class.queue.php

    function filter($text, $row) {
        $link = $this->getLink($row);
        return sprintf('<a class="preview" data-preview="#tickets/%d/preview" href="%s">%s</a>',
            $row['ticket_id'], $link, $text);
    }
}
QueueColumnFilter::register('TicketLinkWithPreviewFilter');

class QueueColDataConfigForm
extends AbstractForm {
function buildFields() {
    return array(
        'primary' => new DataSourceField(array(
            'label' => __('Primary Data Source'),
            'required' => true,
            'configuration' => array(
                'root' => 'Ticket',
            ),
            'layout' => new GridFluidCell(6),
        )),
        'secondary' => new DataSourceField(array(
            'label' => __('Secondary Data Source'),
            'configuration' => array(
                'root' => 'Ticket',
            ),
            'layout' => new GridFluidCell(6),
        )),
            'heading' => new TextboxField(array(
                'label' => __('Heading'),
                'required' => true,
                'layout' => new GridFluidCell(3),
            )),
            'filter' => new ChoiceField(array(
                'label' => __('Filter'),
                'required' => false,
                'choices' => QueueColumnFilter::getFilters(),
                'layout' => new GridFluidCell(3),
            )),
            'width' => new TextboxField(array(
                'label' => __('Width'),
                'default' => 75,
                'configuration' => array(
                    'validator' => 'number',
                ),
                'layout' => new GridFluidCell(3),
            )),
            'truncate' => new ChoiceField(array(
                'label' => __('Text Overflow'),
                'choices' => array(
                    'wrap' => __("Wrap Lines"),
                    'ellipsis' => __("Add Ellipsis"),
                    'clip' => __("Clip Text"),
                ),
                'default' => 'wrap',
                'layout' => new GridFluidCell(3),
            )),
        );
    }
}