private_biodata.module

<?php
/**
 * @file
 * The main functionality for the module.
 */
require_once('includes/TripalFields/private_biodata.fields.inc');

/**
 * Implements hook_permission().
 */
function private_biodata_permission() {
   $permissions = [];

   // Add 'View Private' permissions for each content type.
   $bundles = tripal_get_content_types();
   foreach ($bundles as $bundle) {
     $permissions['view private ' . $bundle->name] = [
       'title' => t('%label: View Private Content', ['%label' => $bundle->label]),
       'description' => t('Allow the user to view private %label content. Content is indicated to be private using the "Private Tripal Content" field.', ['%label' => $bundle->label]),
     ];
   }

   return $permissions;
 }

/**
 * Implements hook_entity_info_alter().
 */
function private_biodata_entity_info_alter(&$entity_info) {

  // We need to override the original access callback
  // in order to allow our module to revoke access.
  // @see tripal/includes/tripal_entity.inc::tripal_entity_access line 488
  // @code (excerpt from the above file)
  // $results = module_invoke_all($entity_type . '_access', $entity, $op, $account);
  // if (in_array(TRUE, $results)) {
  //   return TRUE;
  // }
  // @endcode
  $entity_info['TripalEntity']['access callback'] = 'private_biodata_access';
}

/**
 * Implements hook_menu_alter().
 */
function private_biodata_menu_alter(&$items) {

  // We also need to alter the menu to ensure it uses our new callback.
  $items['bio_data/%']['access callback'] = 'private_biodata_access';
  $items['bio_data/%/view']['access callback'] = 'private_biodata_access';
}

/**
 * Checks access permissions for a given entity.
 *
 * This function is set for TripalEntity access checking in the
 * tripal_entity_info() under the 'access callback' element.
 *
 * @param $op
 *   The operation. One of: create, view, edit, delete.
 * @param $entity
 *   The entity to check access for.
 * @param $account
 *   The user account.
 * @param $entity_type
 *   The type of entity (will always be TripalEntity).
 */
function private_biodata_access($op, $entity = NULL, $account = NULL, $entity_type = NULL) {
  global $user;
  $cache = &drupal_static(__FUNCTION__, NULL);

  if (!isset($account)) {
    $account = $user;
  }

  if (is_object($entity) && is_a($entity, 'TripalEntity')) {
    $bundle_name = $entity->bundle;
    $entity_id = $entity->id;
  }
  elseif (is_numeric($entity)) {
    $entity_id = $entity;
    if (!isset($cache)) {
      $cache = cache_get("tripal_entity_access_cache");
      if (isset($cache->data)) {
        $cache = $cache->data;
      }
    }

    if (empty($cache)) {
      $cache = [];
    }

    if (isset($cache[$entity])) {
      $bundle_name = $cache[$entity];
    }
    else {
      $sql = 'SELECT {bundle} FROM tripal_entity WHERE id = :id';
      $bundle_name = db_query($sql, [':id' => $entity])->fetchField();
      $cache[$entity] = $bundle_name;
      cache_set("tripal_entity_access_cache", $cache);
    }
  }
  else {
    return FALSE;
  }

  if (!$entity_type) {
    if (is_object($entity)) {
      $entity_type = $entity->type;
    }
    else {
      $entity_type = 'TripalEntity';
    }
  }

  // --- What's different from Tripal Core -------------------------------
  // The bit above is also done in Tripal Core but we need the variables
  // so we had to duplicate it. The code will not be run 2X because we can
  // pass the already determined values into tripal_entity_access below.
  // We only care about viewing.
  if ($op == 'view') {

    // We also only care if this entity is private...
    $is_private = db_query('SELECT private FROM {private_biodata}
      WHERE entity_id=:id',
      [':id' => $entity_id])->fetchField();

     // If we have it marked as private...
    if ($is_private) {
      // then return the custom permission provided by this module.
      return user_access('view private ' . $bundle_name, $account);
    }
  }

  // If we reach here then this is not a situation this module cares about.
  // as such, defer to Tripal Core.
  return tripal_entity_access($op, $entity, $account, $entity_type);
  // ---------------------------------------------------------------------
}