React Molasses

It includes the React (with TypeScript support) SDK for Molasses. It allows you to evaluate a user's status for a feature. It also helps simplify logging events for A/B testing.

react-molasses offers a provider with hooks and with support. Once initialized, it takes microseconds to evaluate if a user is active. react-molasses does rely on molasses-js as a client.

Install

npm install @molassesapp/molasses-js react-molasses

yarn add @molassesapp/molasses-js react-molasses

Usage

To Require:

import { MolassesClient } from "@molassesapp/molasses-js"
import { MolassesProvider } from "react-molasses"

Initialize the same way you would with molasses-js, but wrap your main application in the MolassesProvider

// Initialize with your API Key
const client = new MolassesClient({
  APIKey: "testapikey",
})

// Then init which is a promise
client.init().then(() => {
  const AppContainer = () => {
    return (
      <MolassesProvider client={client}>
        <Router>
          <App />
        </Router>
      </MolassesProvider>
    )
  }

  ReactDOM.render(<AppContainer />, document.getElementById("root"))
})

Once it's initialized, you can then use Molasses in any component using React's context api. We've created a set of hooks and components to make this easier for you.

---

Components and Hooks

MolassesProvider

Wraps any children and provides the MolassesClient in the React.context. Molasses must be initialized before it can be used.

Props

Prop	required	type	description
client	required	MolassesClient	the initialized MolassesClient to pass into the react context

<Feature name="NAME" user={user}>

A component to evaluate a Feature by name. It can be used in several different ways, declarative using children, function based and using the render prop.

Props

Prop	required	type	description
name	required	string	The name of the feature to be evaluated
user	optional	User	The user who to evaluate against
render	optional	Function | JSX.Element	What to render based on the result of the evaluation
render	optional	Function | JSX.Element	What to render based on the result of the evaluation

Examples

const Component = (props) => (
  <Feature name="NEW_CHECKOUT" user={user}>
    <div>I'll render if NEW_CHECKOUT is active for that user</div>
  </Feature>
)

const ComponentB = (props) => (
  <Feature
    name="NEW_CHECKOUT"
    user={user}
    render={(isActive: boolean) => {
      return isActive ? <span>I'll render if I'm active</span> : <span>I won't</span>
    }}
  />
)

const ComponentC = (props) => (
  <Feature name="NEW_CHECKOUT" user={user}>
    {(isActive: boolean) => {
      return isActive ? <span>I'll render if I'm active</span> : <span>I won't</span>
    }}
  </Feature>
)

useFeature(name: string, user: User): boolean

A hook to determine if a given feature is active for a User. Uses the Molasses context under the hood

useMolasses(): MolassesClient

A hook to expose the Molasses client to a component

withMolasses(Component: React Component)

A HOC that passes the MolassesClient as the prop molasses to the component

Example

const comp = (props) => {
  const isActive = props.molasses.isActive("FOO_TEST")
  return isActive ? <h1>active</h1> : <h1>off</h1>
}
const Component = withMolasses(comp)