title: Is it possible to add custom filterfunction with PrimeNG DataTable?
body: <p>Basicly all info is provided in the title.</p>
  
  <p>It seems to me that I am bound to the filterMatchModes that are available ( contains, in, equals, endsWith, startsWith). In my usecase my column field is an array, and no single value.</p>
  
  <p>My specified column looks like this:</p>
  
  <pre><code>&lt;p-column field="types" [filter]="true" header="{{'AIRPORTS.TYPES' | translate}}"&gt;
      &lt;template let-airport="rowData" pTemplate="body"&gt;
          &lt;span *ngFor="let type of airport.types; let isLast = last"&gt;
              {{('AIRPORTS.' + type) | translate}}{{isLast ? '' : ', '}}
          &lt;/span&gt;
      &lt;/template&gt;
      &lt;template pTemplate="filter" let-col&gt;
          &lt;p-dropdown [options]="choices"
                      [style]="{'width':'100%'}"
                      (onChange)="airportsDataTable.filter($event.value,col.field,col.filterMatchMode)"
                      styleClass="ui-column-filter"&gt;
          &lt;/p-dropdown&gt;
      &lt;/template&gt;
  &lt;/p-column&gt;
  </code></pre>