@lectra/ld-react-feature-flags
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Integrate Launch Darkly in your React app in a breeze
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# ld-react-feature-flags
[](https://travis-ci.org/lectra-tech/ld-react-feature-flags)
[](https://www.npmjs.com/package/@lectra/ld-react-feature-flags)
[](https://github.com/prettier/prettier)
> Integrate Launch Darkly in your React app in a breeze
## Install
This project requires **React 16.3.0 or later**.
To use ld-react-feature-flags with your React app, install it as a dependency:
```bash
npm install @lectra/ld-react-feature-flags
```
## Getting Started
### FlagsProvider
Wrap your root component with `FlagsProvider` to make LaunchDarkly client instance accessible to all children components thanks to React context.
```javascript
// React 17 and lower
import ReactDOM from 'react-dom';
import { FlagsProvider } from '@lectra/ld-react-feature-flags';
ReactDOM.render(
<FlagsProvider user={user} clientkey="myClientKey" loadingComponent ={<div>please wait</div>}>
<App />
</FlagsProvider>,
document.getElementById('root')
);
```
```javascript
// React 18 and higher
import { createRoot } from 'react-dom/client';
import { FlagsProvider } from '@lectra/ld-react-feature-flags';
const root = createRoot(document.getElementById('root'));
root.render(
<FlagsProvider user={user} clientkey="myClientKey" loadingComponent ={<div>please wait</div>}>
<App />
</FlagsProvider>
);
```
| Prop | Type | Required | Description |
|------------------|-----------|----------|------------------------------|
| user | Object | true | User information |
| clientkey | String | true | Your LaunchDarkly secret key |
| onFlagsChange | function | false | Handler for flag change |
| loadingComponent | Component | false | Loading component / string |
### Flags
All `Flags` components get the _ldClient_ instance thanks to the `FlagsProvider` component.
To render a node or a component based on your flags, you must pass a `flag` props.
The `Flags` component will ask to LaunchDarkly if the given flag is active or not, depending on you LaunchDarkly settings.
You have the control on what will be rendered:
* If the flag is active, you can wrapped the desired component to render as children to a Flag component or use a `renderOn` props.
* If the flag isn't active, nothing will be rendered unless you pass a component as fallback by the `fallbackRender` props.
| Prop | Type | Required | Description |
|----------------|-------------------|----------|-----------------------------------------------------------|
| flag | String | true | The flag to check |
| children | Element/Component | false | Return the component if the flag given by props is active |
| renderOn | Function | false | Return the given component if the flag is active |
| fallbackRender | Function | false | Return the given component if the flag is inactive |
#### with children props
```javascript
import { Flags } from '@lectra/ld-react-feature-flags';
<Flags
flag="beta-only"
>
<h4>for beta users</h4>
</Flags>
```
#### with renderOn props
```javascript
import { Flags } from '@lectra/ld-react-feature-flags';
<Flags
flag="beta-only"
renderOn={flag => <h4>for beta users</h4>}
/>
```
#### with renderOn props and fallbackRender props as fallback
```javascript
import { Flags } from '@lectra/ld-react-feature-flags';
<Flags
flag="beta-only"
renderOn={flag => <h4>for beta users</h4>}
fallbackRender={flag => (
<h4>for regular users</h4>
)}
/>
```
#### with multivariant flag
The flag given by props is a multivariant flag.
See the [LaunchDarkly doc](https://docs.launchdarkly.com/docs/managing-variations) for more details.
If the flag is active, LD won't return a boolean value but instead a custom value. In our case a string that represents a color.
We can use it directly to style our `h1` title.
```javascript
import { Flags } from '@lectra/ld-react-feature-flags';
<Flags
flag="header-bg-color"
renderOn={flag => {
return (
<h1 style={{ color: flag.headerBgColor }}>
My awesome multivariant flag
</h1>
);
}}
/>
```
### WithFlags
Same as `Flags` components but in a Higher Order Component way.
`WithFlags([flag])([ComponentToRenderIfTrue][ComponentToRenderIfFalse])`
| Arguments | Type | Required | Description |
|--------------------------|-----------------|----------|-----------------------------------------------------------------------------|
| flag | String | true | The flag to check |
| ComponentToRenderIfTrue | React Component | true | The React component to render if the flag is true or is a multivariant flag |
| ComponentToRenderIfFalse | React Component | false | The React component to render if the flag is false |
#### Component render based on flag value
```javascript
import { WithFlags } from '@lectra/ld-react-feature-flags';
const HBeta = () => <h4>for beta users</h4>;
const HeaderFeatureFlipped = WithFlags("beta-only")(HBeta)
<HeaderFeatureFlipped></HeaderFeatureFlipped>
```
#### Component render toggled on flag value
```javascript
import { WithFlags } from '@lectra/ld-react-feature-flags';
const HBeta = () => <h4>for beta users</h4>;
const HStandard = () => <h4>for standard users</h4>;
const HeaderFeatureFlipped = WithFlags("beta-only")(HBeta, HStandard)
<HeaderFeatureFlipped></HeaderFeatureFlipped>
```
#### Component render with multivariant flag
```javascript
import { WithFlags } from '@lectra/ld-react-feature-flags';
const HeaderWithColor = ({headerBgColor}) => (
<h1 style={{ color: headerBgColor }}>
My awesome multivariant flag
</h1>);
const HeaderFeatureFlippedWithColor = WithFlags("header-bg-color")(HeaderWithColor)
<HeaderFeatureFlippedWithColor></HeaderFeatureFlippedWithColor>
```
## Example
This project contains some examples that you could run.
```bash
git clone https://github.com/lectra-tech/ld-react-feature-flags.git
cd ld-react-feature-flags/example
npm install
npm start
```
## License
MIT