https://www.dwr.com/on/demandware.static/Sites-dwr-Site/-/en_US/v1790241915285/js/polyfills.js

1/**
2 * Feature detect and conditionally load polyfills for outdated browsers
3 */
4(function () {
5    function loadScript(src) {
6        var firstScript = document.querySelector('script');
7        var newScript = document.createElement('script');
8
9        newScript.src = src;
10        newScript.defer = true;
11
12        if (firstScript) {
13            // insert new script after first script tag
14            firstScript
15                .parentNode
16                .insertBefore(newScript, firstScript.nextSibling);
17        }
18    }
19
20    /**
21     * Check to see if the browser fully supports IntersectionObserver
22     * @returns {boolean} - Whether or not the browser fully supports IntersectionObserver
23     */
24    function supportsIntersectionObserver() {
25        if (!('IntersectionObserver' in window) ||
26            !('IntersectionObserverEntry' in window) ||
27            !('intersectionRatio' in window.IntersectionObserverEntry.prototype) ||
28            !('isIntersecting' in window.IntersectionObserverEntry.prototype)) {
29            return false;
30        }
31
32        return true;
33    }
34
35    /**
36     * Check to see if the browser supports sticky position value
37     * @returns {boolean} - Whether or not the browser supports the sticky position
38     */
39    function supportsPositionSticky() {
40        var prop = 'position:';
41        var value = 'sticky';
42        var prefixes = ' -webkit- -moz- -o- -ms- '.split(' ');
43
44        var el = document.createElement('a');
45        var mStyle = el.style;
46        mStyle.cssText = prop + prefixes.join(value + ';' + prop).slice(0, - prop.length);
47
48        return mStyle.position.indexOf(value) !== -1;
49    };
50
51    if (!supportsPositionSticky()) {
52        loadScript(window.__staticPath__ + 'js/lib/stickyfill.min.js');
53    }
54
55    if (!supportsIntersectionObserver()) {
56        loadScript(window.__staticPath__ + 'js/lib/intersection-observer.min.js');
57    }
58})();