Provide invitation of new users

As us being a research university it would be very helpful, if our employed staff (and students) could work together on international research projects within Confluence. That requires external users having user-level access to our Confluence installation. External people having an account could currenty be done by either

• self-subscribing, or
• managing external users in our universities LDAP server.

Activating self-subsription in Concluence means, anyone in the world can be a member of our enterprises' communication system, which is not acceptable. Managing external users in LDAP is also not a viable way.

Instead, it would be a GOOD THING to have, if members of the organization would be enabled to explicitly invite other non-organization people to Confluence. Those new members would receive an invitation email with a link to approve the membership, and only those invited people would become members of the Confluence installation.

In addition, it would be required for the new account to follow a (configurable, e.g. by specifying a regular expression to match) user name pattern to not conflict with the delegated user database.

It could also be helpful, if this invitation right would be a dedicated right assignable by LDAP for a group of users, but probably not all.

A first implementation hint for a plugin comes from the Atlassian support (thanks guys!):

• an 'enter new invitation' XWork action with Web UI module, which...
• records the invitee's email address together with a secret value in Bandana, and...
• sends an email to the invitee with a link to...
• an 'accept invitation' XWork action, which...
• validates the secret value in the URL against Bandana, and...
• adds the new user to Confluence with details they provide.

This is a feature common in other CMS and similar systems and would be a major improvement for Confluence, the Enterprise wiki.