taxonomy_term_depth_access.inc

<?php
/**
 * @file
 * Plugin to provide access control based upon taxonomy term depth.
 */
class TaxonomyTermDepthLayoutAccess extends LayoutAccess {
  /**
   * Constructor for a Layout access rule.
   */
  public function __construct($plugin_name, array $data = array()) {
    parent::__construct($plugin_name, $data);
    $this->settings += array(
      'depth' => array()
    );
  }

  /**
   * {@inheritdoc}
   */
  public function form(&$form, &$form_state) {
    parent::form($form, $form_state);

    $form['depth'] = array(
      '#type' => 'number',
      '#title' => t('Depth'),
      '#description' => t('Depth is the level of nesting for a taxonomy term. See example below.'),
      '#default_value' => $this->settings['depth'],
    );

    $code  = '<code>';
    $code .= t('State (1st level, <strong>depth 1</strong>)') . '<br />';
    $code .= '- ' . t('City (2nd level, <strong>depth 2</strong>)') . '<br />';
    $code .= '&nbsp; - ' . t('Neighborhood (3rd level, <strong>depth 3</strong>)');
    $code .= '</code>';

    $form['depth_example'] = array(
      '#type' => 'markup',
      '#markup' => $code,
    );
  }

  /**
   * {@inheritdoc}
   */
  public function formSubmit($form, &$form_state) {
    parent::formSubmit($form, $form_state);
    $this->settings['depth'] = $form_state['values']['depth'];
  }

  /**
   * {@inheritdoc}
   */
  public function summary() {
    if (isset($this->settings['depth'])) {
      return t('Taxonomy term depth: @depth', array('@depth' => $this->settings['depth']));
    }

    return '';
  }

  /**
   * {@inheritdoc}
   */
  public function checkAccess() {
    if (!isset($this->contexts['taxonomy_term']->data)) {
      return FALSE;
    };

    $tid = $this->contexts['taxonomy_term']->data->tid;
    $depth = $this->getTermDepth($tid);

    if ($depth == $this->settings['depth']) {
      return TRUE;
    }

    return FALSE;
  }

  /**
   * Gets the depth of a term.
   *
   * @param $tid
   *   The taxonomy term ID
   *
   * @return int
   *   An integer representing how many levels deep your term is nested.
   */
  protected function getTermDepth($tid) {
    $parent = db_query("SELECT parent FROM {taxonomy_term_hierarchy} WHERE tid = :tid", array(':tid' => $tid))->fetchField();
    if ($parent == 0) {
      return 1;
    }
    else {
      return 1 + $this->getTermDepth($parent);
    }
  }
}