title: DevExpress GridView - Custom filter function for a cell/column
body: <p>How to define a custom filter-function for a column or cell? Just as an example, assume we have a text value and in the header there is a search input</p>
  <p><a href="https://i.stack.imgur.com/3emPd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3emPd.png" alt="enter image description here" /></a></p>
  <p>How to tell the gridview to call a function</p>
  <pre class="lang-js prettyprint-override"><code>class FooComponent {
      protected doSomeFilter (value: string, searchQuery: string) {
          if (someConditions(value, searchQuery)) {
              return true;
          }
          return false;
      }
  }
  </code></pre>
  <p>And I would expect to use it like this:</p>
  <pre class="lang-html prettyprint-override"><code>&lt;dxi-column
      dataField=&quot;myFooProperty&quot;
      [(customFilter)]='doSomeFilter'
  &gt;&lt;/dxi-column&gt;
  </code></pre>
  <p>But the GridView doesn't support <code>customFilter</code> method, and nothing similar. Do you know how to achieve such custom filtering in devexpress, <em>looks very simple but I'm struggling with this for hours</em>. Thank you in advance.</p>