npmcdn-to-unpkg-bot / react-visibility-sensor

Sensor component for React that notifies you when it goes in or out of the window viewport.

React Visibility Sensor

Sensor component for React that notifies you when it goes in or out of the window viewport.

Install

npm install react-visibility-sensor

Including the script directly

Useful if you want to use with bower, or in a plain old <script> tag.

In this case, make sure that React and ReactDOM are already loaded and globally accessible.

• Plain: https://npmcdn.com/[email protected]/dist/visibility-sensor.js
• Minified https://npmcdn.com/[email protected]/dist/visibility-sensor.min.js

Take a look at the umd example to see this in action

Example

View the example

To run the example locally:

• npm run build-example
• open example/index.html in a browser

General usage goes something like:

function render () {
  var VisibilitySensor = require('react-visibility-sensor');

  var onChange = function (isVisible) {
    console.log('Element is now %s', isVisible ? 'visible' : 'hidden');
  };

  return (
    <VisibilitySensor onChange={onChange} />
  );
}

Props

• onChange: callback for whenever the element changes from being within the window viewport or not. Function is called with 1 argument (isVisible: boolean)
• active: (default true) boolean flag for enabling / disabling the sensor. When active !== true the sensor will not fire the onChange callback.
• partialVisibility: (default false) consider element visible if only part of it is visible. Also possible values are - 'top', 'right', 'bottom', 'left' - in case it's needed to detect when one of these become visible explicitly.
• minTopValue: (default false) consider element visible if only part of it is visible and a minimum amount of pixels could be set, so if at least 100px are in viewport, we mark element as visible.
• delay: (default 1000) integer, number of milliseconds between checking the element's position in relation the the window viewport. Making this number too low will have a negative impact on performance.
• containment: (optional) element to use as a viewport when checking visibility. Default behaviour is to use the browser window as viewport.
• delayedCall: (default false) if is set to true, wont execute on page load ( prevents react apps triggering elements as visible before styles are loaded )

Thanks

Special thanks to contributors:

• @B-Stefan
• @kof
• @gaearon
• @kompot
• @EugeneHlushko

License

MIT