We use a custom Piwik plugin, that takes care of archiving daily campaign referrer visits on a quarter-hour basis.

The plugin is working with Piwik 2. We need to investigate if it is still working with Piwik 3 (and if not apply the necessary changes to it).

Acceptance criteria:

• The plugin archives data produced by visits including piwik_campaign and piwik_kwd in the query string is being archived during the general archiving cron job.
• The plugin adds a sub-entry to the Referrers menu
• The plugin provides an API ("CampaignVisitorsByTime." method) consumable by the "Fundraising Operation Center"
• Create tests, especially for the Archiver class
• Create CI (PHPCS, PHPMD, maybe more stuff, see FundraisingFrontend repository for reference) for CampaignVisitorsByTime repository

Background:

• See: https://github.com/wmde/CampaignVisitorsByTime/