JSPM

lazy-preload wraps the React.lazy() API and adds the ability to preload the component before it is rendered for the first time.

Install

npm install lazy-preload

Usage

Before:

import {
    lazy,
    Suspense
} from "react";
const LazyLoadComponent = lazy(() => import("./LazyLoadComponent"));

After:

import {
    Suspense
} from "react";
import {
    lazyWithPreload
} from "lazy-preload";
const LazyLoadComponent = lazyWithPreload(() => import("./LazyLoadComponent"));

// ...
LazyLoadComponent.preload();

To preload a component before it is rendered for the first time, the component that is returned from lazy() has a preload function attached that you can invoke. preload() returns a Promise that you can wait on if needed. The promise is idempotent, meaning that preload() will return the same Promise instance if called multiple times.

For more information about React code-splitting, React.lazy and React.Suspense , see https://reactjs.org/docs/code-splitting.html.

Example

For example, if you need to load a component when a button is pressed, you could start preloading the component when the user hovers over the button:

import { lazyWithPreload, LazyLoadComponent } from 'lazy-preload';
const Component = lazyWithPreload(() => import("./component"));

export function render() {
  return <LazyLoadComponent
        defaultLoadComponent={<>Icon</>}
        loading={<div>Loading</div>}
        lazyLoadComponent={Component}
    >
        <Component  {...options} />
    </LazyLoadComponent>
}

Acknowledgements

Inspired by the preload behavior of react-loadable and react-lazy-with-preload.