Robot Notifications with ElasticLib

Elastic supports sending notifications to the dashboard via robot code. This could be helpful in situations where you want to grab the attention of the user when something goes wrong or if there's an important warning to display.

Sending notifications via robot code requires the use of ElasticLib. Currently the only supported languages are Java and C++, but contributions for a Python port are open.

Installing ElasticLib

For Java projects, copy this file into your robot project: https://github.com/Gold872/elastic-dashboard/blob/main/elasticlib/Elastic.java

If you are using C++, you will have to copy these 2 files instead:

1. https://github.com/Gold872/elastic-dashboard/blob/main/elasticlib/elasticlib.h

2. https://github.com/Gold872/elastic-dashboard/blob/main/elasticlib/elasticlib.cpp

For Python projects, you will have to copy this file: https://github.com/Gold872/elastic-dashboard/blob/main/elasticlib/elasticlib.py

It is recommended to put this in a folder called util, however any location within a robot project works. Depending on where the file is located, you may need to change the top line of the file.

Creating a Notification

Notification data is stored in an object called Notification. Currently, this has the following properties:

• level for the type of notification

• title for the notification title

• description for the notification text

• width for the notification width (optional)

• height for the notification height (optional)

• displayTimeMillis for the time to show the notification in milliseconds (optional)

There are 3 notification levels:

1. Error

2. Warning

3. Info

An example of a Notification for an error notification would be

Java

Elastic.Notification notification = new Elastic.Notification(Elastic.NotificationLevel.ERROR, "Error Notification", "This is an example error notification.");

C++

elastic::Notification notification = {.level = elastic::NotificationLevel::ERROR, .title = "Error Notification", .description = "This is an example error notification"};

Python

notification = Notification(level=NotificationLevel.ERROR, title="Error Notification", description="This is an example error notification")

Sending a notification

In order to send a notification, there is a method called sendNotificationin the Elastic class to send a Notification.

To send the error notification that was declared above, you would call

Java

Elastic.sendNotification(notification);

C++

elastic::SendNotification(notification);

Python

send_notification(notification)

When this is called, a popup will appear on the dashboard that looks like this

Error Notification

Customizing a Notification

Notifications and their settings can be customized after being created, allowing them to be reused.

For example, the error notification created above can be customized into a warning notification.

Java

/* code that created the notification */
notification.setLevel(NotificationLevel.WARNING);
notification.setTitle("Warning Notification");
notification.setDescription("This is an example warning notification");

C++

/* code that created the notification */
notification.level = elastic::NotificationLevel::WARNING;
notification.title = "Warning Notification";
notification.description = "This is an example warning notification";

Python

# code that created the notification
notification.level = NotificationLevel.WARNING
notification.title = "Warning Notification"
notification.description = "This is an example warning notification"

Customizing with Method Chaining (Java Only)

For Java, method chaining is the simpler and recommended way to customize notifications. This allows for customizing multiple properties with just one line of code, as well as reusing only one notification object, which is better for the Java Garbage Collector performance (see WPILib docs for more details)

For example, here's how a notification can be entirely customized and sent with just one line of code.

Elastic.Notification notification = new Elastic.Notification();

/* ... */

Elastic.sendNotification(notification
    .withLevel(Elastic.NotificationLevel.INFO)
    .withTitle("Some Information")
    .withDescription("Your robot is doing fantastic!")
    .withDisplaySeconds(5.0)
);