legacy-browser-detection-ua-sniffing.js

legacy-browser-detection-ua-sniffing.js

(function() {

    var isIE = typeof document.documentMode !== 'undefined'
  
    var chromeVersion = navigator.userAgent.match(/Chrome\/(\d+)/) || undefined
    chromeVersion = chromeVersion && parseInt(chromeVersion[1])
  
    var firefoxVersion = navigator.userAgent.match(/Firefox\/(\d+)/) || undefined
    firefoxVersion = firefoxVersion && parseInt(firefoxVersion[1])
  
    var edgeVersion = navigator.userAgent.match(/Edge\/(\d+)/) || undefined
    edgeVersion = edgeVersion && parseInt(edgeVersion[1])
  
    var safariVersion = (!chromeVersion && !navigator.userAgent.match(/Tizen/)
      && navigator.userAgent.match(/Version\/(\d+).*Safari\//))
      || undefined
  
    safariVersion = safariVersion && parseInt(safariVersion[1])
  
    // Checking precisely for Safari version = 9 because there are too many false positives
    // from niche browsers having Version/4 or Version/5 in URL (old Androids, Samsung TV WebViews...)
    var isLegacy = isIE || chromeVersion < 47 || firefoxVersion < 48 || edgeVersion < 17 || safariVersion === 9
 
    if (isLegacy) {
        // ...
    }
  })();