Call Model function from javascript in razor page

Question

Is it possible to call a Model function in a razor page like this (the function is never hit):

<input id="btnWork" type="submit" value="Work" onclick="writeLog("add to log");" />

However, I have this in my razor page and it hits the function on page load only:

{
<script>
     function writeLog(msg)
     {
         @IndexModel.logHolder.Add("testing 123");
     }
</script>
}

Answer 1

I agree with Mike Brind. At the same time, I also did some testing work, which I also shared.

We can't call C# function from javascript directly, Because javascript execute on client side and C# function execute at server side. So we need to call it other way like AJAX.

Define your function in Model and call it via AJAX call.

JS Code:

<script>
   function writeLog(msg) {
      $.ajax({
        url: '?handler=WriteLog&msg='+msg,
        success: function (data) {
            alert(data);
        },
        error: function (error) {
          alert("Error: " + error);
        }
      })
    }
</script>

Model Function Code:

public IActionResult OnGetWriteLog(string msg)
{
    return new JsonResult(msg); 
}

Test Results: