Question

If the current page URL has an argument ‘myid1’ in the querystring, for each link in my webpage with class ‘rewrite’, I want the link href’s querystring to be replaced by the current page URL’s querystring.

I’m using the following code:

<script type='text/javascript' src='https://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js'></script>

<script type="text/javascript">
            $(function() {
                var requestid = new String(gup('myid1'));
                if (requestid!=null&&requestid!="") {
                $("a.rewrite").each(function() {
                    var href = $(this).attr("href");
                    href += "?myid1=" + requestid;
                    $(this).attr("href", href);
                 })
               }
            })
            //gup taken from here:http://www.netlobo.com/url_query_string_javascript.html
            function gup(name) {
                name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
                var regexS = "[\\?&]" + name + "=([^&#]*)";
                var regex = new RegExp(regexS);
                var results = regex.exec(window.location.href);
                if (results == null)
                    return "";
                else
                    return results[1];
            }
</script>

<a href="http://www.otherdomain.com?someid=1234" class="rewrite">Hyperlink</a>

The problem is that the URS’s querystring is being added to the links without removing the existing one. How to fix it?

Also, how do I allow one more parameter called ‘myid2’. Thank you in advance for your help.

Answer 1

You can remove a prefious query string with this:

$(function() {
    var requestid = gup('myid1');
    if (requestid) {
        $("a.rewrite").each(function() {
            var base = this.href;
            var pos = base.indexOf("?");
            if (pos != -1) {
                base = base.substr(0, pos);
            }
            this.href = base + "?myid1=" + requestid;
        })
    }
})

Several things to note in this revision:

1. if (requestid) tests for null, undefined and "" so you can use just the one test.
2. There is no need to use a jQuery object to access the href attribute. It’s faster and more direct to just use this.href.

If you like fewer lines of code (though not quite as fast), you would do it this way:

$(function() {
    var requestid = gup('myid1');
    if (requestid) {
        $("a.rewrite").each(function() {
            this.href = this.href.replace(/\?.*$/, "") + "?myid1=" + requestid;
        })
    }
})