[Recompose] Stream a React Component from an Ajax Request with RxJS

Loading data using RxJS is simple using Observable.ajax. This lesson shows you how to take the ajax response and pass it along the stream to use as props in a React Component.

import React from "react"
import { render } from "react-dom"
import { Observable } from "rxjs"
import rxjsConfig from "recompose/rxjsObservableConfig"
import {
  setObservableConfig,
  componentFromStream
} from "recompose"

setObservableConfig(rxjsConfig)

const personById = id =>
  `https://swapi.co/api/people/${id}`

const Card = props => (
  <div>
    <h1>{props.name}</h1>
    <h2>{props.homeworld}</h2>
  </div>
)

const loadById = id =>
  Observable.ajax(personById(id))
    .pluck("response")
    .switchMap(
      response =>
        Observable.ajax(response.homeworld)
          .pluck("response")
          .startWith({ name: "" }),
      (person, homeworld) => ({
        ...person,
        homeworld: homeworld.name
      })
    )

const CardStream = componentFromStream(props$ =>
  props$
    .switchMap(props => loadById(props.id))
    .map(Card)
)

const App = () => (
  <div>
    <Card name="John" homeworld="Earth" />
    <CardStream id={1} />
    <CardStream id={12} />
    <CardStream id={10} />
    <CardStream id={24} />
  </div>
)

render(<App />, document.getElementById("root"))

SwitchMap has second param which is a selector function, take two params, first is outter observable, in the example refers to Person response, second is inner observable, in the example refer to homeworld response. Then combine to one single response.