JavaScript Regex to return the last digits and ASP.Net event Handler?

Question

Given the following string: 's0\\8\\26\\29\\30\\32' or 's0\\8\\26\\' or 's0\\5', I need to return the last digits of the string.

Given:

 function getFolderID(mystr) {
        var reFolderID = /\bs0\\\\[0-9]+\b/g //regexp to return s0\\34
        var retArr = [];
        var retval = '';

        retArr = mystr.match(reFolderID);
        retArr = retArr[0].replace(/s0\\\\/g, "");

        if (retArr != null) {
            retval = retArr[retArr.length - 1];
        }
        //alert("Ret: " + retval);
        return retval;
    }  

At first I thought I just needed the first digits, but turns out I need the last ones.

What would the proper regexp term be for this?

Also, how can I create an ASP.Net event handler to do something with the returned JS value?

Answer 1

You might try the following. It should following the formatting and group the last set of numbers.

/s0\\\\(?:[0-9]+\\\\)*([0-9]+)/

So, something like:

function getFolderID(mystr) {
    // search string for last group of digits in the pattern
    var matches = mystr.match(/s0\\\\(?:[0-9]+\\\\)*([0-9]+)/);

    // if matches is null, replace with "defaults"
    matches ||= ["", ""];

    // grab the first grouped match
    return matches[1];
}

---

As for the ASP.NET event, you'll probably have to use Ajax -- such as by <asp:UpdatePanel /> or your choice of Ajax library (jQuery, Prototype, etc.).

Without Ajax, JavaScript and ASP.NET will never execute at the same time.

Answer 2

You could match the last digits in a string this way:

function getFolderId(str) {
    var pattern = /([0-9]+)$/;
    var result = pattern.exec(str);
    return result ? result[1] : null;
}

Answer 3

On the issue of returning Javascript parameters to the server...

I created two ASP.Net hidden fields, then in JS, set the values of these fields... voila - available from my code-behind:

    // set .net hidden control values so they're server-side accessible
    document.getElementById('ctl00_ContentPlaceHolderMainBody_HidTreeContextAction').value = buttonAction;
    document.getElementById('ctl00_ContentPlaceHolderMainBody_HidTreeContextID').value = buttonFolder;

And

<asp:HiddenField ID="HidTreeContextAction" runat="server" />
<asp:HiddenField ID="HidTreeContextID" runat="server" />

Now the workflow is: 1) user right-clicks on tree node 2) context menu appears 3) selecting a context menu item fires the JS that sets the hidden values 4) ajax-style window appears to accept user input 5) user clicks submit 6) both parameters are used do determine what/where the data goes

I realize this may be a bit of a hack, and not using AJAX. If someone cares to share how this would be done ajax-style, great!

Just thought I'd share this quick fix in case anyone else needs it.