title: jQuery unobtrusive validation - can't add in simple custom client validation rule
body: <p>I'm trying to add a single, simple client-only validation rule while using jQuery unobtrusive. My validation function is never called, the alert never fires. What am I doing wrong? I've stripped this down from a much more complex MVC application.</p>
  
  <pre><code>&lt;html&gt;
  &lt;head&gt;
  &lt;script src="//ajax.aspnetcdn.com/ajax/jQuery/jquery-2.1.3.min.js"&gt;&lt;/script&gt;
  &lt;script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.13.1/jquery.validate.js"&gt;&lt;/script&gt;
  &lt;script src="//ajax.aspnetcdn.com/ajax/mvc/5.2.3/jquery.validate.unobtrusive.js"&gt;&lt;/script&gt;
  &lt;script&gt;
      jQuery.validator.addMethod("mysplit", function () {
          alert("in validator");
          return false;
      }, "Barf");
      result = jQuery.validator.unobtrusive.adapters.addBool("mysplit");
  &lt;/script&gt;
  &lt;/head&gt;
  &lt;body&gt;
  &lt;form method="post"&gt;
      &lt;input type="text" data-val="True", data-val-mysplit="error msg" /&gt;
      &lt;input type="submit" /&gt;
  &lt;/form&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>Not sure if this matters for a simple .htm file but in my web.config, everything looks correct:</p>
  
  <pre><code>&lt;add key="ClientValidationEnabled" value="true" /&gt;
  &lt;add key="UnobtrusiveJavaScriptEnabled" value="true" /&gt;
  &lt;add key="ValidationSettings:UnobtrusiveValidationMode" value="none" /&gt;
  </code></pre>