Extension:PopupAlerts

The PopupAlerts allows to add popup alerts to wiki pages with optionally specified expiration date so it can be controlled when ( and if ) users will see the popup again. It also has integrated checksum based invalidation mechanism to detect popup content change and hence reset “already-seen” markers.

Download
You can download the External Data code, in .zip format, here.

You can also download the code directly via Git from the MediaWiki source code repository. From a command line, you can call the following:

You can also view the code online here.

Installation
To install this extension, create a 'PopupAlerts' directory (either by extracting a compressed file or downloading via Git), and place this directory within the main MediaWiki 'extensions' directory. Then, in the file 'LocalSettings.php', add the following line:

Usage
popup will be seen once in 100 years

popup will be seen once in one hour (3600 seconds)

Note: if you have many popups added to the page only the first one will be taken into account. This limitation made intentionally to prevent wiki pages from being spammed with popups.