Private workspaces

Private workspaces restrict their activity to non-members and restrict membership to invite/request only.

From the private workspace's dashboard or the workspace directory, if enabled, a non-member user can request to join the workspace.
The request gets stored in the workspace's group page (as an XWiki object), workspace admins receive a notification message and the request will show up in the Workspace Membership Management (WIKITHREEDOTO-24) section until:
a) An admin approves the request
b) The user cancels the request.

Next time the non-member user visits the private workspace's dashboard or sees it in the workspace directory, instead of the Join button, a "Membership awaiting confirmation" message will be shown. The user will also have the option to cancel the request if she pleases.

When the request is accepted, the user receives a notification message.