LogAppender class abstract

One output of the logging system: it receives every log record that passes the logger levels and writes it somewhere.

The starter's outputs are appenders too: the console (ConsoleAppender), the in-memory buffer (LogBuffer) and the log file (FileAppender). Extend this class when records must also go somewhere else, such as a crash reporter, a remote log service or a database; implement write, and set threshold to keep only the important records. Add it with LoggingSystem.addAppender. An appender that throws does not stop the others.

// Errors also go to the crash reporter, with their stack trace.
class CrashReportAppender extends LogAppender {
  CrashReportAppender() : super(threshold: SpringLogLevel.error);

  @override
  void write(SpringLogRecord record) =>
      crashReporter.log(record.message, record.error, record.stackTrace);
}

LoggingSystem.instance.addAppender(CrashReportAppender());

Spring (Java): a Logback Appender, usually an AppenderBase subclass declared in logback-spring.xml. Here it is added in code.

Constructors

LogAppender({SpringLogLevel threshold = SpringLogLevel.trace})

An appender that writes records of threshold and above (every level by default).

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

threshold ↔ SpringLogLevel

The lowest level this appender writes, checked after the logger levels; SpringLogLevel.off writes nothing.

getter/setter pair

Methods

append(SpringLogRecord record) → void

Called by the logging system for each record: passes it to write when it is at or above threshold, and drops it otherwise.

close() → void

Releases what the appender holds, such as an open file. Called by LoggingSystem.removeAppender; does nothing by default.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

write(SpringLogRecord record) → void

Writes record to this output. Implement it in a subclass; the record has already passed threshold. It runs synchronously on the logging call, so slow work (a network call) should be queued.

Operators

operator ==(Object other) → bool

The equality operator.

inherited