Question

I have a client global variable in javascript. I need to access this global variable from the server side which is living on different page. how can i achieve this without a query string? if session state required, then how can i set the session from the javascript?

EDITED

ok.. here is the full scenario.. the page itself is a sharepoint web page, i have only control on the web part. within the webpart i have a button that does window.open to open another page. Now how can i pass the javascript variable from the main page to the other page and make it accessible in the code-behind?

Answer 1

I can think of a few ways to do it, but I’ll recommand you this. The basic steps are:

1. Use JavaScript to popup a modal dialog alone with the global variable you want to pass as a argument (not query string).

2. On the popup page, use JavaScript to set the global variable to a hidden field and then initiate a postback to itself.

3. At code behind, retrieve the global variable from hidden field and store it in session data.

4. Now, the global variable is available in Session space.

Note: You’ll need jQuery 1.7.1 or higher.

Step 1 code:

this is your popup link or button.

<a id="popAspxWeb" href="#" onclick="javascript:PopPage('ModalPopup.aspx','galbal_variable_data');">Click to Popup</a>

here’s the javascript code to open popup window.

<script type="text/javascript">
    function PopPage(page, data) {
        var result = window.showModalDialog(
        page, // popup this page
        data, // with this data
        "dialogWidth:500px; dialogHeight:500px; resizable:no; status:no; center:yes");
    }
</script>

Step 2 code:

you’ll need these. first one to store the data get passed in and second one to flag page postback or not.

<input id="hidData" runat="server" type="hidden" />
<input id="postback" runat="server" type="hidden" value="false" />

here’s the javascript:

<script type="text/javascript">
    var data = ""; // global variable to store data from parent window.

    $(document).ready(function() { //jQuery code to be executed when document is fully loaded.
        args = window.dialogArguments; // obtain argument data and assign to global variable.
        if ($("#postback").val().toString() == "false") { // if first visit to page
            $("#hidData").val(data); // assign argument data from global variable to hidden field.
            $("#postback").val("true"); // flag the form is posted back.
            document.forms[0].submit(); // trigger form post.
        }
    });

    function ReturnAndClose() { // you can optionally return data back to the parent window.
        window.close(); // this closes modal pop up.
        window.returnValue = document.getElementById('return_data').value; // this returns a value to parent window.
    }

</script>

Step 3 code:

code behine to access galbol variable data.

protected void Page_Load(object sender, EventArgs e)
{
    if (Page.IsPostBack)
    {
        string data = this.hidData.Value;
        this.Session["data"] = data;
    }
}