Configure Evergreen Action Triggers

This guide is for the Evergreen Administrator. It will help you set up your Evergreen (EG) server for sending a push notifications with an action trigger. It assumes that your System Administrator has already installed the hemlock-sendmsg daemon, and it's listening on localhost:8842.

The process is:

• Create User Setting Types
• Create an Action Trigger

Create User Setting Types

This procedure creates two new User Setting Types for the app to store its push notification token and an enabled flag. The token uniquely identifies the app installation, and is required to send a push notification to a specific patron account. The boolean flag can be used as an opt-in setting type on any action triggers that send push notifications.

As an EG admin, login to the Staff client and go to Server Administration >> User Setting Types.

Procedure:

• Click New User Setting Type

• Set the following form values:

  Label	Value
  Datatype	string
  Description	Used by the Hemlock app to store a patron's push notification token
  Label	Hemlock Push Notification Data
  Name	hemlock.push_notification_data
  OPAC/Patron Visible	checked

• Click Save

• Click New User Setting Type

• Set the following form values:

  Label	Value
  Datatype	bool
  Description	Used by the Hemlock app to flag that a patron has a push notification token
  Label	Hemlock Push Notification Enabled
  Name	hemlock.push_notification_enabled
  OPAC/Patron Visible	checked

• Click Save

Create an Action Trigger

This procedure adds an action trigger to a demo server loaded with the concerto sample data. The action trigger uses the CallHTTP reactor to send a request to the hemlock-sendmsg daemon to send the push notification.

As an EG admin, login to the Staff client and go to Local Administration >> Notifications / Action Triggers.

Checkout the Evergreen Action Trigger documentation for more information.

Cloning an Existing Action Trigger

tip

Cloning an existing action trigger is a good way to start especially if you are not familiar with action triggers. It is easier to modify an existing action trigger than to create one from scratch and can help reduce errors and save time on troubleshooting.

• Make sure that you clone a working action trigger.
• Clone an action trigger that uses the same hook as the one you want to create.

1. Right click an existing event definition and click Clone Selected or select the event definition and click Clone Selected from the Actions menu.
2. When prompted to clone the environment, select Yes.
3. Set the reactor to CallHTTP.
4. Set the template according to the sample template below.

Creating an Action Trigger from Scratch

warning

Creating an action trigger from scratch can be tricky as the environment and parameters of action triggers can be complex. Only create an action trigger from scratch if you are certain you can do so.

This example event definition is for a courtesy notice. Some details may need to be adjusted for your specific use case. It is most important to set the reactor to CallHTTP and the template according to the sample template below.

• Click New Event Definition

• Set the following form values:

  Label	Value
  Owning Library	CONS
  Hook	checkout.due
  Processing Delay	-300 days
  Processing Delay Context Field	due_date
  Processing Group Context Field	usr
  Reactor	CallHTTP
  Validator	CircIsOpen
  Event Repeatability Delay	00:00:30
  Max Event Validity Delay	-300 days
  Opt-In Setting Type	hemlock.push_notification_enabled
  Opt-In User Field	usr
  Retention Interval	6 mons
  Template	(see below)
  Context Bib Path	target_copy.call_number.record
  Context Item Path	target_copy
  Context Library Path	circ_lib
  Context User Path	usr

Sample Template

Whether cloning an existing action trigger or creating a new one, the template should be set as follows. The parameters title, body, and type will vary depending on the type of notification you want to send.

method get
url http://localhost:8842/send
  
[%- USE date -%]
[%- user = target.0.usr -%]
[%- homelib = user.home_ou -%]
  
<Parameters>
  title Courtesy Notice
  body You have a item due

  # the push notification type (optional)
  # controls the app screen that launches when you tap the notification. 
  # fines, general, holds, pmc, checkouts
  type checkouts

  # if the patron is not a mobile app user, token will be empty;
  # this does no harm and allows hemlock-sendmsg to keep a metric of all send attempts
  token [%- helpers.get_user_setting(user.id, 'hemlock.push_notification_data') %]

  # username is used by the app if there are multiple accounts on the device;
  # barcode might be better but the app does not currently store that
  username [%- user.usrname %]

  # debug=1 causes hemlock-sendmsg to log requests on stdout
  debug 1
</Parameters>

• Click Save