title: Client side validation is not firing for RequiredIf
body: <p>I am using <em>ExpressiveAnnotations</em> by <a href="https://github.com/JaroslawWaliszko/ExpressiveAnnotations" rel="nofollow">JaroslawWaliszko</a>. It works fine when I check server side through <code>ModelState.IsValid</code>. But it is not showing client side validation message. I don't know what things are missing. I have added <em>jquery</em> file too. Here is property on which I have applied <code>RequiredIf</code>:</p>
  
  <pre><code>// When Role = Assistant Professor(which has id = 3), 
  // His/ Her head's Id should be selected as ParentID.
  
  [RequiredIf("RoleID == 3", ErrorMessage = "Select Head.")] 
  public Nullable&lt;int&gt; ParentID { get; set; }
  </code></pre>
  
  <p>Rendered HTML is as below:</p>
  
  <pre><code>&lt;select class="form-control ng-pristine ng-valid" 
          data-val="true" 
          data-val-number="The field ParentID must be a number." 
          data-val-requiredif="Select Head." 
          data-val-requiredif-allowempty="false" 
          data-val-requiredif-constsmap="{}" 
          data-val-requiredif-expression="RoleID == 3" 
          data-val-requiredif-fieldsmap="{"RoleID":"numeric"}" 
          id="ParentID" 
          name="ParentID" 
          ng-model="DTO.ParentID" 
          ng-options="obj.Value as obj.Text for obj in headList"&gt;
  
      &lt;option selected="selected" value="" class=""&gt;--select--&lt;/option&gt;
      &lt;option value="0"&gt;Mr. Kevin Thomas&lt;/option&gt;
      &lt;option value="1"&gt;Ms. Lisa Brown&lt;/option&gt;
      &lt;option value="2"&gt;Mr. Sail Kapoor&lt;/option&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>Things I have implemented:</p>
  
  <ol>
  <li>Installed package: <em>Install-Package ExpressiveAnnotations</em>,</li>
  <li><p>Added below code in <em>Global.asax</em></p>
  
  <pre><code>DataAnnotationsModelValidatorProvider.RegisterAdapter(
      typeof (RequiredIfAttribute), typeof (RequiredIfValidator));
  DataAnnotationsModelValidatorProvider.RegisterAdapter(
      typeof (AssertThatAttribute), typeof (AssertThatValidator));
  </code></pre></li>
  <li><p>Added <em>expressive.annotations.validate.js</em> in bundle below <em>jquery</em> validation files, and added bundle on specified page.</p></li>
  </ol>