edit

Permissions Framework in CiviCRM

Introduction

CiviCRM has a number of permissions that are able to be set through the relevant permissions page of your Content Management System. These are the primary way CiviCRM controls what parts of the application users are able to see. For example, accessing the "Scheduled Reminders" screen in CiviCRM requires the permission of Administer CiviCRM at least. Permissions are also there to control access to various entities such as contacts. There are generally 2 permissions Access All Contacts and Edit All Contacts. Users which have those permissions will be able to see and possibly edit all contacts.

Key Permissions

As mentioned in the introduction there are some crucial permissions to get heads around

  • Administer CiviCRM - This is a very broad permission and generally speaking is designed to grant access to any administrative parts of CiviCRM
  • Edit All Contacts, View All Contacts - This grants access to all contacts within the database for editing purposes
  • Access All Customdata - This grants the user access to view and edit all the custom data in the system.
  • Access X - These permissions are for each core module e.g. CiviContribute CiviEvent. Where X will be the title of that module. These permissions grant access to those areas of CiviCRM. These permissions will only show up if the modules are enabled.

Implementing Permissions logic

When in an extension you create a page or form there will be an XML routing file that will be needed to register your path, within the XML document you can put in a key of access_arguments This allows developers to specify what should be the default permissions that are needed to access this url. It should be noted if you want to specify an "OR" condition e.g. "Administer CiviCRM or Access CiviEvent" you need to put it as xml<access_arguments>Administer CiviCRM;Access CiviEvent</access_arguments>. If you want to do an "AND" i.e. the user needs both permissions you should change the ; for a , in that example.

Permissions are also implemented within run functions of pages. Normally pages have permissions associated with the various forms and links. The main way this is done is by looking at the function getIdAndAction in CRM\Core\Page\Basic.php This determines what action e.g. Update, Browse, Delete etc and checks if the user has permission do to that Action.

Another function that does similar work but is more useful is CRM_Core_Permission::checkActionPermission. This generally gets used in BAO functions when preparing a list of links.

When you write code, you can look at CRM_Core_Permission::check to see if the user holds the required permissions.

API Permissions

Depending on how the API is called, it is either called with a check_permissions flag turned off or turned on. When it is turned off, it will run the API without checking if the user has the necessary permissions to perform the action needed. If you turn check_permissions on then there will be tests done. By default code in CLI tools e.g. drush or WP-cli or within core code or extension code that is done at run time, the default in CiviCRM APIv3 is that the check_permissions flag is turned off. If you call the CiviCRM API through the rest interface then by default the check_permissions flag will be turned on. The permissions needed to make various API calls are defined in CRM_Core_Permission::getEntityActionPermissions()

Extending and Implementing Permission Structure

In an extension, authors have a wide ability to implement the same permissions structure as in CiviCRM Core but also to extend in a number of ways.

Implementing Permissions in extensions

hook_civicrm_navigationMenu allows for extension providers to define new menu items and the associated permissions to that menu item. However this does not specifically grant access to the end point just decides whether the menu item or not is visible to the user based on the permissions of that user.

To implement access to a specific url that you are creating as part of your extension. Extension authors should create a MyExtension.xml file in MyExtension/xml/Menu/. This file should be structure like the core menu XML files and this will determine the permissions to actually access the page not just whether a user can see the menu item or not.

Extending Permissions

If you want to add a permission to the list in the CMS, you can implement hook_civicrm_permission. Here, you can specify new permissions that will then be available to select within the CMS permissions.

Altering API Permissions

If you want to alter the permissions the API uses during its permissions check, you can implement the hook_civicrm_alterAPIPermissions. Note that you should be very careful when altering any permissions because they may have unintended consequences.