Method processQuery

/**
 * Method to process the query from form.
 *
 * @param   array   $conditions  The conditions from the form.
 * @param   string  $filters     The columns to filter.
 * @param   array   $defaults    The defaults value to set if condition is empty.
 *
 * @return  DatabaseQuery  The query object.
 *
 * @since   3.5
 */
protected function processQuery($conditions, $filters, $defaults)
{
    // Get the database object.
    $db = Factory::getDbo();
    // Get the query object
    $query = $db->getQuery(true);
    // Select fields
    $query->select($conditions['select']);
    // From selected table
    $query->from($conditions['from']);
    // Join over the groups
    if (!empty($conditions['join'])) {
        $query->join('LEFT', $conditions['join']);
    }
    // Where condition
    if (!empty($conditions['where'])) {
        $query->where($conditions['where']);
    }
    // Group by
    if (!empty($conditions['group'])) {
        $query->group($conditions['group']);
    }
    // Process the filters
    if (\is_array($filters)) {
        $html_filters = Factory::getApplication()->getUserStateFromRequest($this->context . '.filter', 'filter', array(), 'array');
        foreach ($filters as $k => $value) {
            if (!empty($html_filters[$value])) {
                $escape = $db->quote($db->escape($html_filters[$value]), false);
                $query->where("{$value} = {$escape}");
            } elseif (!empty($defaults[$value])) {
                $escape = $db->quote($db->escape($defaults[$value]), false);
                $query->where("{$value} = {$escape}");
            }
        }
    }
    // Add order to query
    if (!empty($conditions['order'])) {
        $query->order($conditions['order']);
    }
    return $query;
}