bottom_popup.js

var $ = require( 'jquery' ),
    throttle = require( 'modules/throttle' );

module.exports = function( el ) {
    var $el = $( el ),
        $window = $( window ),
        $bar = $( '#bottom-bar' ),
        $close = $bar.find('.close-icon'),
        $footer = $( '.footer' );

    // Add session to display once per session
    if (sessionStorage.getItem('bottom-bar') !== 'true') {
        // Show bottom bar
        $window.on('scroll', throttle(function() {
            var scroll = $(this).scrollTop();
            // Condition: Begin scroll + hide when move to footer
            if (scroll > 1 && scroll + $window.height() < $footer.offset().top ) {
                $bar.removeClass('hide');
            } else {
                $bar.addClass('hide');
            }
        }, 50));
    }

    // Close bottom bar
    $close.on( "click", function(e) {
        e.preventDefault();
        sessionStorage.setItem('bottom-bar', 'true');
        $bar.remove();
    });

};