views_handler_filter_fields_compare.inc

<?php


/**
 * @file
 * Definition of views_handler_filter_fields_compare.
 */

/**
 * A handler to filter a view using fields comparison.
 *
 * @ingroup views_filter_handlers
 */
class views_handler_filter_fields_compare extends views_handler_filter {
    
    /**
     * {@inheritdoc}
     */
    public function can_expose() {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function option_definition() {
        $options = parent::option_definition();
        $options['left_field'] = $options['right_field'] = array(
            'default' => '',
        );
        return $options;
    }
    
    /**
     * Provide a list of all operators.
     */
    public function fields_operator_options() {
        return array(
            '<' => t('Is less than'),
            '<=' => t('Is less than or equal to'),
            '=' => t('Is equal to'),
            '<>' => t('Is not equal to'),
            '>=' => t('Is greater than or equal to'),
            '>' => t('Is greater than'),
        );
    }
    
    /**
     * Provide a list of available fields.
     */
    public function field_options() {
        $options = array();
        $field_handlers = $this->view->display_handler
            ->get_handlers('field');
        foreach ($field_handlers as $field => $handler) {
            if ($handler->table != 'views') {
                $options[$field] = $handler->ui_name();
            }
        }
        return $options;
    }
    
    /**
     * {@inheritdoc}
     */
    public function options_form(&$form, &$form_state) {
        parent::options_form($form, $form_state);
        $field_options = $this->field_options();
        $form['left_field'] = array(
            '#type' => 'select',
            '#title' => t('Left field'),
            '#default_value' => $this->options['left_field'],
            '#options' => $field_options,
            '#weight' => -3,
        );
        $form['operator'] = array(
            '#type' => 'select',
            '#title' => t('Operator'),
            '#default_value' => $this->options['operator'],
            '#options' => $this->fields_operator_options(),
            '#weight' => -2,
        );
        $form['right_field'] = array(
            '#type' => 'select',
            '#title' => t('Right field'),
            '#default_value' => $this->options['right_field'],
            '#options' => $field_options,
            '#weight' => -1,
        );
    }
    
    /**
     * {@inheritdoc}
     */
    public function query() {
        // Build extra condition from existing fields (from existing joins).
        $left = $this->options['left_field'];
        $right = $this->options['right_field'];
        // Get all existing field handlers.
        $field_handlers = $this->view->display_handler
            ->get_handlers('field');
        // Make sure the selected fields still exist.
        if (!isset($field_handlers[$left], $field_handlers[$right])) {
            return;
        }
        // Get the left table and field.
        $left_handler = $field_handlers[$left];
        $left_handler->set_relationship();
        $left_table_alias = $this->query
            ->ensure_table($left_handler->table, $left_handler->relationship);
        // Get the left table and field.
        $right_handler = $field_handlers[$right];
        $right_handler->set_relationship();
        $right_table_alias = $this->query
            ->ensure_table($right_handler->table, $right_handler->relationship);
        // Build piece of SQL.
        $snippet = $left_table_alias . '.' . $left_handler->real_field . ' ' . $this->options['operator'] . ' ' . $right_table_alias . '.' . $right_handler->real_field;
        $this->query
            ->add_where_expression($this->options['group'], $snippet);
    }
    
    /**
     * {@inheritdoc}
     */
    public function admin_summary() {
        return check_plain($this->options['left_field'] . ' ' . $this->options['operator'] . ' ' . $this->options['right_field']);
    }

}