farm_access.module in farmOS 7

Farm Access module.
File

modules/farm/farm_access/farm_access.module
View source
<?php

/**
 * @file
 * Farm Access module.
 */

// Define the default allowed origins.
define('FARM_ACCESS_DEFAULT_ALLOWED_ORIGINS', "https://v1.farmos.app\nhttps://farmos.app");

/**
 * Implements hook_init().
 */
function farm_access_init() {

  // Add CORS headers to allow API access from approved origins.
  farm_access_add_cors_headers();
}

/**
 * Add CORS headers.
 */
function farm_access_add_cors_headers() {

  // Load the list of allowed origins.
  $allowed_origins = explode("\n", variable_get('farm_access_allow_origin', FARM_ACCESS_DEFAULT_ALLOWED_ORIGINS));

  // Trim whitespace from each item.
  foreach ($allowed_origins as &$value) {
    $value = trim($value);
  }

  // Add "app://localhost" to the list of allowed origins, so that requests from
  // Field Kit on iOS native (WKWebView) are accepted.
  $allowed_origins[] = 'app://localhost';

  // Get the request headers.
  $headers = getallheaders();

  // If the "Origin" header is set, check to see if it is in the allowed list.
  if (!empty($headers['Origin'])) {
    if (in_array($headers['Origin'], $allowed_origins)) {

      // Add headers to allow CORS requests.
      drupal_add_http_header('Access-Control-Allow-Origin', $headers['Origin']);
      drupal_add_http_header('Access-Control-Allow-Credentials', 'true');
      drupal_add_http_header('Access-Control-Allow-Headers', 'Content-Type,Authorization,X-CSRF-Token');
      drupal_add_http_header('Access-Control-Allow-Methods', 'GET,POST,PUT,DELETE,HEAD,OPTIONS');

      // Add a "Vary: Origin" header to indicate to clients that server
      // responses will differ based on the value of the "Origin" request
      // header.
      // See https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
      drupal_add_http_header('Vary', 'Origin');
    }
  }
}

/**
 * If getallheaders() is not available, implement it ourselves.
 *
 * This is necessary in PHP CLI and Nginx contexts.
 * See https://github.com/farmOS/farmOS/issues/271#issuecomment-663543706
 *
 * Code is taken from http://php.net/manual/en/function.getallheaders.php
 */
if (!function_exists('getallheaders')) {
  function getallheaders() {
    foreach ($_SERVER as $name => $value) {
      if (substr($name, 0, 5) == 'HTTP_') {
        $headers[str_replace(' ', '-', ucwords(strtolower(str_replace('_', ' ', substr($name, 5)))))] = $value;
      }
    }
    return $headers;
  }
}

/**
 * Implements hook_hook_info().
 */
function farm_access_hook_info() {
  $hooks['farm_access_roles'] = array(
    'group' => 'farm_access',
  );
  $hooks['farm_access_perms'] = array(
    'group' => 'farm_access',
  );
  $hooks['farm_access_perms_alter'] = array(
    'group' => 'farm_access',
  );
  return $hooks;
}

/**
 * Implements hook_permission().
 */
function farm_access_permission() {
  $perms = array(
    'administer farm_access module' => array(
      'title' => t('Administer farm access module'),
    ),
  );
  return $perms;
}

/**
 * Implements hook_farm_access_perms().
 */
function farm_access_farm_access_perms($role) {
  $perms = array();

  // Load the list of farm roles.
  $roles = farm_access_roles();

  // If this role has 'config' access, grant access to farm_access configuration.
  if (!empty($roles[$role]['access']['config'])) {
    $perms[] = 'administer farm_access module';
  }
  return $perms;
}

/**
 * Implements hook_menu().
 */
function farm_access_menu() {

  // Access configuration form.
  $items['admin/config/farm/access'] = array(
    'title' => 'Access',
    'description' => 'Access configuration settings.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'farm_access_settings_form',
    ),
    'access arguments' => array(
      'administer farm_access module',
    ),
  );
  return $items;
}

/**
 * Implements hook_module_implements_alter().
 */
function farm_access_module_implements_alter(&$implementations, $hook) {

  // Ensure that our hook_menu_alter() runs last, so that we can alter paths
  // provided by Views (which are defined in views_menu_alter()).
  if ($hook == 'menu_alter') {
    $module = 'farm_access';
    $group = $implementations[$module];
    unset($implementations[$module]);
    $implementations[$module] = $group;
  }
}

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

  // Define a list of paths that will need to respond to OPTIONS requests
  // (eg: from Field Kit). Override their access callback to return TRUE for
  // OPTIONS requests, otherwise delegate to the original access callback.
  $paths = array(
    'farm/areas/geojson',
  );
  foreach ($paths as $path) {
    if (array_key_exists($path, $items)) {
      array_unshift($items[$path]['access arguments'], $items[$path]['access callback']);
      $items[$path]['access callback'] = 'farm_access_options_access_callback';
    }
  }
}

/**
 * Access callback for paths that need to respond to OPTIONS requests. This will
 * receive the original access callback as the first argument, and any other
 * arguments after that.
 *
 * @param $callback
 *   The access callback to delegate to for non-OPTIONS requests.
 *
 * @return bool
 */
function farm_access_options_access_callback($callback) {

  // If this is an OPTIONS request, allow access.
  if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    return TRUE;
  }

  // Otherwise, delegate to the original access callback.
  $args = func_get_args();
  array_shift($args);
  return call_user_func_array($callback, $args);
}

/**
 * Access settings form.
 */
function farm_access_settings_form($form, &$form_state) {

  // Metric or US/Imperial.
  $form['farm_access_allow_origin'] = array(
    '#type' => 'textarea',
    '#title' => t('Access-Control-Allow-Origin'),
    '#description' => t('This will be put in the Access-Control-Allow-Origin header, which is necessary for third-party client-side applications to access farmOS data via the API. The default allows access from the farmOS Field Kit application. Multiple origins can be specified (one per line) and they will be matched automatically.'),
    '#default_value' => variable_get('farm_access_allow_origin', FARM_ACCESS_DEFAULT_ALLOWED_ORIGINS),
  );

  // Return it as a system settings form.
  return system_settings_form($form);
}

/**
 * Load a list of farm roles.
 *
 * @return array
 *   Returns an array of farm role names.
 */
function farm_access_roles() {

  // Invoke hook_farm_access_roles() to get a list of roles.
  return module_invoke_all('farm_access_roles');
}

/**
 * Create farm roles.
 */
function farm_access_roles_create() {

  // Get a list of farm roles.
  $roles = farm_access_roles();

  // Iterate through the roles.
  foreach ($roles as $key => $info) {

    // If the name is blank, skip.
    if (empty($info['name'])) {
      continue;
    }

    // Load the role by name.
    $role = user_role_load_by_name($info['name']);

    // If the role doesn't exist, create it.
    if (empty($role)) {
      $role = new stdClass();
      $role->name = $info['name'];
      user_role_save($role);
    }
  }
}

/**
 * Synchronize all available farm permissions farm roles.
 */
function farm_access_sync_perms() {

  // Get a list of farm roles.
  $roles = farm_access_roles();

  // Iterate through the available roles.
  foreach ($roles as $name => $role) {

    // Compare current perms to available perms.
    $compare = farm_access_compare_perms($name);

    // Start with a blank array of changes.
    $changes = array();

    // Add perms.
    if (!empty($compare['add'])) {
      foreach ($compare['add'] as $perm) {
        $changes[$perm] = TRUE;
      }
    }

    // Remove perms.
    if (!empty($compare['remove'])) {
      foreach ($compare['remove'] as $perm) {
        $changes[$perm] = FALSE;
      }
    }

    // If there are changes to be made...
    if (!empty($changes)) {

      // Load the role.
      $role = user_role_load_by_name($role['name']);

      // If the role does not exist, bail.
      if (empty($role)) {
        return;
      }

      // Apply the changes.
      user_role_change_permissions($role->rid, $changes);
    }
  }
}

/**
 * Gets a list of all available farm permissions.
 *
 * @param string $role
 *    A farm role machine name to get current permissions for.
 *
 * @return array
 *   Returns an array of permission strings.
 */
function farm_access_available_perms($role) {

  // Load the permissions provided by this module on behalf of others.
  module_load_include('inc', 'farm_access', 'farm_access.modules');

  // Invoke hook_farm_access_perms() to allow modules to provide permissions.
  $perms = module_invoke_all('farm_access_perms', $role);

  // Unset any that don't exist.
  // This can be an issue with Taxonomies provided by Features.
  $permissions_modules = user_permission_get_modules();
  foreach ($perms as $key => $perm) {
    if (empty($permissions_modules[$perm])) {
      unset($perms[$key]);
    }
  }

  // Allow other modules to alter the permissions for this role.
  drupal_alter('farm_access_perms', $role, $perms);

  // Return them.
  return $perms;
}

/**
 * Gets a list of the permissions currently assigned to farm roles.
 *
 * @param string $role
 *   A farm role machine name to get current permissions for.
 *
 * @return array
 *   Returns an array of permission strings.
 */
function farm_access_current_perms($role) {

  // Load all farm roles.
  $roles = farm_access_roles();

  // If the role doesn't have a name, bail.
  if (empty($roles[$role]['name'])) {
    return array();
  }

  // Load the role.
  $role = user_role_load_by_name($roles[$role]['name']);

  // If the role does not exist, bail.
  if (empty($role)) {
    return array();
  }

  // Load the permissions that are currently assigned to the role.
  $perms = user_role_permissions(array(
    $role->rid => $role->name,
  ));

  // Return the permissions for this role, as an array of strings.
  return array_keys($perms[$role->rid]);
}

/**
 * Compares available permissions to actual permissions.
 *
 * @param string $role
 *   A farm role machine name to get current permissions for.
 *
 * @return array
 *   Returns an array with two sub-arrays:
 *     'add': a list of permission strings that should be added
 *     'remove': a list of permission strings that should be removed
 */
function farm_access_compare_perms($role) {

  // Get the available perms.
  $available_perms = farm_access_available_perms($role);

  // Get the currently applied perms.
  $current_perms = farm_access_current_perms($role);

  // Determine which perms should be added.
  $compare['add'] = array_diff($available_perms, $current_perms);

  // Determine which perms should be removed.
  $compare['remove'] = array_diff($current_perms, $available_perms);

  // Return the comparison.
  return $compare;
}

/**
 * Generate permission lists for farm entities.
 *
 * This is a helper function to make the task of generating permission lists
 * easier.
 *
 * @param array $types
 *   An array of entity types/bundles to generate permissions for. Example:
 *     $types = array(
 *       'taxonomy' => array(
 *         'farm_areas',
 *       ),
 *     );
 * @param array $ops
 *   An array of strings: 'create', 'view', 'edit', 'delete'
 *   Use this to specify exactly what kinds of permissions should be returned
 *   for each entity type. Only include the ones you want. If none are provided,
 *   all permissions will be returned. Example:
 *     $ops = array(
 *       'create',
 *       'view',
 *       'edit',
 *       'delete',
 *     );
 *
 * @return array
 *   Returns a list of permissions for the given entity type+bundle.
 */
function farm_access_entity_perms(array $types, $ops = array()) {

  // Start with an empty array.
  $perms = array();

  // If the operations array is empty, fill it in.
  if (empty($ops)) {
    $ops = array(
      'create',
      'view',
      'edit',
      'delete',
    );
  }

  // Iterate through the types.
  foreach ($types as $type => $bundles) {

    // Iterate through the bundles.
    foreach ($bundles as $bundle) {

      // Switch through available entity types.
      switch ($type) {

        // Farm Asset.
        case 'farm_asset':

          // Create.
          if (in_array('create', $ops)) {
            $perms[] = 'create ' . $bundle . ' farm assets';
          }

          // View.
          if (in_array('view', $ops)) {
            $perms[] = 'view any ' . $bundle . ' farm assets';
            $perms[] = 'view own ' . $bundle . ' farm assets';
          }

          // Edit.
          if (in_array('edit', $ops)) {
            $perms[] = 'edit any ' . $bundle . ' farm assets';
            $perms[] = 'edit own ' . $bundle . ' farm assets';
          }

          // Delete.
          if (in_array('delete', $ops)) {
            $perms[] = 'delete any ' . $bundle . ' farm assets';
            $perms[] = 'delete own ' . $bundle . ' farm assets';
          }
          break;

        // Farm Plan.
        case 'farm_plan':

          // Create.
          if (in_array('create', $ops)) {
            $perms[] = 'create ' . $bundle . ' farm plans';
          }

          // View.
          if (in_array('view', $ops)) {
            $perms[] = 'view any ' . $bundle . ' farm plans';
            $perms[] = 'view own ' . $bundle . ' farm plans';
          }

          // Edit.
          if (in_array('edit', $ops)) {
            $perms[] = 'edit any ' . $bundle . ' farm plans';
            $perms[] = 'edit own ' . $bundle . ' farm plans';
          }

          // Delete.
          if (in_array('delete', $ops)) {
            $perms[] = 'delete any ' . $bundle . ' farm plans';
            $perms[] = 'delete own ' . $bundle . ' farm plans';
          }
          break;

        // Log.
        case 'log':

          // Create.
          if (in_array('create', $ops)) {
            $perms[] = 'create ' . $bundle . ' log entities';
          }

          // View.
          if (in_array('view', $ops)) {
            $perms[] = 'view any ' . $bundle . ' log entities';
            $perms[] = 'view own ' . $bundle . ' log entities';
          }

          // Edit.
          if (in_array('edit', $ops)) {
            $perms[] = 'edit any ' . $bundle . ' log entities';
            $perms[] = 'edit own ' . $bundle . ' log entities';
          }

          // Delete.
          if (in_array('delete', $ops)) {
            $perms[] = 'delete any ' . $bundle . ' log entities';
            $perms[] = 'delete own ' . $bundle . ' log entities';
          }
          break;

        // Taxonomy term.
        case 'taxonomy_term':

          // Edit.
          if (in_array('edit', $ops)) {
            $perms[] = 'edit terms in ' . $bundle;
          }

          // Delete.
          if (in_array('delete', $ops)) {
            $perms[] = 'delete terms in ' . $bundle;
          }
          break;
      }
    }
  }

  // Return the permissions.
  return $perms;
}

/**
 * Generate permission lists for farm entity bundles for a given role.
 *
 * This is a helper function to make the task of generating permission lists
 * easier. It uses farm_access_entity_perms() above.
 *
 * @param $entity_type
 *   The entity type.
 * @param $role
 *   The farm access role that will be receiving the permissions.
 *
 * @return array
 *   Returns a list of permissions for the given entity type, bundles, and role.
 */
function farm_access_entity_bundles_role_perms($entity_type, $role) {
  $perms = array();

  // Get a list of bundles for this entity type.
  $bundles = array();
  $entity_type_info = entity_get_info($entity_type);
  if (!empty($entity_type_info['bundles'])) {
    foreach ($entity_type_info['bundles'] as $name => $bundle) {
      $bundles[] = $name;
    }
  }

  // Load the list of farm roles.
  $roles = farm_access_roles();

  // Grant access to view and edit entity type bundles.
  $access_ops = array(
    'view' => array(
      'view',
    ),
    'edit' => array(
      'create',
      'edit',
      'delete',
    ),
  );
  foreach ($access_ops as $access => $ops) {

    // If the role has access to these asset operations...
    if (!empty($roles[$role]['access'][$access])) {

      // Build a list of entity type bundles that they have access to. If 'all'
      // access is granted, add all permissions. Or, if specific bundles are
      // specified, add them individually.
      $access_types[$entity_type] = array();
      if ($roles[$role]['access'][$access] == 'all' || !empty($roles[$role]['access'][$access][$entity_type]) && $roles[$role]['access'][$access][$entity_type] == 'all') {
        foreach ($bundles as $type) {
          $access_types[$entity_type][] = $type;
        }
      }
      elseif (!empty($roles[$role]['access'][$access][$entity_type])) {
        foreach ($roles[$role]['access'][$access][$entity_type] as $bundle) {
          if (!empty($bundles[$bundle])) {
            $access_types[$entity_type][] = $bundle;
          }
        }
      }

      // Build a list of entity permissions for the assets and operations and
      // merge them into the permissions this function will return.
      $entity_perms = farm_access_entity_perms($access_types, $ops);
      $perms = array_merge($perms, $entity_perms);
    }
  }

  // Return the permissions.
  return $perms;
}

/**
 * Implements hook_modules_enabled().
 */
function farm_access_modules_enabled($modules) {

  // Create new roles.
  farm_access_roles_create();

  // Load a list of modules that implement hook_farm_access_perms() or
  // hook_farm_access_perms_alter().
  $perms_implementations = module_implements('farm_access_perms');
  $alter_implementations = module_implements('farm_access_perms_alter');

  // If one of the modules being enabled implements hook_farm_access_perms() or
  // hook_farm_access_perms_alter(), sync permissions.
  if (array_intersect($modules, $perms_implementations) || array_intersect($modules, $alter_implementations)) {
    farm_access_sync_perms();
  }
}

/**
 * Implements hook_form_alter().
 */
function farm_access_form_alter(&$form, &$form_state, $form_id) {

  // Add our submit function to the core permissions form if farm roles exist.
  if ($form_id == 'user_admin_permissions') {
    $roles = farm_access_roles();
    if (!empty($roles)) {
      $form['#submit'][] = 'farm_access_permissions_form_submit';
    }
  }
}

/**
 * Submit function for the core permissions form.
 */
function farm_access_permissions_form_submit($form, &$form_state) {

  // Create new roles.
  farm_access_roles_create();

  // Sync permissions.
  farm_access_sync_perms();

  // Tell the user that we are enforcing the permissions, so there's no
  // confusion.
  drupal_set_message(t('Farm access permissions were automatically assigned.'));
}

/**
 * Implements hook_flush_caches().
 */
function farm_access_flush_caches() {

  // Create new roles.
  farm_access_roles_create();

  // Sync permissions when the cache is cleared.
  farm_access_sync_perms();
}
Functions

Name	Description
farm_access_add_cors_headers	Add CORS headers.
farm_access_available_perms	Gets a list of all available farm permissions.
farm_access_compare_perms	Compares available permissions to actual permissions.
farm_access_current_perms	Gets a list of the permissions currently assigned to farm roles.
farm_access_entity_bundles_role_perms	Generate permission lists for farm entity bundles for a given role.
farm_access_entity_perms	Generate permission lists for farm entities.
farm_access_farm_access_perms	Implements hook_farm_access_perms().
farm_access_flush_caches	Implements hook_flush_caches().
farm_access_form_alter	Implements hook_form_alter().
farm_access_hook_info	Implements hook_hook_info().
farm_access_init	Implements hook_init().
farm_access_menu	Implements hook_menu().
farm_access_menu_alter	Implements hook_menu_alter().
farm_access_modules_enabled	Implements hook_modules_enabled().
farm_access_module_implements_alter	Implements hook_module_implements_alter().
farm_access_options_access_callback	Access callback for paths that need to respond to OPTIONS requests. This will receive the original access callback as the first argument, and any other arguments after that.
farm_access_permission	Implements hook_permission().
farm_access_permissions_form_submit	Submit function for the core permissions form.
farm_access_roles	Load a list of farm roles.
farm_access_roles_create	Create farm roles.
farm_access_settings_form	Access settings form.
farm_access_sync_perms	Synchronize all available farm permissions farm roles.
Constants

Name	Description
FARM_ACCESS_DEFAULT_ALLOWED_ORIGINS
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farm_access.module in farmOS 7

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