Flyd React

Minimal React bindings for Flyd.

Installation

npm install flyd-react --save

Requirements

Since this library depends on React Hooks API, React version should be higher than 16.8.

Tutorial

Stream Connection

connect function connects a stream to a component state internally and returns current value of the state. The connected state will be updated automatically when the stream emits a new value.

import flyd from "flyd";
import every from "flyd/module/every";
import React from "react";
import { render } from "react-dom";
import { connect } from "flyd-react";

// An example stream which updates every second.
const everySecond = every(1000);
const stream = flyd.scan(n => n + 1, 0, everySecond);

// A container which connects to the stream.
const Container = () => {
  const childProps = {
    count: connect(stream)
  };
  return React.createElement(View, childProps);
};

// A view which displays the count.
const View = ({ count }) => <p>{count}</p>;

// Mount the container.
render(React.createElement(Container), document.getElementById("app"));

Lifecycle Optimization

Skip Reconnection

connect accepts "dependency values" as React's useEffect does. Passing appropriate deps might be effective when it is in a performance critical case. For most streams, connecting once when a component is mounted is enough. Passing [] as a second argument skips all the subsequent connection after mount.

import { connect } from "flyd-react";

// Using `[]` as deps skips all the subsequent connection.
const Container = () => {
  const childProps = {
    count: connect(
      stream,
      []
    )
  };
  return React.createElement(View, childProps);
};

Selective Stream

In the following example, passing [streamKey] as deps only reconnects when streamKey changes. Note that passing [] will cause problems in this case because given that deps, connect skips reconnecting to a new stream even when a new streamKey is set.

import { connect } from "flyd-react";

const streams = {
  one: flyd.stream(1),
  two: flyd.stream(2)
};

const Container = ({ streamKey }) => {
  const childProps = {
    count: connect(
      streams[streamKey],
      [streamKey]
    )
  };
  return React.createElement(View, childProps);
};