Changes in Wikis have to be reviewed – this does not only apply to open and public setups, but to closed sites as well. While dealing with spam and vandalism is unnecessary in closed wikis, the semantic correctness of a change still has to be verified by other participants. Moreover, page edits may imply changes to real-world conditions people have to or want to keep track of.

In enterprise wikis, the wiki itself is not the main focus of people’s work – it is just a tool. Depending on their field of work they might not regularly visit the wiki and just use it as a reference now and then. Hence to keep up to date, a special notification mechanism using a different medium is necessary.

On the net, feed readers are ubiquitous today. In enterprises, unfortunately, feed readers are still not widely used or even installed. So, different means of notification are needed. The single one, world-wide accepted medium suitable for this purpose is email.

DokuWiki already has an email subscription feature, but it’s very basic and barely usable: For every single edit on a subscribed page or namespace, an email is sent. When an inexperienced person is not using the DokuWiki preview or does many changes, a subscriber is easily flooded with mails. This reduces attentiveness, interrupts people, costs time, and may even obfuscate the real changes that happened, thus defeating the very purpose of notifications.

After these thoughts, the necessity for less obtrusive email notifications for the ICKE 2.0 project was obvious. For this purpose, two additional subscription styles were introduced: digests and lists of changes. Both types of mails are not sent immediately after a page edit, but aggregate changes for a fixed time before notifying. Both types differ in the content and count of mails the user receives:

• Digest emails are sent for every single page that has been changed. They summarize changes since the last digest email was sent.
• List emails are only valid for namespaces. They list pages in the subscribed namespace which were changed since the last email was sent.

To integrate the new subscription styles without cluttering the GUI, a new subscription management screen was added to DokuWiki. In the future, 3rd party plugins may hook into this interface to add additional subscription modes like XMPP, Twitter DMs or whatever else you can imagine.

The new subscription styles allow to monitor a wiki via email without being flooded. This is an important step in adapting DokuWiki for enterprise intranet usage. The changes are available in the DokuWiki devel repository.