send_log 1.0.1

Log support with e-mail sending.

Send Log

A straightforward logging solution.

Log is sent to the console in debug mode (using ANSI color codes), to a file in release mode. It can be configured to use the log file in debug mode, too.

The log is rotated among a specified number of files with the specified sizes.

Unlike other logging solutions, this one closes and flushes the log file with each write. This is obviously less efficient but it makes it possible to write to the same log file from different sources (eg. both from the Dart side and your underlying platform code).

The module has a call to pack the current log files into a ZIP archive and send it attached to an e-mail address. Its main intended use case is to support an Ask for help item in the Settings page of an app that attaches the log to a support request sent by the user.

Usage

Call the constructor from your main() function:

void main() async {
  SendLogger(
    /// This name will appear as sender in the log lines, making it easier to spot them in Logcat.
    'YourAppName',
    /// The number of rotated log files kept. Defaults to 3.
    keepRotateCount: 5,
    /// File size limit to be exceded for a new log file. Defaults to 10 MB.
    rotateAtSizeBytes: 50 * 1024 * 1024,
    /// The frequency of rotation checks. Defaults to 5 minutes.
    rotateCheckInterval: const Duration(minutes: 10),
    /// Whether to send debug logs to console (false) or file (true). Defaults to false.
    /// Release and profile modes always send to file.
    logFileInDebugMode: true,
  );
  runApp(...);
}

As soon as the constructor was called, you can use the following functions from anywhere in your code:

logInfo(String prefix, Object? message, [Object? error, StackTrace? stackTrace]);
logDebug(String prefix, Object? message, [Object? error, StackTrace? stackTrace]);
logWarning(String prefix, Object? message, [Object? error, StackTrace? stackTrace]);
logError(String prefix, Object? message, [Object? error, StackTrace? stackTrace]);

• The prefix will be prepended to the message.
• The message itself can be either a string or any object that has a toString() function.
• The error itself (practically an Exception or an Error) and the stackTrace will be suppressed in release mode and printed otherwise.

A convenience function helps to print a formatted hex dump. It requires an integer list (which could be an Uint8List):

logHexDump(String prefix, Object? message, List<int> data, {int rowSize = 16, bool showAscii = true});

The required log level can be changed at any time using the usual Level values:

setLogLevel(Level.FINE);

Sending the logs can be initiated with:

await SendLogger.launchEmailLog('YourAppName', '[e-mail]', 'message body');

which will call the e-mail app of the user's choice with the subject "Log (YourAppName)", the recipient address and the initial message body filled. The plugin will not send the message, this is up to the user to decide. It only starts the e-mail and attaches the zipped log files. However, it will return a logical value that you can use to decide what message to present to your user about success or failure.

Status

The plugin is in current use in several actively published Android apps and users regularly and successfully send support requests with it. It isn't tested on iOS thoroughly, although the code is supposedly present. Tests and reports, as well as possible PRs on iOS and other platforms are, of course, welcome.