title: if inside class attribute html
body: <p>
          Navigation</li></p>
  
  <pre><code>    &lt;li&gt;
        &lt;a href="&lt;?=base_url();?&gt;backend/Administrator"
          class="&lt;?php ($_SERVER['REQUEST_URI']) ? 'class="waves-effect active"' : 'class="waves-effect"'; ?&gt;"&gt;&lt;i class="zmdi zmdi-view-dashboard"&gt;&lt;/i&gt; &lt;span&gt; Home &lt;/span&gt; &lt;/a&gt;
      &lt;/li&gt;
  
      &lt;li&gt;
        &lt;a href="&lt;?=base_url();?&gt;backend/Item" class="waves-effect"&gt;&lt;i class="zmdi zmdi-view-list-alt"&gt;&lt;/i&gt; &lt;span&gt; Item Management &lt;/span&gt; &lt;/a&gt;
      &lt;/li&gt;
  
      &lt;li&gt;
        &lt;a href="&lt;?=base_url();?&gt;backend/Item/tag" class="waves-effect"&gt;&lt;i class="zmdi zmdi-collection-plus"&gt;&lt;/i&gt; &lt;span&gt; Category Management &lt;/span&gt; &lt;/a&gt;
      &lt;/li&gt;
  
      &lt;li&gt;
        &lt;a href="&lt;?=base_url();?&gt;backend/User" class="waves-effect"&gt;&lt;i class="zmdi zmdi-account-o"&gt;&lt;/i&gt; &lt;span&gt; User Management &lt;/span&gt; &lt;/a&gt;
      &lt;/li&gt;
  
      &lt;li&gt;
        &lt;a href="&lt;?=base_url();?&gt;backend/Transaksi" class="waves-effect"&gt;&lt;i class="fa fa-exchange"&gt;&lt;/i&gt; &lt;span&gt; Transactions &lt;/span&gt; &lt;/a&gt;
      &lt;/li&gt;
  
      &lt;li&gt;
        &lt;a href="&lt;?=base_url();?&gt;backend/Transaksi/report" class="waves-effect"&gt;&lt;i class="zmdi zmdi-comment-more"&gt;&lt;/i&gt; &lt;span&gt; Report &lt;/span&gt; &lt;/a&gt;
      &lt;/li&gt;
    &lt;/ul&gt;
  </code></pre>
  
  <p>I'm using if inside the class, but it's not working.
  <br>If the URL is active then use class <code>waves-effect active</code>. If inactive then use class <code>waves-effect</code>
  <br> Please help me with any solution.</p>