title: Restrict form submit if file size is greater unobstrusive validation
body: <p>I have to apply file size uplaod validation </p>
  
  <pre><code>&lt;input type="file" name="UserModel.Resume" id="UserModel.Resume" class="fileSize" data-val="true" data-val-required="The CV field is required." /&gt;
  </code></pre>
  
  <p>and i have a file size checking function, </p>
  
  <pre><code>$('.fileSize').bind('change', function () {
          var fileSize = this.files[0].size / 1024 / 1024;
          if (fileSize &gt; 3) {
              $(this).addClass("input-validation-error");
          } else {
              $(this).removeClass("input-validation-error");
          }
      });
  </code></pre>
  
  <p>Is it possible to validatie through a function like</p>
  
  <pre><code>data-val-function="SomeFunction()" //Some function which return true if valid else false
  </code></pre>
  
  <p>I want to restrict from submitting the form if file size is greater than 3 MB, any kind of help will be helpful. </p>