Changed Keywords: (N/A) → need-review

This extension has not been tested or used on any WMF wiki so it requires usability, performance and security reviews as well as some other things.

Extension page on MediaWiki.org: http://www.mediawiki.org/wiki/Extension:SiteWideMessages

Last year we at ShoutWiki (http://www.mediawiki.org/wiki/ShoutWiki) looked into SiteWideMessages and I ended up hacking a version which works for our setup (which, obviously, is a bit different than Wikimedia's or Wikia's). Some notes:
*the original extension is not 1:1 compatible with the trunk (or any branched version, for that matter) of MediaWiki; there are a few custom functions and some core patches that are needed
two core patches are still needed, to includes/diff/DifferenceInterface.php and to includes/User.php; both of these patches are *not* straightforward
*User.php patch changes the way of how the UserRetrieveNewTalks hook works and the original Wikia code uses a Wikia-specific global ($wgCityId) identifier of the current wiki in the User.php patch
*DifferenceInterface.php patch adds a hook called GetUserMessagesDiffCurrent in *three* different places of the code and its logic is generally speaking a bit scary
*even after I rewrote some database queries, the extension still uses plenty of subqueries and some normal queries that currently cannot be done with MediaWiki's database abstraction layer
*there's some bad i18n, mainly related to the building of expiration dates
*I had to hardcode ShoutWiki's domain in SiteWideMessages::userNewTalks (the function which is hooked into the UserRetrieveNewTalks hook)
there's plenty of ShoutWiki-specific code in my version, and obviously that should be generalized, but ironically MediaWiki doesn't deal too well with wiki farm setups by default
***for ShoutWiki's setup, we could safely assume that if there is "wiki" in the database's name, it's a MediaWiki database; the same may or may not be true for Wikimedia

Now, even if (when? :) we fix those issues, there's still a few things to take into account:

1. SiteWideMessages generally are /annoying/ -- you get the "You have new messages" bar for each SiteWideMessage until you dismiss them. Of course, the new preferences proposed in the original bug report could address this.
2. *SiteWideMessages is an extension meant for WIKI FARMS, not for individual wikis*. It's much like the CentralNotice extension http://www.mediawiki.org/wiki/Extension:CentralNotice, which is enabled on Wikimedia sites. If SiteWideMessages would be enabled on Wikimedia, there'd most likely be a very small group of users who were allowed to use it, either Wikimedia staff, stewards or an entirely new group who would have the 'sitewidemessages' user right.

If someone is interested in the ShoutWiki version of SiteWideMessages, I can commit it to the official MediaWiki Subversion repository at http://svn.wikimedia.org/.

In the light of the above, I'm suggesting either LATER or WONTFIX.

See https://www.mediawiki.org/wiki/Writing_an_extension_for_deployment for information on what is needed to get an extension reviewed before potentially deploying it on a wikisite.

Looking at the talk page for the extension, and the notice at the top:
"This extension is written for Wikia, and only works on Wikia. see the talk page"

I am going to close this for now until there is a possibility of it running on WMF-hosted wikis and there is a new community request for this.

(In reply to comment #0)

Cenarium: you may want to look into [[mw:Extension:MassMessage]] or [[mw:Extension:Echo]].