Feature Request: Common Alert Protocol (CAP) support



Common Alert Protocol (CAP) - A frequently supported feature by many digital signage solutions allowing an alert message to be quickly pushed to digital signs, ‘overriding’ the existing layout content.

User Story

It is common to run into requests for this relatively frequently, especially from Universities, Health Care, or Government organizations requiring the solution to be tied into some sort of unified alerting system, (but increasingly from private companies as well). The lack of this functionality tends to make Xibo less attractive to customers looking for this built-in functionality in their RFPs, and digital signs are the obvious destination where alerting systems would want to push these emergency messages. CAP seems like the most universally established standard for this functionality.

For the dev team to fill in:


The current status and the username of the:

  • Reporter
  • Drafter
  • Implementer


A broad description of the changes required.

Effected Software

Which parts of Xibo are effected

DB Schema Changes

Any necessary DB Schema Changes


This is an interesting request - almost all of the hard work for this is done already (push messaging, layout overrides, etc) and in use via API integrations with other commercial alerting systems.

I’m not clear on how the CAP feed arrives at the CMS though - is it designed to be pushed or pulled?


That’s a good question. I’m guessing it’s pulled. I know it’s an XML based technology, and I am aware of some resources that may clarify that, however:

Here’s the Wikipedia link: https://en.wikipedia.org/wiki/Common_Alerting_Protocol
Here’s the link to the OASIS CAP 1.2 specification: http://docs.oasis-open.org/emergency/cap/v1.2/CAP-v1.2-os.html
And here’s a link to an existing PHP library for handling CAP on Git: https://github.com/AT-backbone/Cap-PHP-library

I imagine these might help?


After poking around a bit more, it looks like some implementations allow for push and pull sources, although I’m not sure what the mechanism behind this is, (https://www.weather.gov/documentation/services-web-alerts lists both push and pull sources for CAP content).