Introduction

The Notification Management Service for DHIS2 Notifications is designed to facilitate the handling of notifications within DHIS2. Built using NodeJS, it acts as a mediator for openHIM, providing specific functionalities to manage notifications effectively.

To know the DHIS2 event structure, you can check DHIS 2 Maintenance (psi-mis.org), program stage: CWS Notifications.

...

Endpoints

1. Schedule Notifications Endpoint

Endpoint: POST {openHIM-env}/dhis2/notification
Description: Receives requests containing notification parameters and stores them within a DHIS2 server configured through a .env file. The service analyzes the provided information and, upon verification, saves the notifications as events within DHIS2. The payload must include the TrackEntityInstance for saving notifications as events. The service will return the proper HTTP status code and message to indicate the operation result.

...

Schedule Notification

Send a POST request to {openHIM-env}/dhis2/notification with the necessary parameters including the TrackEntityInstance for each notification.

{
    //"project": string. LAC_HIV/ LAC_FP // not implemented
    //"id": string. DHIS2 TEI or Mongo ID // not implemented
    "tei": string. DHIS2 TEI, // to be discontinue (replaced by id)
    "msg": string. Message text to send,
    "channel": string. Accepted values: facebook whatsapp SMS,
    "to": string. It could be a phoneNumber or facebook/whatsapp ID,
    "templateId": string. The template ID. This ID is used for sending FBM/WA as well as for rquesting a reminder cancelation (see below),
    "templateParams": string. Template parameter. Needs parse to string the value,
    "eventDate": String. The datetime. You can check the format in the below example,
    "sendNow": boolean. Indicates if the notification is an instant message. We don't want schedule the notification.
}

Example Request for SMS:

{
    "tei": "cMyjKYJtgSI",
    "channel": "SMS",
    "templateId": "template_3",
    "msg": "hi",
    "to": "+26658636836",
    "templateParams": "",
    "eventDate": "2024-02-23T13:18:30.800Z"
}

Example Request for Facebook Messenger template:

{
    //project id
    "tei": "cMyjKYJtgSI", // change for id
    "channel": "facebook",
    "templateId": "template_3",
    "templateParams": "{'quick_replies':[{'content_type':'text','image_url':'http://example.com/img/red.png','payload':'<POSTBACK_PAYLOAD>','title':'Red'},{'content_type':'text','image_url':'http://example.com/img/green.png','payload':'<POSTBACK_PAYLOAD><','title':'Green'}],'text':'Pick a color:'}",
    "to": "1234jdj204",
    "eventDate": "2023-11-23T13:18:30.800Z",
    "sendNow": true
}

Check Meta’s documentation at https://developers.facebook.com/docs/messenger-platform/send-messages/quick-replies for quick reply format and other formats that you may want to use to send your messages

We also can send a bundle of notifications:

{
    "notifications": [
      { ... },
      { ... },
      { ... }
    ]
}

Example Request:

{
  "notifications": [
    {
        //project --> to be added
        "tei": "cMyjKYJtgSI", // replace by id
        "msg": "hi",
        "channel": "facebook",
        "to": "+26658636836",
        "templateId": "1",
        "templateParams": "",
        "eventDate": "2023-11-23T13:18:30.800Z"
    },
    {
        "tei": "cMyjKYJtgSI",
        "msg": "hi",
        "channel": "facebook",
        "to": "+26658636836",
        "templateId": "3",
        "templateParams": "",
        "eventDate": "2023-11-23T13:18:30.800Z"
    }
  ]
}

2. Cancel Notifications Endpoint

...

Canceling by Track Entitiy ID, we will cancel all the TEI events.

Canceling by event ID, we will cancel a single event.

...

Here we are going to see two examples of how to cancel a notification

Input by TrackEntity ID

Request: PUT {openHIM-env}/dhis2/cancel-notification

Attributes:

• tei: The unique identifier associated with the Track Entity.

Body Request:

{ 
  //project --> to be added
  "tei": "019283SFD" // replace by id
}

Input by Event ID

Request: PUT {openHIM-env}/dhis2/cancel-notification

Attributes:

• eventId: The unique identifier associated with the Event.

Body Request:

{ 
  //project --> to be added
  "eventId": "A019283FD"  // add project
}

Input by TrackEntity ID & TemplateId

Request: PUT {openHIM-env}/dhis2/cancel-notification

Attributes:

• tei: The unique identifier associated with the Track Entity.

• templateId: It could be a string or array. Its value is the template identifier associated with the type of message to be canceled.

Body Request:

{ 
  //project --> to be added
  "tei": "019283SFD", // replace by id
  "templateId": ["template_3","appointment"],
}

Body Request:

{ 
  //project --> to be added
  "tei": "019283SFD", // replace by id
  "templateId": "template_3",
}

Response

Upon successful cancellation, a confirmation response will be returned. If the operation encounters an issue or the notification cannot be canceled, appropriate error messages will be provided.

This cancel-notification endpoint allows for the cancellation of notifications either by the Track Entity ID or by the Event ID, providing flexibility in managing and removing notifications from the system. Adjust the specifications or examples as needed to align with your service implementation.

3. Message sending Endpoint

Endpoint: POST {openHIM-env}/dhis2/send-notifications
Description: Triggered by a cron job, this endpoint retrieves scheduled messages based on date ranges and the event status set as 'scheduled.' It prepares message content to be sent to a messaging service. After sending the messages, this service updates the event status and adds notes in case of message delivery failure or errors encountered within the messaging service.

We are using the cron service provided by OpenHIM.

The reason to do it by date ranges are both:

...

DHIS2 endpoints restrictions

...

Notifications Mediator service allows external tools to setup and schedule notifications for clients. This notifications act as reminders, so the user are aware of future activities. This, together with the Communication Mediator Service, allows the sending of the notifications through different communication channels.

Page content:

How does it works?

The following steps explains how does all the technology stack works together:

1. An external tool wants to perform an action on Notification Mediator Service.

2. The request goes to OpenHim that acts as an API Gateway.

3. OpenHim sends the request directly to the Notification Mediator Service to handle the operation.

4. Notification Mediator Service executes either:

   1. A request information to a data persistence tool to retrieve data.

   2. A delivery of information to the Communication Mediator Service.

5. After all the processes are executed, the Notifications Mediator service responds back to OpenHim.

6. OpenHim delivers a response to the external tool, letting the external tool to know if something went wrong or if everything was successful.

The following diagram shows how the technology stack is connected:

...

...

Cronjob

Notification Mediator Service use a cron scheduler to send all the notifications that have already reached the scheduled date and which status is set to 'scheduled'. This CronJob runs every 2 minutes.

The cronjob uses notification endpoint named send notifications.

There are two main reasons to do it by date ranges:

• DHIS2 endpoints restrictions

• Notifications pending to send are retrieved before the current minute and after the previous 7 days. In this This way, if for some reason we have notifications pending to send for any reason (the server was down, DHIS2 was not working in the previous hours…) we can send the previous notifications.

...

Scheduled Notifications

Trigger the cron job to send scheduled notifications by sending a POST request to {openHIM-env}/dhis2/send-notifications. Executing this, we will send the notifications until the current minute. We don’t need to add any information on the payload

Conclusion

...

• Image Added