Logger class abstract

Logger is used to emit logging messages.

There are three types of Logger: hierarchical logger - named logger using a hierarchical dot-separated namespaces; detached logger - optionally named logger that isn't part of any logger hierarchy and noop logger - logger that does nothing.

Logger objects may be obtained by calling Logger.getLogger, Logger.detached or Logger.noop factories. Logger.getLogger returns a hierarchical logger by either creating it or obtaining existing one. Logger.detached always returns a new logger regardless to the provided logger name, typically such loggers are necessary if short-living logger is needed which may be garbage collected later. Logger.noop returns a no operation logger.

Each logger has a severity level reflecting a minimum severity level of logging message this logger cares about (see Logger.level). It's possible to register a logging message filter that filters messages based on various criteria (see Logger.filter).

To log a message use Logger.log method or one of its derivatives such Logger.debug, Logger.info, etc. On each Logger.log calls logger performs a severity level check and discarding those messages which have severity level this logger doesn't cares about; if message passes severity level check it then filtered out by a registered logger filter if any. Those messages which pass both checks delegated to a registered handler if any (see Logger.handler).

To bind structured data to the logging context call Logger.bind with data represented as a collection of Fields. Calling to Logger.bind will result into a new context with logging capabilities and bound collection of fields has been created.

Implemented types
Implementers
Available Extensions

Constructors

Logger.detached([String? name])
Creates a new detached logger.
factory
Logger.getLogger(String name)
Retrieves a logger with name. If the logger already exists, then it will be returned, otherwise a new logger is created.
factory
Logger.noop([String? name])
Creates a new noop logger which never emits logs and never delegates records to handlers.
factory

Properties

filter ← Filter?
Set this logger filter.
no getter
handler ← Handler?
Sets this logger logs handler.
no getter
hashCode → int
The hash code for this object.
no setterinherited
level ↔ Level
Retrieves minimum severity level of Records this logger cares about.
getter/setter pair
name → String?
Name of this logger.
no setter
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

bind([Iterable<Field>? fields]) → Interface
Creates and returns a new logging context with bound collection of fields added to existing one.
inherited
isEnabledFor(Level level) → bool
Tests whether record with severity level will be emitted by this logger.
log(Level level, String message) → void
Emits a record with message and level severity level.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited
trace(String message, {Level level = Level.debug}) → Tracer
Starts tracing and emits a record with message and level severity level; to stop tracing call Tracer.stop on the returned tracer.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited

Static Properties

root → Logger
The root logger represents a topmost logger in loggers hierarchy.
no setter