Using An Event Listener

For detailed information about configuration files, configuration layers and an explanation of the configuration-root placeholder used in the file paths in this section, see the Escenic Content Engine Server Administration Guide.

The event listeners executed by the Content Engine are defined in a configuration file called configuration-root/Initial.properties. To enable the NewArticleNotifier listener, therefore, you must add a declaration to Initial.properties in one or more of your configuration layers. For example:

service.60-articlenotifier=/com/mycompany/NewArticleNotifier

You must also create a properties file for the listener called NewArticleNotifier.properties, and save it in the location you have specified in the same configuration layer(s) - configuration-root/com/mycompany/NewArticleNotifier.properties in this case. The file must at least contain $class and eventManager entries. In the particular case of the NewArticleNotifier example you will also need to set the email and emailSender properties. For example:

$class=com.mycompany.events.NewArticleNotifier
eventManager=/io/api/EventManager
email=sample@mycompany.com
emailSender=/neo/io/services/MailSender

Finally, you must make sure that the email sender declared in configuration-root/com/mycompany/NewArticleNotifier.properties. is correctly configured. Create a configuration file called configuration-root/neo/io/services/MailSender.properties and configure it with appropriate settings. For example:

enabled=true
mailHost=smtp.mycompany.com
defaultSender=noreply@mycompany.com

If you have trouble running your event listener, try checking the View Services page of the escenic-admin web application or the Content Engine's log files.

Performance monitoring

If you want to use the Content Engine's HitCollector component to gather statistics about the performance of an event listener, then you can do so by adding one more line to its properties (i.e., configuration-root/com/mycompany/NewArticleNotifier.properties in the case of this example):

collector=./NewArticleNotiferCollector

You will then also need to create a configuration file for the collector you have declared (configuration-root/com/mycompany/NewArticleNotifierCollector.properties in this case):

$class=neo.util.stats.HitCollector
denominator=events handled
description=Events handled by 'com.mycompany.events.NewArticleNotifier'
failureDescription=failed events

The information gathered by the hit collector can be viewed on the escenic-admin web application's Performance Summary page. See here for information about escenic-admin.