Extension:StructuredDiscussions

See Flow for an overview of what this extension is planned to address over time.

See Flow/MVP for a summary of what the December 2013 implementation does, or try it.

Installing
The easiest way to install Flow is to use the MediaWiki-Vagrant appliance and enable its flow role.

To install the extension manually:

Running "update.php" will leave temporary /tmp/mw-UIDGeneratorUUID-UID-xx files that MediaWiki may be unable to open (T55791). If you get a "Permission denied" error upon first visiting a Flow board you have to delete these files.

Dependencies

 * required: Extension:Echo for notifications (e.g. replies to your post)
 * required: It is recommended to use memcached as your cache. You may encounter problems with Redis currently.
 * required/optional: Parsoid for the option to store posts as HTML which improves performance. This is how WMF wikis are configured, and hence is the most tested configuration. As of September 2014 it is required, there are bugs with format 'wikitext', e.g. . If you use MediaWiki-Vagrant, enabling Flow enables Parsoid and sets the format to 'html'.
 * optional: Extension:CLDR for human-friendly timestamps such as "3 days ago"
 * optional: Extension:VisualEditor for experimental VisualEditor support
 * bug? if you have the VisualEditor present (e.g. perhaps to provide OOjs UI),then Flow will attempt to contact Parsoid even if VE is not enabled
 * optional: Flow can integrate with Extension:AbuseFilter, Extension:SpamBlacklist, and Extension:ConfirmEdit, see /Spam
 * optional: Extension:Thanks to "Thank" users for their posts (requires Echo)
 * optional: Extension:EventLogging for analytics

Verifying installation
Visit one of the pages you enabled for Flow (see ) and try adding a topic and editing its header.

Configuration
Here are some settings you need to make in LocalSettings.php.

Enabling Flow

 * Subject to change, see T72073

You configure a wiki page to show its Flow board in place of regular page content. specifies Flow-enabled pages (use spaces, not underscores, in page titles). specifies Flow-enabled namespaces (by number). For example:

This is not intended to be a permanent solution, it is targeted to the needs of the initial limited rollout.

Parsoid configuration
If your wiki loads the VisualEditor extension, then the values you specify for Flow's Parsoid configuration variables  should probably match VisualEditor's equivalent variables.

"maximum function nesting level of '100' reached, aborting"
If you get this error, you need to set, probably in /etc/php5/apache2/php.ini.

"Exception Caught: CAS is not implemented in Xyz"
Flow invokes  and some cache implementations including   (APCBagOStuff) don't implement CAS. You probably need to use a different cache, for example install memcached and set.

Permissions
Users must have the core  permission to perform any write action in Flow. Many wikis only grant this permission to the 'user' (logged-in) or 'autoconfirmed' group.

Flow defines many actions such as  and   (see the list in ). The permissions vary depending on whether the post is your own and whether it has been moderated. For example, by default users can edit their own posts, but only users in the 'sysop' group have the  permission to edit anyone's post. You can override which groups have which permissions and what permissions are required for each Flow action; see Manual:User rights for an overview of permissions.

Migrating existing pages
does not affect subpages. So before or after setting this, you can use Special:MovePage to move the existing content of a talk page to an /Archive subpage without leaving a redirect, and in the header section of its Flow board, add a link to it, e.g.
 * Previous discussion is at SomeNamespace talk:Some Page/Archive

The script maintenance/convertNamespaceFromWikitext.php automates this namespace conversion and archiving, see Flow/Converting talk pages. It is somewhat WMF-specific, so evaluate its operation and backup your database before running it. Another script maintenance/convertLqt.php converts LiquidThreads pages and their threads to Flow boards and topics, see Flow/Converting LiquidThreads. Similar caveats apply.

Flow adds a Topic: namespace, see Extension default namespaces. You can visit Special:PrefixIndex/Topic: to see if there are existing pages that conflict with this; if so run the maintenance script maintenance/namespaceDupes.php.

Architecture
See Flow/Architecture.

Spam
See Extension:Flow/Spam for more information on how to fight spam in Flow.

Moderation
See Extension:Flow/Moderation for more information on moderation in Flow.