Question

The issue is simple: I need the version of IE. If it is 7 or earlier, I want to redirect. The code below works in all cases except when IE 8 accesses the page. It will work if IE 8 was not upgraded from 7. However, if it was upgraded, the value this returns is still 7, even though the About Internet Explorer help page shows the version as 8.0.etc.
I am stuck. Any ideas?

var BrowserDetect = {
init: function () {
    this.browser = this.searchString(this.dataBrowser) || "An unknown browser";
    this.version = this.searchVersion(navigator.userAgent)
        || this.searchVersion(navigator.appVersion)
        || "an unknown version";
    this.OS = this.searchString(this.dataOS) || "an unknown OS";
},
searchString: function (data) {
    for (var i = 0; i < data.length; i++) {
        var dataString = data[i].string;
        var dataProp = data[i].prop;
        this.versionSearchString = data[i].versionSearch || data[i].identity;
        if (dataString) {
            if (dataString.indexOf(data[i].subString) != -1)
                return data[i].identity;
        }
        else if (dataProp)
            return data[i].identity;
    }
},
searchVersion: function (dataString) {
    var index = dataString.indexOf(this.versionSearchString);
    if (index == -1) return;
    return parseFloat(dataString.substring(index + this.versionSearchString.length + 1));
},
dataBrowser: [
    {
        string: navigator.userAgent,
        subString: "Chrome",
        identity: "Chrome"
    },
    { string: navigator.userAgent,
        subString: "OmniWeb",
        versionSearch: "OmniWeb/",
        identity: "OmniWeb"
    },
    {
        string: navigator.vendor,
        subString: "Apple",
        identity: "Safari",
        versionSearch: "Version"
    },
    {
        prop: window.opera,
        identity: "Opera"
    },
    {
        string: navigator.vendor,
        subString: "iCab",
        identity: "iCab"
    },
    {
        string: navigator.vendor,
        subString: "KDE",
        identity: "Konqueror"
    },
    {
        string: navigator.userAgent,
        subString: "Firefox",
        identity: "Firefox"
    },
    {
        string: navigator.vendor,
        subString: "Camino",
        identity: "Camino"
    },
    {       // for newer Netscapes (6+)
        string: navigator.userAgent,
        subString: "Netscape",
        identity: "Netscape"
    },
    {
        string: navigator.userAgent,
        subString: "MSIE",
        identity: "Explorer",
        versionSearch: "MSIE"
    },
    {
        string: navigator.userAgent,
        subString: "Gecko",
        identity: "Mozilla",
        versionSearch: "rv"
    },
    {       // for older Netscapes (4-)
        string: navigator.userAgent,
        subString: "Mozilla",
        identity: "Netscape",
        versionSearch: "Mozilla"
    }
],
dataOS: [
    {
        string: navigator.platform,
        subString: "Win",
        identity: "Windows"
    },
    {
        string: navigator.platform,
        subString: "Mac",
        identity: "Mac"
    },
    {
        string: navigator.userAgent,
        subString: "iPhone",
        identity: "iPhone/iPod"
    },
    {
        string: navigator.platform,
        subString: "Linux",
        identity: "Linux"
    }
]

};
BrowserDetect.init();


var x = (BrowserDetect.browser);
var y = (BrowserDetect.version);
var z = (BrowserDetect.OS);

Y is still returning the version equaling 7, when IE is actually 8. However, this only happens on IE 8 when it has been upgraded from IE 7. It’s driving me nuts. Why isn’t it seeing the current browser equaling 8…

Answer 1

If you absolutely must detect browsers, use conditional comments to target only IE:

<!--[if lte IE 7]>
    <script type="text/javascript">
        window.location.href = "http://www.go-away-ie7.com/"
    </script>
<![endif]-->