browser-detect.js

/**
 * This method is used to detect the user browser and environment
 */
establishBrowser() {
        const userAgent = (navigator && navigator.userAgent || '').toLowerCase()
        const vendor = (navigator && navigator.vendor || '').toLowerCase()

        const comparator = {
            '<': function(a, b) { return a < b; },
            '<=': function(a, b) { return a <= b; },
            '>': function(a, b) { return a > b; },
            '>=': function(a, b) { return a >= b; }
        };

        const compareVersion = (version, range) => {
            const str = (range + '');
            const n = +(str.match(/\d+/) || NaN);
            const op = str.match(/^[<>]=?|/)[0];
            return comparator[op] ? comparator[op](version, n) : (version == n || n !== n);
        };

        this.browser = {
            userAgent,
            vendor,
        };

        // detect opera
        this.browser.isOpera = function isOpera(range) {
            const match = userAgent.match(/(?:^opera.+?version|opr)\/(\d+)/);
            return match !== null && compareVersion(match[1], range);
        }

        // detect chrome
        this.browser.isChrome = function isChrome(range) {
            const match = /google inc/.test(vendor) ? userAgent.match(/(?:chrome|crios)\/(\d+)/) : null;
            return match !== null && !this.isOpera() && compareVersion(match[1], range);
        }

        // detect firefox
        this.browser.isFirefox = function isFirefox(range) {
            const match = userAgent.match(/(?:firefox|fxios)\/(\d+)/);
            return match !== null && compareVersion(match[1], range);
        };

        // detect safari
        this.browser.isSafari = function isSafari(range) {
            const match = userAgent.match(/version\/(\d+).+?safari/);
            return match !== null && compareVersion(match[1], range);
        };

        // detect internet explorer
        this.browser.isIE = function isIE(range) {
            const match = userAgent.match(/(?:msie |trident.+?; rv:)(\d+)/);
            return match !== null && compareVersion(match[1], range);
        };

        // detect edge
        this.browser.isEdge = function isEdge(range) {
            const match = userAgent.match(/edge\/(\d+)/);
            return match !== null && compareVersion(match[1], range);
        };

        // detect blink engine
        this.browser.isBlink = function isBlink() {
            return (this.isChrome() || this.isOpera()) && !!window.CSS;
        };
    }