith hook in your components to access the Flagsmith state (isLoading, isIdentified, isError) and feature flag and remote configuration methods (hasFeature, getValue etc.)


`jsx
import React from 'react';
import { useFlagsmith } from 'flagsmith-react';

function App() {
const {
isLoading,
isError,
hasFeature,
getValue
} = useFlagsmith();

if (isLoading) {
return

export default App;
`

API Reference

> The flagsmith-react API is modelled on the Flagsmith Javascript integration, the documentation for which can be found here for further reference.

$3

`jsx
environmentId
flagsmith
asyncStorage
cacheFlags
defaultFlags
preventFetch
api>

`

Use the FlagsmithProvider component to wrap your application and allow child elements to access the Flagsmith functionality using the 'useFlagsmith' hook function.

$3

`javascript
const {
isLoading,
isIdentified,
isError,
identify,
hasFeature,
getValue,
subscribe
} = useFlagsmith();
`

Use the useFlagsmith hook in your components to access the Flagsmith state and methods.

$3

True if the Flagsmith state is loading, false is the state is loaded and usable. You should not try accessing the state (i.e. feature flags and remote configuration) until this is false and the state is loaded.

$3

True if Flagsmith has been configured to use a specific identity when resolving flags and remote configuration, false otherwise.

See identify for more information.

$3

True if Flagsmith is configured to listen for updates. See startListening for more details.

$3

True if the Flagsmith integration is in an errored state (e.g. the server could not be reached). False otherwise.

$3

`javascript
await identify(identity)
`

Passes the supplied identity to the Flagsmith backend to be used when resolving feature flags and remote configuration. This causes an update in the state, which is an async action. Use the isIdentified flag to determine when the state has been re-loaded, or use subscribe to receive an update notification.

$3

`javascript
await logout()
`

Remove any identity associated with the Flagsmith client. Use the isIdentified flag to determine when the state has been re-loaded, or use subscribe to receive an update notification.

$3

`javascript
hasFeature(key)
`

Determines is the feature specified key is set or not.

$3

`javascript
getValue(key)
`

Gets the current value of the remote configuration item specified by the key.

$3

`javascript
startListening(interval = 1000)
`
Begin listening for backend configuration changes. The polling interval is specified in mS. Use isListening to determine the current listening state, and subscribe to be notified of updates.

$3

`javascript
stopListening()
`
Stop listening (polling) for configuration changes.

$3

`javascript
subscribe(callback)
`

Registers a callback with Flagsmith that will be triggered any time a new configuration is available, for example after loading is complete, or when a new user is identified. This can be used to update any configuration state in components using Flagsmith, per the following example.

`javascript
import { useEffect, useState } from 'react'
import logo from './logo.svg';
import './App.css';
import { useFlagsmith } from 'flagsmith-react'

function App() {
const { isLoading, isError, getValue, identify, subscribe } = useFlagsmith()
const [val, setVal] = useState()

useEffect(() => {
if(!isLoading) {
identify('someone@somewhere.com')
}
}, [isLoading, identify])

const handleChange = () => {
setVal( getValue('val') )
}

subscribe(handleChange)

return (
<>
{
!isLoading &&


Edit src/App.js and save to reload.

className="App-link"
href="https://reactjs.org"
target="_blank"
rel="noopener noreferrer"
>
Learn React

{
isError &&

Flagsmith failed to load

}
{
val &&

{val}

}

export default App;
`

$3

`javascript
await getFlags()
`

Forces a fetch of the current flags.

$3

`javascript
getTrait(key)
`

Can only be used once a user has been identified, to get the value of the specified trait for that user.

$3

`javascript
await setTrait(key, value)
`

Can only be used once a user has been identified, to set the value of the specified trait for that user.

$3

`javascript
await setTraits(traits)
`

Can only be used once a user has been identified, to set the value of the multiple traits for that user. Traits set to a value of null will be removed.

$3

`javascript
await incrementTrait(key, incrementBy)
``

Can only be used once a user has been identified, used to increment (or decrement) the specified trait for that user.