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ajaxasp.net-mvcasp.net-mvc-5unobtrusive-ajax

Unobtrusive AJAX error: "Uncaught ReferenceError: Sys is not defined"

Example code: In an MVC 5 project in Visual Studio, I have set up the following controller and views:

Controller

TestController.cs

public class TestController : BaseController
{
    public ActionResult Index()
    {
        return View("Index");
    }

    public PartialViewResult MyPartialView1()
    {
        return PartialView("PartialView1");
    }

    public PartialViewResult MyPartialView2()
    {
        return PartialView("PartialView2");
    }
}

Views

Index.cshtml

@{
    Layout = null;
}

<!DOCTYPE html>

<html>
<head>
    <script src="@Url.Content("~/Scripts/jquery-2.1.1.min.js")"></script>
    <script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.min.js")"></script>
</head>
<body>
    <h1>Testing Unobtrusive AJAX</h1>
    @Ajax.ActionLink("Partial 1", "MyPartialView1", "Test",
                new AjaxOptions() { UpdateTargetId = "contentShouldLoadHere", InsertionMode = InsertionMode.Replace })
    |
    @Ajax.ActionLink("Partial 2", "MyPartialView2", "Test",
                new AjaxOptions() { UpdateTargetId = "contentShouldLoadHere", InsertionMode = InsertionMode.Replace })
    <div id="contentShouldLoadHere">
         <p>This will get replaced.</p>
    </div>
</body>
</html>

PartialView1.cshtml

<h1>Test 1</h1>

PartialView2.cshtml

<h1>Test 2</h1>

Question

If I have understood correctly, clicking "Partial 1" should load the contents of "PartialView1" into the HTML element with an ID of "contentShouldLoadHere". Instead, clicking "Partial 1" causes a normal page load of the MyPartialView1 action (~/Test/MyPartialView1), and in the Chrome dev tools console I get the following JavaScript error:

Uncaught ReferenceError: Sys is undefined

Does anyone know why this is, and how I can fix it?

Notes - I have confirmed via Chrome Dev Tools that both scripts are being correctly loaded. - The HTML for the link generated by the @Ajax helper is:

<a href="/Test/MyPartialView1" onclick="Sys.Mvc.AsyncHyperlink.handleClick(this, new Sys.UI.DomEvent(event), { insertionMode: Sys.Mvc.InsertionMode.replace, updateTargetId: &#39;contentShouldLoadHere&#39; });">Partial 1</a>
Solution

  • The html your generating for the link is generated if unobtrusive javascript has been disabled. You can enable it in the view with

    @{HtmlHelper.UnobtrusiveJavaScriptEnabled = true;}

    or for the application (in web.config) with

    <configuration>
  <appSettings>
    <add key="UnobtrusiveJavaScriptEnabled" value="true"/>

    Your rendered html should then look like

    <a data-ajax="true" data-ajax-mode="replace" data-ajax-update="#contentShouldLoadHere" href="/Test/Partial1">Partial 1</a>

    and will work with the jquery.unobtrusive-ajax.js file