Package edu.wpi.first.wpilibj

Class Alert

java.lang.Object
edu.wpi.first.wpilibj.Alert
All Implemented Interfaces:
AutoCloseable
public class Alert extends Object implements AutoCloseable
Persistent alert to be sent via NetworkTables. Alerts are tagged with a type of kError, kWarning, or kInfo to denote urgency. See AlertType for suggested usage of each type. Alerts can be displayed on supported dashboards, and are shown in a priority order based on type and recency of activation, with newly activated alerts first.

Alerts should be created once and stored persistently, then updated to "active" or "inactive" as necessary. set(boolean) can be safely called periodically.

This API is new for 2025, but is likely to change in future seasons to facilitate deeper integration with the robot control system. 

 class Robot {
   Alert alert = new Alert("Something went wrong", AlertType.kWarning);

   periodic() {
     alert.set(...);
   }
 }

Alternatively, alerts which are only used once at startup can be created and activated inline. 

 public Robot() {
   new Alert("Failed to load auto paths", AlertType.kError).set(true);
 }

  • Constructor Details

    • Alert

      public Alert(String text, Alert.AlertType type)
      Creates a new alert in the default group - "Alerts". If this is the first to be instantiated, the appropriate entries will be added to NetworkTables.
      Parameters:
      text - Text to be displayed when the alert is active.
      type - Alert urgency level.

    • Alert

      public Alert(String group, String text, Alert.AlertType type)
      Creates a new alert. If this is the first to be instantiated in its group, the appropriate entries will be added to NetworkTables.
      Parameters:
      group - Group identifier, used as the entry name in NetworkTables.
      text - Text to be displayed when the alert is active.
      type - Alert urgency level.

  • Method Details

    • set

      public void set(boolean active)
      Sets whether the alert should currently be displayed. This method can be safely called periodically.
      Parameters:
      active - Whether to display the alert.

    • get

      public boolean get()
      Gets whether the alert is active.
      Returns:
      whether the alert is active.

    • setText

      public void setText(String text)
      Updates current alert text. Use this method to dynamically change the displayed alert, such as including more details about the detected problem.
      Parameters:
      text - Text to be displayed when the alert is active.

    • getText

      public String getText()
      Gets the current alert text.
      Returns:
      the current text.

    • getType

      public Alert.AlertType getType()
      Get the type of this alert.
      Returns:
      the type

    • close

      public void close()
      Specified by:
      close in interface AutoCloseable