next-lazy-component

Install

npm install next-lazy-component

Usage

import lazyLoadComponent from 'next-lazy-component';

// Lazy hydrate when visible
const WhyUs = lazyLoadComponent(() => import('../components/whyus'));

// Lazy hydrate when users hover into the view
const Footer = lazyLoadComponent(
  () => import('../components/footer', { on: ['mouseover'] })
);

const HomePage = () => {
  return (
    <div>
      <AboveTheFoldComponent />
      {/* ----The Fold---- */}
      <WhyUs />
      <Footer />
    </div>
  );
};

API

lazyLoadComponent(dynamicImport, options?)

dynamicImport

Type: () => Promise<React.ComponentType>

A function return import() in dynamic loading type

Options

on: Array

An array of events who will trigger the hydration. Can contains event names directly or as an array of ['event name', options].

import lazyLoadComponent from 'next-lazy-component';

const Card = lazyLoadComponent(() => import('../Card'), {
  on: ['visible', ['scroll', () => document], ['delay', 5000]],
});

Support all DOM events and more :

| Event name | Options | Description | | ------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------ | | all DOM events | getTarget: Function who return the event target (default: the wrapped component) | | delay | delay: Number in ms (default value: 2000) | Scheduled hydration. | | visible | getOptions: Function who return an intersectionObserver options object (default: no options) | Requires IntersectionObserver. Polyfill not included. If unsupported the component is directy hydrated. | | idle | | Requires requestIdleCallback. Polyfill not included. If unsupported the component will be hydrated with a delay of 2000ms. |

compatibleMode: Boolean (optional, default: false)

Set it to true if your component use Context.

Rule of thumb: If the component render error, turn compatibleMode = true;

whenInputPending: Boolean (optional, default: false)

When set to true use navigator.scheduling.isInputPending to check if there is a pending user input on mount. If that's the case, hydration will be delayed using the strategies defined in the on option to allow the browser to handle the user input. If there is no pending input, the component will be hydrated directly to be interactive as fast as possible.

See https://github.com/WICG/is-input-pending for more infos.

isInputPendingFallbackValue: Boolean (optional, default: true)

The default value returned on browsers who don't implements navigator.scheduling.isInputPending when whenInputPending set to true.

disableFallback: Boolean (optional, default: false)

If set at true the component will not be rendered client side if not rendered server side.

Props

wrapperProps: Object (optional)

Props that are applied to the div which wraps the provided component.

import lazyLoadComponent from 'next-lazy-component';
import Card from '../Card';

const Card = lazyLoadComponent(() => import('../Card'), {
  on: ['delay'],
});

const App = () => {
  return (
    <Card
      title="my card"
      wrapperProps={{
        className: 'customClassName',
        style: { display: 'contents' },
      }}
    />
  );
};

forceHydration: Boolean (optional, default: false)

Force the hydration of the component.