# logging

**Repository Path**: flutter_libs/logging

## Basic Information

- **Project Name**: logging
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: BSD-3-Clause
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-12-03
- **Last Updated**: 2020-12-19

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

[![Build Status](https://travis-ci.org/dart-lang/logging.svg?branch=master)](https://travis-ci.org/dart-lang/logging)
[![Pub](https://img.shields.io/pub/v/logging.svg)](https://pub.dev/packages/logging)

## Initializing

By default, the logging package does not do anything useful with the log
messages. You must configure the logging level and add a handler for the log
messages.

Here is a simple logging configuration that logs all messages via `print`.

```dart
Logger.root.level = Level.ALL; // defaults to Level.INFO
Logger.root.onRecord.listen((record) {
  print('${record.level.name}: ${record.time}: ${record.message}');
});
```

First, set the root `Level`. All messages at or above the level are sent to the
`onRecord` stream.

Then, listen on the `onRecord` stream for `LogRecord` events. The `LogRecord`
class has various properties for the message, error, logger name, and more.

## Logging messages

Create a `Logger` with a unique name to easily identify the source of the log
messages.

```dart
final log = Logger('MyClassName');
```

Here is an example of logging a debug message and an error:

```dart
var future = doSomethingAsync().then((result) {
  log.fine('Got the result: $result');
  processResult(result);
}).catchError((e, stackTrace) => log.severe('Oh noes!', e, stackTrace));
```

When logging more complex messages, you can pass a closure instead that will be
evaluated only if the message is actually logged:

```dart
log.fine(() => [1, 2, 3, 4, 5].map((e) => e * 4).join("-"));
```

See the `Logger` class for the different logging methods.