Creating & managing groups - private, and public

Drupal Commons is based on the concept of creating Groups, associating members with those Groups, then controlling access to content based on membership.

So, when you creating a group, there are several things to do:

1. Create a group by visiting /groups, and clicking the link Add a new group.  By default, any authenticated user can create a group.
   • Some sites may not want to permit any authenticated member to create a group. To limit group creation, visit the page /admin/user/permissions, find the row for "create group content", and make sure that the checkboxes on this row are checked-on for only the roles you wish to be able to create a Group.
2. Fill out the form with details for your new group.  You can optionally upload an image to be used for this group (and it's avatar where groups are listed).
3. Set the privacy level.  Groups can have three different levels of security & privacy:
   • Public, listed.  This is the default. If the checkbox for "List in groups directory" is checked, the group will be listed on the /groups page, and the group will be visible to all users.
   • Private, unlisted. This is the opposite level of security; in this case, no users can see the group unless they are a member. Non-members attempting to visit the URL for a group of this type will not be able to see the group or its content. To get this, uncheck the "List in groups directory" checkbox, and then check the "Private group" checkbox.
   • Public, unlisted. This is a middle-ground; in this case, the group is not listed in the groups directory (/groups), which obscures it from being easily found. However, if a user knows the URL of that group (or if there is a link to it coming from somewhere else), a user can visit this group's home page and see it's content.  To get this, uncheck the "List in groups directory" checkbox and do NOT check the "Private group" checkbox.
4. Set the policy for joining the group.  Group creators can set up groups to handle membership four different ways:
   • Open. In this case, any authenticated site member can join the group unilaterally.  A "Join" link will be presented adjacent to group  names on the /groups page and in the action block at the upper-right corner of a Group home page.
   • Moderated. In this case, any authenticated site member can apply to join a group, but one of the group's administrators must approve the application.  The "Join" link will be shown at the same places as the "Open" case, but when a member applies to join, the administrators are notified (on the Group home page) of the application, which they must approve, reject, or ignore.
   • Invite-only. In this case, the no "join" link ever appears; a group administrator must manually take action to add a member to a group. This is done by clicking the "xx Members" link in the Action block (upper right corner of the Group home page), then clicking the Add Members tab, then entering the usernames of the members to be added.  Those members are notified (at next login) that they have an outstanding invitation to join the group. When they click the link to handle this, they can accept, or decline the invitation.  If they accept, they can later unilaterally decide to leave the group.
   • Closed. This case is almost the same as the Invite-only case, except that the added-user does not have the option to opt-out of the group, nor can they unilaterally leave a group. The Group administrator is in total control of group membership.