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javascriptdomparameter-passingreplacesrc

updating a parameter within location (src) using JavaScript

How can I parse the value of status = 'logged-out' to the 3 tags below it, updating the value of login_status = 'logged-out'?

<script type="text/javascript">
      window.ndm = window.ndm || {};
      window.ndm.cam = {'status':'logged-out'};
</script>

<script src="http://foo.com/adserver/ndm/js.php?position=header-ad&amp;section_id=NEWS&amp;login_status=SUBSCRIBER"></script>
<script src="http://foo.com/adserver/ndm/js.php?position=middle-ad&amp;section_id=NEWS&amp;login_status=SUBSCRIBER"></script>
<script src="http://foo.com/adserver/ndm/js.php?position=footer-ad&amp;section_id=NEWS&amp;login_status=SUBSCRIBER"></script>

Keep in mind, there also heaps of other script tags on the page, so to identify the relevant ones. I got this function.

function getScriptSourceName(name){
var scripts = document.getElementsByTagName('script');
for (i=0;i<scripts.length;i++){
    if (scripts[i].src.indexOf(name) > -1)
        return scripts[i].src;
}}

Therefore to find the relevant script tags I want, i call the function - getScriptSourceName('foo.com');

How can I then update the login_status parameter's value to use the one declare at the very top?

Solution

  • I think this should work (below the HTML file for testing). Look at changeStatus method (I triggered it by button click for testing).

    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
    <script type="text/javascript">
      window.ndm = window.ndm || {};
      window.ndm.cam = {'status':'logged-out'};
    </script>

    <script src="http://foo.com/some.php?login_status=SUBSCRIBER"></script>
    <script src="http://foo.com/some.php?login_status=SUBSCRIBER"></script>
    <script src="http://foofoo01.com/some.php?login_status=SUBSCRIBER"></script>

    <script>
        function changeStatus(name)
        {
            var scripts = document.getElementsByTagName('script');
            var scriptsToChange = [];
            for (var i = 0; i < scripts.length; i++)
            {
                if (scripts[i].src.indexOf(name) > -1)
                {
                    var oldSrc = scripts[i].src;
                    var newSrc = oldSrc.replace(/(login_status=).*/,'$1' + 'logged-out');
                    scripts[i].setAttribute("src", newSrc);     
                    scriptsToChange.push(scripts[i]);               
                }
            }

            for (var k = 0; k < scriptsToChange.length; k++)
            {
                document.getElementsByTagName("head")[0].appendChild(scriptsToChange[k]);
            }
        }
    </script>
</head>
<body>      
    <button type="button" onclick="changeStatus('foo.com')">Change status</button>
</body>
</html>