title: yajra/laravel-datatables filterColumn doesnt work
body: <p>Page loading correctly and every things work fine while bringing datas. Now I want to filter them but FilterColumn() method doesnt even work. When I tried filter() method it's working but then I won't get $keywords variable. I am missing something while querying leads ?</p>
  <pre><code>if (request()-&gt;ajax()) {
          $leads = Lead::with('country','agent','detail')-&gt;orderBy('id','DESC');
  
          $leads-&gt;where(function($q) use ($user){
              if ($user-&gt;hasRole('agent')  &amp;&amp; !$user-&gt;hasRole('admin') &amp;&amp; !$user-&gt;hasRole('lead')){  //agent isem
                  $q-&gt;where('agent_id',$user-&gt;id)
                  -&gt;orWhere('agent_id',null);
              }
          });
  
          return DataTables::of($leads)-&gt;
          addColumn('edit_button', function ($lead) {
              $link  = route('leads.edit',$lead-&gt;id);
              return '&lt;a href=&quot;'.$link.'&quot; class=&quot;btn btn-info btn-sm ad-click-event&quot;&gt; Edit &lt;/a&gt;';
          })-&gt;
          filterColumn('edit_button', function ($query, $keyword) {
              dd($keyword);
              return $query-&gt;whereHas('patient', function ($query) use ($keyword) {
                  $query-&gt;whereRaw(&quot;CONCAT( name,  ' ', surname ) like ?&quot;, [&quot;%$keyword%&quot;]);
              });
          })-&gt;rawColumns(['edit_button','phone','detail.conversion_notes'])-&gt;
  
          toJson();
  }
   $tableColumn = [
          ['data' =&gt; 'edit_button', 'name' =&gt; 'edit_button', 'title' =&gt; 'Edit', 'searchable' =&gt; false],
          ['data' =&gt; 'full_name', 'name' =&gt; 'full_name', 'title' =&gt; 'Full Name'],
          ['data' =&gt; 'phone', 'name' =&gt; 'phone', 'title' =&gt; 'Phone'],
          ['data' =&gt; 'email', 'name' =&gt; 'email', 'title' =&gt; 'Email'],
          ['data' =&gt; 'country.name', 'name' =&gt; 'country.name', 'title' =&gt; 'Country'],
  
          ['data' =&gt; 'agent.name', 'name' =&gt; 'agent.name', 'title' =&gt; 'Agent'],
          ['data' =&gt; 'treatment', 'name' =&gt; 'treatment', 'title' =&gt; 'Treatment'],
          ['data' =&gt; 'find_us', 'name' =&gt; 'find_us', 'title' =&gt; 'Find Us'],
          ['data' =&gt; 'form_type', 'name' =&gt; 'form_type', 'title' =&gt; 'Form','visible' =&gt; false],
          ['data' =&gt; 'social_account', 'name' =&gt; 'social_account', 'title' =&gt; 'Sosyal Medya'],
          ['data' =&gt; 'created_at', 'name' =&gt; 'created_at', 'title' =&gt; 'Created At'],
          ['data' =&gt; 'detail.conversion_notes', 'name' =&gt; 'detail.conversion_notes', 'title' =&gt; 'Primary Notes'],
      ];
  
  
      $html = $builder-&gt;columns($tableColumn)-&gt;parameters([
          &quot;pageLength&quot; =&gt; 25,
          &quot;lengthMenu&quot; =&gt; [[10, 25, 50, 100, -1], [10, 25, 50, 100, &quot;All&quot;]],
          'dom' =&gt; 'Bfrtip',
          'columnDefs' =&gt; [
              ['width' =&gt; '2%', 'targets' =&gt; 0],
              ['width' =&gt; '7%', 'targets' =&gt; 1],
          'buttons' =&gt; [
              'pageLength',
              [
                  'extend' =&gt; 'colvis',
                  'collectionLayout' =&gt; 'fixed two-column',
                  'columns' =&gt; ':not(.noVis)'
              ]
          ]
      ]);
  </code></pre>