jquery-visible-rails

Installation

In your Gemfile, add the following line:

gem 'jquery-visible-rails'

Now run bundle install

Usage

Add this to your application.js.erb

//= require jquery
//= require jquery.visible

Add event handlers for the page becoming visible or hidden:

This basic check will return true if the entire element is visible to the user (within the visual viewport).

$('#element').visible();

If you'd like to check for ANY PART of the element, you can use the following:

$('#element').visible( true );

The plugin ignores the elements visibility by default. E.g., display:none, visibility: hidden, offsetWidth or offsetHeight is 0). To filter on css visibility, you can use the jQuery :visible selector:

  $('#element:visible').visible();

Optionally, you can sepecify a second parameter to the .visible plugin, which will check whether the element is visible, as well as whether it's within the viewport too.

$('#element:visible').visible( false, true );

Optionally, you can add a third parameter to specify the direction to check for visibility. This can either be 'horizontal', 'vertical' or 'both'. Default is to 'both'.

$('#element').visible( false, false, 'horizontal' );

More information

• jquery-visible