The aim of this document is to explain the Access Control List for Joomla! 1.5 as background for many references to 'permissions' and 'access' mentioned in the Getting Started documents.
Background to creating a new Joomla! 1.5 web site
There are four aspects to designing a new Joomla! web site. These also apply to planning to make alterations(including upgrading versions J1.5 to J2.5+) to an existing site or planning for transferring a site that already exists in another form into the Joomla! CMS.
- The content hierarchy:
- The content hierarchy is defined as Sections with Categories. (Another way of visualising this, Sections are the labeled drawers of a filing cabinet and Categories are the file folders in each drawer.)
- The Sections have been removed and now the content hierarchy is Categories and Subcategories.
- Who you expect to use the site and what you want them to be able to do
- The layout of the menus and the position of some functionality on the page
- The graphical design of the whole site
These should all be based on the purpose and expected content of the site, so you do need a clear idea of what you are trying to communicate and plan accordingly. Easier said than done!
Who is it written for?
You will have seen references to permissions in the documents about Articles because they can be restricted to one of the three groups (Public, Registered and Special). In creating Section, Categories and Menus, the same Access levels are available.
Permissions to do things: Access Control
There are different levels of permissions for doing things in a Joomla! Web site. In particular there is a distinction between:-
- Which users can gain access to what parts of the website? For example, will a given Menu Item be visible for a given user?
- What actions a user can perform? For example, can a user edit or publish an article?
Users are grouped together in groups. In Joomla! 1.5 these groups give robust but fairly simple distinctions. It has a coarse granularity in that you cannot set permissions to small groups or individuals.
Front-end is the web site you can see. If you are an 'Author' - you can only edit pages that you have created. So if you look at the pages done by other people - you will be able to read them but there will not be an edit icon associated with the Article. However, the list below shows that Publishers and Editors can edit any article - which sounds easy but needs some care where there are a lot of people submitting content.
Back-end is the Administrators section of the Web site.
The following lists groups and associated permissions:-
- These groups can only use the front-end of the website.
- Can view the parts of the Site that are not restricted to one of the other two groups.
- Guest Group privileges
- Can view Articles which have been given Registered Permissions
- Registered Group privileges
- Create new articles but cannot publish articles
- Edit articles they own
- View special content
- Author Group privileges
- Can edit all articles, even those that are not published
- Editor Group privileges
- Can publish articles
- These groups allow you to log into the Administrator Back-end
- Publisher Group privileges
- Can login to the Administrator Back-end
- Manager Group privileges
- Can create new users
- Can install extensions
- Administrator privileges
- Can change site template
- Can change global configuration
The permissions are allocated to usernames by the Administrator and managed through User Management interface in the Back-end of Joomla.
User permissions for a new site
You may not yet know enough about your new site to know how best to plan the management of users. The important ideas to carry forward into the next few documents on design of the content and menus is that:-
- you may want an idea of how much of the site should be open to everyone to read
- you may want to register all users, but limit them to be able to read the content without changing it.
- It is good to have some idea of whether some menus or Articles will need to be available to a restricted number of users.
- you may want some users able to add content
- you may want some users able to manage the content
- you may want one or more users to manage the site
ALC management in Joomla! 1.6 is more sophisticated and is well covered in http://docs.joomla.org/ACL_Tutorial_for_Joomla_1.6
Index to other documents in this series
--Lorna Scammell January 2011