To operate correctly, action=purge needs to write to the database, which
means it should be done using a POST rather than a GET request.
As of Gerrit change 310560,[1] action=purge will begin emitting a warning
when used via GET. This should be deployed to WMF wikis with 1.28.0-wmf.20,
see
https://www.mediawiki.org/wiki/MediaWiki_1.28/Roadmap for the schedule.
Clients that use action=paraminfo to determine whether to use GET or POST
for an action should automatically switch to POST; any others should
manually switch to using POST for this action as soon as possible.
To check if your client's user agent is detected making such submissions,
you can also use ApiFeatureUsage[2] and look for 'purge-via-GET' once
1.28.0-wmf.20 is rolled out to wikis your client is using.
It is planned that this warning will be changed to an error during 1.29.
Let's avoid having a repeat of T142155,[3] update your code ASAP instead of
waiting until it breaks. Thanks.
[1]:
https://gerrit.wikimedia.org/r/#/c/310560/
[2]:
https://meta.wikimedia.org/wiki/Special:ApiFeatureUsage
[3]:
https://phabricator.wikimedia.org/T142155
--
Brad Jorsch (Anomie)
Senior Software Engineer
Wikimedia Foundation