refract-callbag

Master your React app's effects through the
power of reactive programming.

Why? · Install · The gist · Learn · Contribute · Discuss

Refract lets you isolate your app's side effects - API calls, analytics, logging, etc - so that you can write your code in a clear, pure, and declarative fashion by using reactive programming.

Refract is an extensible library built for React. In addition we provide a Redux integration, which can also serve as a template for integrations with other libraries.

Why?

Component-based architecture and functional programming have become an increasingly popular approach for building UIs. They help make apps more predictable, more testable, and more maintainable.

However, our apps don't exist in a vacuum! They need to make network requests, handle data persistence, log analytics, deal with changing time, and so on. Any non-trivial app has to handle any number of these external effects.

These side-effects hold us back from writing fully declarative code. Wouldn't it be nice to cleanly separate them from our apps?

Refract solves this problem for you. For an in-depth introduction, head to Why Refract.

Installation

npm install --save refract-callbag

Refract is available for a number of reactive programming libraries. For each library, a Refract integration is available for both React and Redux.

Available packages:

	React	Redux
Callbag	refract-callbag	refract-redux-callbag
Most	refract-most	refract-redux-most
RxJS	refract-rxjs	refract-redux-rxjs
xstream	refract-xstream	refract-redux-xstream

The Gist

The example below uses refract-rxjs to send data to localstorage.

Every time the username prop changes, its new value is sent into the stream. The stream debounces the input for two seconds, then maps it into an object (with a type of localstorage) under the key value. Each time an effect with the correct type is emitted from this pipeline, the handler calls localstorage.setItem with the effect's name and value properties.

const aperture = initialProps => component => {
    return component.observe('username').pipe(
        debounce(2000),
        map(username => ({
            type: 'localstorage',
            name: 'username',
            value: username
        }))
    )
}

const handler = initialProps => effect => {
    switch (effect.type) {
        case 'localstorage':
            localstorage.setItem(effect.name, effect.value)
            return
    }
}

const WrappedComponent = withEffects(handler)(aperture)(BaseComponent)

Aperture

An aperture controls the streams of data entering Refract. It is a function which observes data sources within your app, passes this data through any necessary logic flows, and outputs a stream of effects.

Signature: (initialProps) => (component) => { return effectStream }.

• The initialProps are all props passed into the WrappedComponent.
• The component is an object which lets you observe your React component.
• Within the body of the function, you observe the event source you choose, pipe the events through your stream library of choice, and return a single stream of effects.

Handler

A handler is a function which causes side-effects in response to any effect object output by the aperture.

Signature: (initialProps) => (effect) => { /* handle effects here */ }.

• The initialProps are all props passed into the WrappedComponent.
• The effect is each event emitted by your aperture.
• Within the body of the function, you call any side-effects imperatively.

withEffects

The withEffects higher-order component implements your side-effect logic as a React component.

Signature: (handler) => (aperture) => (Component) => { return WrappedComponent }

• The hoc takes in three curried arguments:
  • A handler function
  • An aperture function
  • A React Component
• The hoc returns a WrappedComponent - an enhanced version of your original Component which includes your side-effect logic.

Documentation

Links through to docs sub-pages.

Examples

Contributing

We welcome many forms of contribution from anyone who wishes to get involved.

Before getting started, please read through our contributing guidelines and code of conduct.

Links

Logo

The Refract logo is available in the Logo directory.

License

Refract is available under the MIT license.

Discuss

Everyone is welcome to join our discussion channel - #refract on the Reactiflux Discord server.