title: How to validate so that at least 1 field is required from a group, when the 2nd field has two required fields
body: <p>Apologies for the confusing question title. I understand how to use the required_from_group method to ensure that at least 1 field is filled in from a group. I do it like this:</p>
  
  <p>Example HTML</p>
  
  <pre><code>&lt;form&gt;
    &lt;select name="ProductID" id="ProductID" class="js-product"&gt;
      &lt;option value="1"&gt;Bounty&lt;/option&gt;
      &lt;option value="2"&gt;Snickers&lt;/option&gt;
    &lt;/select&gt;
    &lt;input type="text" name="ProductName" id="ProductName" class="js-product" /&gt;
    &lt;select name="Country" id="Country"&gt;
      &lt;option value="US"&gt;United States&lt;/option&gt;
      &lt;option value="CA"&gt;Canada&lt;/option&gt;
      &lt;option value="UK"&gt;United Kingdom&lt;/option&gt;
    &lt;/select&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>Here is example JQuery Validate to ensure the user selects a <code>ProductID</code> from the select dropdown, or they type in the product name in the <code>ProductName</code> textfield. It does this because the class of <code>.js-product</code> is applied to those two inputs to define it as a group.</p>
  
  <pre><code>$('form').validate({
  ...
  rules: {
          ProductID: {
                  require_from_group: [1, ".js-product"]
           },
          ProductName: {
                  require_from_group: [1, ".js-product"]
           }
  });
  </code></pre>
  
  <p>The issue I have is that if the user types in a Product Name, he also needs to specify the Country for that product. So I actually need the user to:</p>
  
  <ol>
  <li>Fill in either the ProductID by selecting a product from the list OR type in the product name</li>
  <li>If the User types in a product name manually, then they MUST also choose a Country from the dropdown where that product originates from</li>
  </ol>
  
  <p>How do I ensure that <code>ProductName</code> and <code>'Country'</code> are in a group that is only required when the <code>ProductID</code>  drop down is left NULL?</p>
  
  <p>One possible idea I thought of was to make the <code>Country</code> dropdown required on a <code>blur</code> event taking place in the <code>ProductName</code> field.  Is there a better way?</p>