function detect()

in blog/assets/js/plugins/md-env.js [15:79]

• 53 lines of code
• 55 McCabe index (conditional complexity)

    function detect(ua) {
        var os = this.os = {};
        var browser = this.browser = {};
        var webkit = ua.match(/Web[kK]it[\/]{0,1}([\d.]+)/);
        var android = ua.match(/(Android);?[\s\/]+([\d.]+)?/);
        var ipad = ua.match(/(iPad).*OS\s([\d_]+)/);
        var ipod = ua.match(/(iPod)(.*OS\s([\d_]+))?/);
        var iphone = !ipad && ua.match(/(iPhone\sOS)\s([\d_]+)/);
        var webos = ua.match(/(webOS|hpwOS)[\s\/]([\d.]+)/);
        var touchpad = webos && ua.match(/TouchPad/);
        var kindle = ua.match(/Kindle\/([\d.]+)/);
        var silk = ua.match(/Silk\/([\d._]+)/);
        var blackberry = ua.match(/(BlackBerry).*Version\/([\d.]+)/);
        var bb10 = ua.match(/(BB10).*Version\/([\d.]+)/);
        var rimtabletos = ua.match(/(RIM\sTablet\sOS)\s([\d.]+)/);
        var playbook = ua.match(/PlayBook/);
        var chrome = ua.match(/Chrome\/([\d.]+)/) || ua.match(/CriOS\/([\d.]+)/);
        var firefox = ua.match(/Firefox\/([\d.]+)/);
        var ie = ua.match(/MSIE ([\d.]+)/);
        var safari = webkit && ua.match(/Mobile\//) && !chrome;
        var webview = ua.match(/(iPhone|iPod|iPad).*AppleWebKit(?!.*Safari)/) && !chrome;
        var ie = ua.match(/MSIE\s([\d.]+)/);

        // Todo: clean this up with a better OS/browser seperation:
        // - discern (more) between multiple browsers on android
        // - decide if kindle fire in silk mode is android or not
        // - Firefox on Android doesn't specify the Android version
        // - possibly devide in os, device and browser hashes

        if (browser.webkit = !!webkit) browser.version = webkit[1];

        if (android) os.android = true, os.version = android[2];
        if (iphone && !ipod) os.ios = os.iphone = true, os.version = iphone[2].replace(/_/g, '.');
        if (ipad) os.ios = os.ipad = true, os.version = ipad[2].replace(/_/g, '.');
        if (ipod) os.ios = os.ipod = true, os.version = ipod[3] ? ipod[3].replace(/_/g, '.') : null;
        if (webos) os.webos = true, os.version = webos[2];
        if (touchpad) os.touchpad = true;
        if (blackberry) os.blackberry = true, os.version = blackberry[2];
        if (bb10) os.bb10 = true, os.version = bb10[2];
        if (rimtabletos) os.rimtabletos = true, os.version = rimtabletos[2];
        if (playbook) browser.playbook = true;
        if (kindle) os.kindle = true, os.version = kindle[1];
        if (silk) browser.silk = true, browser.version = silk[1];
        if (!silk && os.android && ua.match(/Kindle Fire/)) browser.silk = true;
        if (chrome) browser.chrome = true, browser.version = chrome[1];
        if (firefox) browser.firefox = true, browser.version = firefox[1];
        if (ie) browser.ie = true, browser.version = ie[1];
        if (safari && (ua.match(/Safari/) || !!os.ios)) browser.safari = true;
        if (webview) browser.webview = true;
        if (ie) browser.ie = true, browser.version = ie[1];

        os.tablet = !!(ipad || playbook || (android && !ua.match(/Mobile/)) ||
            (firefox && ua.match(/Tablet/)) || (ie && !ua.match(/Phone/) && ua.match(/Touch/)));
        os.phone  = !!(!os.tablet && !os.ipod && (android || iphone || webos || blackberry || bb10 ||
            (chrome && ua.match(/Android/)) || (chrome && ua.match(/CriOS\/([\d.]+)/)) ||
            (firefox && ua.match(/Mobile/)) || (ie && ua.match(/Touch/))));

        return {
            browser: browser,
            os: os,
            // 原生canvas支持，改极端点了
            // canvasSupported : !(browser.ie && parseFloat(browser.version) < 9)
            canvasSupported : document.createElement('canvas').getContext ? true : false
        };
    }