Annotation Logging

The @AutoLogOutput annotation can also be used to automatically log the value of a field or getter method as an output periodically (including private fields and methods). The key will be selected automatically, or it can be overriden using the key parameter. All data types are supported, including arrays and structured data types.

public class Example {
    @AutoLogOutput // Logged as "Example/MyPose"
    private Pose2d myPose = new Pose2d();

    @AutoLogOutput(key = "Custom/Speeds")
    public double[] getSpeeds() {...}
}

The key parameter can reference other fields within the same class using the syntax shown below. This is useful to disambiguate classes with multiple instances, such as swerve modules. The value of the referenced field will not be updated after the first loop cycle. Any data type convertible to a string is supported, including numbers, booleans, and strings.

public class SwerveModule {
    private final int index; // 0, 1, 2, or 3
    private final String descriptor; // "FL", "FR", "BL", "BR"

    @AutoLogOutput(key = "Module{index}/Speed") // e.g. "Module0/Speed"
    public double getSpeed() {...}

    @AutoLogOutput(key = "Odometry/ModulePose{descriptor}") // e.g. "Odometry/ModulePoseFL"
    public Pose2d getPose() {...}
}

By default, the parent class where @AutoLogOutput is used must be within the same package as Robot (or a subpackage). The following method can be called in the constructor of Robot to allow additional packages, such as a "lib" package outside of normal robot code:

AutoLogOutputManager.addPackage("frc.lib");

The addObject method can also be used to manually scan an object for loggable fields. This method should only be called during initialization:

AutoLogOutputManager.addObject(this);

warning

The parent class where @AutoLogOutput is used must also be instantiated within the first loop cycle and be accessible by a recursive search of the fields of Robot. This feature is primarily intended to log outputs from subsystems and other similar classes. For classes that do not fit the criteria above, call Logger.recordOutput periodically to record outputs.