title: Validate one attribute of an object using json schema
body: <p>I'm currenty using tv4 (json-schema validator) to validate (client-side) an object with a json-schema, which worked pretty well.</p>
  
  <p>But when I'm changing one value of an attribute, I want that this value is the only one, which should be validated.</p>
  
  <p>For example I have a user:</p>
  
  <pre><code>var user = { Name: 'Username', Age: 20 };
  </code></pre>
  
  <p>And the schema: </p>
  
  <pre><code>{
      "title": "UserValidation",
      "type": "object",
      "properties": {
          "Name": {
              "minLength": 4
          },
          "Age": {
              "type": "int"
          }
      }
  }
  </code></pre>
  
  <p>And when I only change the name, I don't want to check, if the attribute "Age" is valid.</p>
  
  <p>Reason: When I have a big object (with sub-models etc.) it will validate all properties. And I don't know if it's gonna be a performance problem (some day...).</p>
  
  <ul>
  <li>Is this a possible case with schema-validation? </li>
  <li>Or are there better
  ways to validate objects?</li>
  </ul>
  
  <p>I'm using AngularJS btw.</p>
  
  <p>Best regards and thanks.</p>