Web-Push Notification

This type of notification is subscribed via the visualization and is completely free. The configuration of push notifications is done in the Explorer Messages.

Function Principle

When allowing notifications in the visualization, a key (Push Endpoint) is created via the Internet with the corresponding Push service. This is then saved under the respective User. Subsequently, these can be managed under the context menu Project ▸ User Management ▸ Users ▸ Push Endpoints.

On each subsequent visit to the visualization, the current key is automatically transmitted to the server and updated if necessary.

When a push message is sent, it is first delivered to the last active Push endpoint. This minimizes the response time for unreachable (dead) endpoints. Expired or invalid endpoints are automatically removed when sending in case of an error.

Notes:
To receive notifications in the desktop browser, the browser must be open.
If the endpoint temporarily has no Internet connection, delivery may be delayed by up to 24 hours.

In Core 1, only meta keys are transmitted. These can only be received if the endpoint actively establishes a connection to the server. From Core 2 and higher, complete messages including content (except images) are directly transmitted to the Push endpoint. This ensures reliable reception even without an active server connection.

Prerequisites

  • For push notifications to work, the server and client must have Internet access and possibly also be reachable from the Internet.
  • If the server cannot be reached from the Internet, a delayed error message is displayed.
  • The browser and operating system must support the HTML5 Push API. The current list can be found here: https://caniuse.com/push-api
  • The visualization must be accessible via HTTPS and have a valid certificate. On iOS, a PWA must be installed. Possibly, push notifications in iOS only work with Core 2.

Filter Target Devices

In the individual groups, further conditions for the notification can be stored. Currently, it is only possible to distinguish between desktop and mobile device. Panels do not support push messages.

Display Image

It is possible to display a webcam or an image via the push notification. For this purpose, the first image of the file attachment is used. This must be of type JPEG, PNG, or GIF. Also note that the License for using File Attachments is available.

Behavior With Multiple Ports

Currently, a unique ID per project is used for Push registration. This means that only one Service Worker (background program of the website) with push notifications is provided per device.