Live updating templates connected to MQTT topics.

This scomp renders templates that are automatically rerendered after a publication to a MQTT topic.


This scomp is provided by mod_mqtt, this must be enabled.


An example of a template showing the newest content of a resource:

{% live template="_detail.tpl" topic=id id=id %}

This renders the template _detail.tpl. If the resource with id id is updated then the template will be replaced with a freshly rendered template.

The scomp can subscribe to multiple topics at once.

Live topics

Any MQTT topic can be used. The topics are interpreted as local to the page. There are three special topics:

  • Use any integer to map to the resource’s update topic. For example if id is 1234 then the topic will be ~site/rsc/1234
  • Use the tuple {object id=... predicate=...} to listen to changes of a specific predicate of a page. An example of a mapped topic is ~site/rsc/1234/o/author
  • Use the tuple {object id=...} to listen to changes of outgoing connections from a page. An example of a mapped topic is ~site/rsc/1234/o/+
  • Use the tuple {subject id=... } to listen to changes of incoming connections to a page. An example of a mapped topic is ~site/rsc/1234/s/author

Live actions

It is possible to wire actions or postbacks to a MQTT topic.

Use {% wire type={mqtt topic=... topic=...} %} to connect to one or more MQTT topics.


{% wire type={mqtt topic="~site/public/hello"} action={growl text="hello"} %}

And in Erlang this will trigger the above growl:

z_mqtt:publish(<<"~site/public/hello">>, <<>>, z_acl:sudo(z:c(mysite))).

See also scomp-wire