title: How to do complex validation in laravel across multiple fields?
body: <p>I have a form that requires you to enter an address. The fields requested are:</p>
  
  <ol>
  <li>street address</li>
  <li>suburb</li>
  <li>postal code</li>
  </ol>
  
  <p>Individual validation on these fields are easy. You can simply use "required" and "min" etc to make sure that it's filled in. But I need a third validation option that does the following:</p>
  
  <ol>
  <li>build a string consisting of these three parameters</li>
  <li>pass these fields to a service called "addressValidator" </li>
  <li>confirm if the address is "overall" valid</li>
  <li>place the error message only under one of the fields (street address) if they all fail</li>
  </ol>
  
  <p>How would you create such a validator on a form?</p>