title: Yii2 trim everything on save
body: <p>Yii2 framework. The idea to create common behavior for common model:</p>
  
  <ul>
  <li>before Validate trims all fields in model.</li>
  <li><p>if it's array trim all values in array.</p>
  
  <ol>
  <li><p>I'm wondered why in Yii2 core doesn't exist such possibility. Or I'm wrong. Am I?</p></li>
  <li><p>What problems could I face if I trim all fields?</p></li>
  </ol></li>
  </ul>