react-lazy-mount

Lazily mount react components to render after an initial condition is met.

Install

npm install --save react-lazy-mount
or 
yarn add react-lazy-mount

Idea

Sometimes you don't want to load something until an initial condition is met. If you have an expensive component that is making api calls, or is rendering lots of children, initial and frequent mounting can hinder performance. LazyMount can help improve performance by mounting components based on an initial condition. It's like lazy loading, but instead of waiting for an initial render to load the module, it is waiting for an initial truthy conditional in order to render JSX.

Simple Example

import React from 'react';
import LazyMount from 'react-lazy-mount';

export const Example = () => {
  const [state, setState] = useState(false);

  return (
    // once trigger prop becomes "true" for the first time, 
    // the children props are mounted and will stay mounted 
    // regardless of state changes.
    <LazyMount trigger={state} >
      <div >I'm mounted</div>
    </LazyMount>
  );
};

In the above example, <div >I'm mounted</div> is only rendered after the state becomes true for the first time. If the state becomes false, LazyMount will still render the children. It waits for the first true value of the trigger, and then mounts the children.

Coupled with lazy loading

import React from 'react';
import LazyMount from 'react-lazy-mount';
const MyComponent = React.lazy(() => import('./MyComponent'));

export const Example = () => {
  const [state, setState] = useState(false);

  return (
    // once trigger prop becomes "true" for the first time, 
    // mycomponent will be lazy loaded, then mounted
    <LazyMount trigger={state} fallback={...} >
      <MyComponent />
    </LazyMount>
  );
};

Lazy mounting can be coupled with lazy loading to wait for a condition to be met in order to both load the module and render the component. When given the fallback prop, the component will mount with lazy loading (Suspense).

Props	Type	Default Value	Description
trigger	Boolean	false	Trigger that listens for the first truthy value to render the children prop
children	ReactNode[]		Component(s) that will be mounted once the trigger becomes true for the first time, and stay mounted regardless of any future trigger changes.
fallback	NonNullable|null		Loads with suspense under the hood. Will render fallback during lazy loading

License

MIT © BenBrewerBowman

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This hook is created using create-react-hook.