title: Is it possible to use Custom Validator together with or inside Unique Validator in Yii2?
body: <p>I have to check a few attributes with a unique validator, and one of them (<code>fb</code>) is a decimal, where I would like to use a range.</p>
  
  <pre><code>public function rules() {
      return [
          [['fd', 'zg', 'af_id', 'ffw_id', 'wdr', 'kl', 'tw', 'hm', 'fb'], 'unique', 'skipOnEmpty' =&gt; false, 'skipOnError' =&gt; false, 'targetAttribute' =&gt; 
           ['fd', 'zg', 'af_id', 'ffw_id', 'wdr', 'kl', 'tw', 'hm', 'fb']]
  </code></pre>
  
  <p>So all these attributes should be identical when validating: 'fd', 'zg', 'af_id', 'ffw_id', 'wdr', 'kl', 'tw', 'hm'</p>
  
  <p>And <code>fb</code> should be between <code>fb</code> + 0.1 and <code>fb</code> - 0.1</p>
  
  <p>Could you please point me to the right direction?</p>