List of permissions for Drupal8 routing file - symfony

Question

I'm working on custom Drupal8 module. My module uses this routing file:
kalvis.routing.yml
kalvis.content:
path: '/kalvis/{from}/{to}'
defaults:
_controller: '\Drupal\kalvis\Controller\kalvisController::content'
_title: ''
requirements:
_permission: 'access content'
What does _permission part stand for and where can I find a list of all possible values for this parameter?(in tut's I've watched were used only access content and access administrative content but I suppose there is a lot more of them)
PS: I'm using Drupal 8 beta 10 installed on WAMP

Answer 1

If you want to see a list of all permission, the code below should work. work. If you are coding your own module you can define your own permissions and test if a user has a role with that permission.
function my_module_page_attachments_alter(array &$attachments) {
$perms = array_keys(\Drupal::service('user.permissions')->getPermissions());
}

Answer 2

To answer the question what is the _permission part of the routing structure. Here is a quote from the drupal docs about what it does.
_permission: A permission string (e.g., _permission: 'access content'). You can specify multiple permissions by separating them with ',' (comma) (e.g., _permission: 'access content,access user profiles') for AND logic or '+' (plus) for OR logic (e.g., _permission: 'access content+access user profiles' means a visitor needs either the access content permission or the access user profiles permission to view the page. Having both is fine, too.). Module-specific permission strings can be defined in my_module_name.permissions.yml. See hook_permission() replaced with permissions defined in a my_module_name.permissions.yml file for details.
source: https://www.drupal.org/docs/drupal-apis/routing-system/structure-of-routes
To put it simply this restricts access to this route by only allowing users with the specified permission(s) to access it. To use it you need to know the system name of the permission(s) you want to use to restrict access. Then you just place then as a string behind this paramerter. Like in the quote above. You can choose to use multiple permissions by separating them with , for AND logic or + for OR logic. Permissions system names are allowed to have spaces in them and frequently do.
I don't think there is any way to directly see it in ui if you are talking about the system names of the permissions. You can ofcource see all permissions on www.site.com/admin/people/permissions. If you are in a hurry and/or looking for a specific permission you can always look through the module.permissions.yml file of the module this permission is defined in.
If you do want to see all permissions you can make your own list of all the system names.
You can use the PermissionHandler service from the core module.
This does the following gets all yaml's and creates a list.
You would call this by calling Drupal::service('user.permissions')->getPermissions() (https://api.drupal.org/api/drupal/core%21modules%21user%21src%21PermissionHandler.php/function/PermissionHandler%3A%3AgetPermissions/8.2.x)
You can use or try to write similar code to the functionality of the user_role_permissions function from the user.module file in drupal core. It looks like this:
function user_role_permissions(array $roles) {
if (defined('MAINTENANCE_MODE') && MAINTENANCE_MODE == 'update') {
return _user_role_permissions_update($roles);
}
$entities = Role::loadMultiple($roles);
$role_permissions = array();
foreach ($roles as $rid) {
$role_permissions[$rid] = isset($entities[$rid]) ? $entities[$rid]
->getPermissions() : array();
}
return $role_permissions;
}
This code as you can see just loads all the role entities with loadMultiple (although technically you should use the entitytypemanager to load the entities whenever possible like $entities = \Drupal::entityTypeManager()->getStorage($entity_type)->loadMultiple([1, 2, 3]); for more information see the drupal entity api (https://www.drupal.org/docs/drupal-apis/entity-api/working-with-the-entity-api)).
After loading all the roles it makes a list of all permissions.
Source information below. This should stay up to date because drupal keeps their documentation versioned. But because comments suggested it I figured I might as well write it out to save you some clicks.
Original drupal documentation.
https://api.drupal.org/api/drupal/core!modules!user!user.module/function/user_role_permissions/8.2.x
Hope this helps! :)

Answer 3

You can confirm in the page '/admin/people/permissions'.

Answer 4

A quick and dirty way to see them is to create a View with a Page display. Then in the 'Access' section, ensure 'Permission' is selected and open up the options as if you were going to choose a different permission.
You can now inspect the HTML of the <select> element, the Ids of each option is the correct name for each permission: