Formatters

Formatters turn a structured LogRecord into text.

Built-in formatters

Pretty formatter

ConsoleLogHandler(
  formatter: PrettyLogFormatter(
    useColors: true,
    maxStackTraceLines: 8,
  ),
)

Good default for local development.

Simple formatter

ConsoleLogHandler(
  formatter: SimpleLogFormatter(),
)

Useful when you want compact text or stable lines for parsing/export.

Formatter add-ons

ConsoleLogHandler can try specialized formatters first:

Logger.root.addHandler(
  ConsoleLogHandler(
    formatters: const [
      HttpConsoleLogFormatter(),
    ],
    formatter: PrettyLogFormatter(),
  ),
);

The first formatter whose canFormat(record) returns true wins.

That pattern is how HTTP logs can get rich request/response formatting without changing how non-HTTP records are rendered.

Choosing a formatter

• local app development: PrettyLogFormatter
• compact persistent text: SimpleLogFormatter
• Dio console diagnostics: HttpConsoleLogFormatter plus fallback formatter

Custom formatters

Implement LogFormatter when a sink needs a custom textual representation.

Prefer custom formatters over manually packing structured fields into the message string.