In what order are permissions settings applied?

It is important to understand that Tiki uses several types of permissions:

• Global permissions: Each site visitor belongs to a Group (such as Anonymous or Registered). The permissions you assign to the group define the global site-wide permissions for that user.
• Category permissions: These permissions define the actions that users can take for objects in a specific content category.
• Object permissions: These permissions define the actions that user can take for an individual object.
• See also: Permission Enforcement Order
  
  Tip: The setup of permissions is much easier when you are still learning how to master them if you avoid the level of Category permissions, and you only use Global and Object permissions.

Permissions are inherited from from the top-down, but override from the bottom-up.

This image illustrates the relationship among Group, Category, and Object permissions.

Tiki's permissions model may look like complex... but is also very customizable.

 Permissions Example

Consider the following example for a company using Tiki:
You have the groups:

• Anonymous
• Employees
• Board of Directors

The Groups for ABC Company

Notice that some groups include other groups. For example, members of the Board of Directors group will include, in addition to their own permissions, the permissions from the Employees, Registered, and Anonymous groups.

You have the categories:

• Financial Information
• Press Releases

You want to give:

• Everyone permission to read most pages
• Employees permission to edit most wiki pages
• Board Members only, access to the company's financial information.

First, you need to define the global permissions for each group.

Defining the Global permissions for each group.

Anonymous

• To let the general public (that is, anonymous visitors) view wiki pages, assign tiki_p_view to Anonymous.

Employees

• The Employee group includes the Anonymous group (that is, everyone) and Registered group (that is, users who are logged in). Therefore, the Employee group inherits the tiki_p_view permission from these groups.
• To let employees edit pages, assign tiki_p_edit to Employees.

Board of Directors

• The Board of Directors group includes the Anonymous, Registered, and Employees groups. Therefore, the Board of Directors group inherits the tiki_p_view and tiki_p_edit permission from these groups.
  This group does not require any additional permissions.

Now that the Global permissions are set, you can adjust the permissions for each category. These settings will override the Global permissions. The Category permissions can be set for each category from the Settings > Categories (tiki-admin_categories.php) page.

Press Releases

Currently, Anonymous can view press releases, and Employees can edit them (as defined by the Global permissions). To allow only the Board of Directors to edit press releases, you must assign permissions to the category. This will override the default group (global) permissions:

• For the Press Releases category, remove tiki_p_edit from Employee. Now only the Board of Directors group can edit wiki pages in the category.
• Anonymous visitors (and all groups that inherit the Anonymous group's permissions) can still view the pages.

Defining the Category permissions for the Press Releases category.

Financial Information

Currently, Anonymous can view Financial Information, and Employees can edit them. But we want only the Board of Directors to have access (both view and edit) to these pages. You'll need to make the same adjustments to the Financial Information category's permissions:

• Remove tiki_p_edit from Employee. Now only the Board of Directors group can edit wiki pages in the category.
• Remove tiki_p_view from Employee, Registered, and Anonymous. Now only the Board of Directors can see the pages.

But what if you want one item in the Financial Information category, to be visible to the public? You can override all other permissions, by assigning specific permissions to the object itself. For example, the ABC Company may have a public disclosure form, issued by the government, that it needs to make public (but that only the government can change or update):

• For the individual item, remove tiki_p_edit from the Employee and Board of Directors group. Since this form is issued by the government, no one should be able to change it.
• Anonymous visitors (and all groups that inherit the Anonymous group's permissions) can still view the pages.

Assigning object-specific permissions to the PublicDisclosure page.

Object Permissions can be tricky.

For example using version 10, if you wanted to hide one wiki page made by admin from the Anonymous group you would select the page's permissions (from the admin menu : Wiki/List Pages/then click the Key icon for your page in the list).

Using the object permission page of the wiki page, you turn off the "Can view page/pages (tiki_p_view)" attribute and save.
However, after loging off, and connecting as Anonymous you can still see the page.

It turns out that you have to turn off the "Can view page/pages (tiki_p_view)" AND "Can admin the wiki (tiki_p_admin_wiki)" attributes to hide the wiki page from the Anonymous group.

The interface has three tabs. The first tab is for assigning permissions.

The second tab is to select which groups should be included in the table for assigning permissions, because, when the list of groups is large, assigning permissions could be slow.

The third tab is to filter the number of features that should be shown in the interface. This is specially needed when managing category permissions, to avoid having a list bigger than needed for our purposes in specific cases.

In addition, this new interface to manage permissions includes several features:

1. You can assign or remove all object permissions on all child categories if this box is checked.
2. You can filter the whole list of permissions dynamically to list only those containing some text
3. You can expand or collapse at will any of the sections of permissions
4. You can select one by one the permissions to be assigned or checking the box at the column title (group name) level, and that selection will propagate to all the checkbox shown in that column.

• demo

Permissions can be restricted via the category feature. Basically, you can already assign all the permissions you need as described above. The full granularity of permissions can be assigned to categories (and thus inherited when objects belong to a given category).

If an object has no specific (object) permissions, then:

1. If the object is not part of any category with specific permissions, global permissions apply.
2. If the object is part of at least one category with specific permissions, the permissions on that object are the sum of the permissions granted to all of the object's categories which have specific permissions.

For example, if...

1. wiki page Foo has no specific permissions
2. the set of categories Foo is in is category #3 and category #5
3. and category #3 has no specific (category) permissions

... then:

1. If category #5 has no with specific permissions, global permissions apply.
2. If category #5 has specific permissions, the permissions on Foo are the permissions on category #5.

Because adding a category to an object can provide additional rights, it is important to protect who can assign categories to prevent undesired escalation. For example, if the site contains public and private information, someone with access to edit private information should not be able to make it available publicly by changing the categories. To resolve this issue, multiple permissions can be assigned to the categories.

To begin with, tiki_p_modify_object_categories allows to determine if the user is allowed to modify the categories of the object at all. Without this permission, it will be impossible to modify the categories. Typically, it is safe to grant this permission widely.

Then, there is higher granularity available for each category. tiki_p_add_object and tiki_p_remove_object determine if the user can add or remove elements from the category. Categories on which permissions are specified should also specify who can assign to or remove from those categories. When a user has the tiki_p_modify_object_categories permission on an object and modifies that object, but lacks the tiki_p_add_object permission on a certain category, the user will see a checkbox for that category, but the checkbox will be disabled.

Additionally, some category changes may be allowed in certain contexts by defining Category Transitions, which would allow to change a category only from a certain state. A group of transitions create a workflow.

Workspaces further facilitate management of large and complex Tiki sites.

When a group has an admin permission on a feature such as tiki_p_admin_sheet, the group will lost his admin permission for an object with local perms or categories permissions.

Since Tiki19 it is possible to customise and re-order the list of the permissions displayed under Setting => Permissions (tiki-objectpermissions.php). Super user can edit a yaml file located at : tiki-objectpermissions_order.yml.

Some information on this page is from Tiki for Dummies Smarties, copyright (C) by Rick Sapir, published by KeyContent.org, and available under a Creative Commons Attribution-Share Alike License.

• ACL
• ACLs
• permission
• Permission
• perm
• perms
• right
• rights
• global permissions
• global permission
• object permission
• object permissions
• privilege
• privileges
• category permission
• category permissions