flutter_logs

A file based advanced logging framework for Flutter Apps (Android & iOS).

pub package

Overview

Flutter Logs provides quick & simple file based logging solution. All logs are saved to files in storage path provided. A new log file is created every hour on a new log event. These logs can be filtered and sorted easily. Logs can easily be exported as zip file base on filter type. PLogs also provide functionality to arrange data logs into a predefined directory structure. Custom logs can be used for a specific events based logging within the app. Logs can be saved as encrypted for security purposes.

Flutter logs can work with Logstash by writing JSON delimited logs to log files. The format is based on ELK schema. You can also send logs in real-time to server using MQTT. MQTT configuration can be applied on Logstash to receive & view logs on kibana dashboard.

Image1

Read more about flutter_logs usage on this Medium article:

Sending logs from Flutter apps in real-time using ELK stack & MQTT

Features (Android)

  • Logs events in files created separately every hour (24 hours event based)
  • Files can be compressed and exported for time and day filters
  • Clear Logs easily
  • Save & Export Logs to app's directory as zip file
  • Custom Log formatting options
  • CSV support
  • Custom timestamps support
  • Custom file data logging support.
  • Encryption support added
  • Multiple directory structures
  • Print logs as String
  • Export all or single types of logs
  • ELK Stack Supported See more about it here.
  • MQTT Support (SSL)

Features (iOS)

Note: Work is in progress. More features will be added soon.
  • Logs events in files
  • Files can be compressed and exported
  • Clear Logs easily
  • Save & Export Logs to app's directory as zip file
  • Print logs as String

Install

In your pubspec.yaml

dependencies:
    flutter_logs: [Latest_Version]
import 'package:flutter_logs/flutter_logs.dart';

Setting Up

Initialization


In your main.dart file add like this:

   
   import 'package:flutter_logs/flutter_logs.dart';

   Future<void> main() async {
     WidgetsFlutterBinding.ensureInitialized();

     //Initialize Logging
     await FlutterLogs.initLogs(
     logLevelsEnabled: [
       LogLevel.INFO,
       LogLevel.WARNING,
       LogLevel.ERROR,
       LogLevel.SEVERE
     ],
     timeStampFormat: TimeStampFormat.TIME_FORMAT_READABLE,
     directoryStructure: DirectoryStructure.FOR_DATE,
     logTypesEnabled: ["device","network","errors"],
     logFileExtension: LogFileExtension.LOG,
     logsWriteDirectoryName: "MyLogs",
     logsExportDirectoryName: "MyLogs/Exported",
     debugFileOperations: true,
     isDebuggable: true);

     runApp(MyApp());
   }

How to log data?

You have 2 choices for logging:

Hourly Logs

Hourly logs are autumatically generated once this line is called. These logs are sorted and named according to current time (24h format) on device e.g. 0110202013.log

FlutterLogs.logThis(
        tag: 'MyApp',
        subTag: 'logData',
        logMessage:
            'This is a log message: ${DateTime.now().millisecondsSinceEpoch}',
        level: LogLevel.INFO);

Or simply call this:

    FlutterLogs.logInfo("TAG", "subTag", "My Log Message");
    
    FlutterLogs.logWarn("TAG", "subTag", "My Log Message");
    
    FlutterLogs.logError("TAG", "subTag", "My Log Message");
    
    FlutterLogs.logErrorTrace("TAG", "subTag", "My Log Message", Error());

This will create a new file in storage directory according to time on device. For a single date, all logs will be present in a single directory.

Custom File Logs

If you want to log data into a specific file for some events, you can do this in 2 steps:

These logs will be kept in a seperate file.

Step 1:

IMPORTANT Define log file name in logs configuration, logger needs the name to find the file on storage, otherwise no data will be logged.

Here 3 files of logs are defined, logger will use these file name as keys to write data in them.

    await FlutterLogs.initLogs(
        logTypesEnabled: ["Locations","Jobs","API"]);

Step 2:

Log data to file. You can choose to either append to file or overwrite to complete file.

    FlutterLogs.logToFile(
        logFileName: "Locations",
        overwrite: false,
        logMessage:
            "{0.0,0.0}");

Where are my logs stored?

Your logs can be found in the path of your app's directory in storage:

--> Android/data/YOUR_APP_PACKAGE/files/YOUR_LOGS_FOLDER_NAME/Logs/

Image2

Export/Print Logs

You can export logs to output path sepcified in logs configuration:

    await FlutterLogs.initLogs(
        logsExportDirectoryName: "MyLogs/Exported");

To export logs call this:

    FlutterLogs.exportLogs(
        exportType: ExportType.ALL);
    FlutterLogs.printLogs(
        exportType: ExportType.ALL);

To export custom file logs:

 FlutterLogs.exportFileLogForName(
        logFileName: "Locations");
 FlutterLogs.printFileLogForName(
        logFileName: "Locations");

Listen to export/print results:


    import 'dart:async';
    import 'dart:io';
    import 'package:flutter_logs/flutter_logs.dart';
    import 'package:path_provider/path_provider.dart';

    FlutterLogs.channel.setMethodCallHandler((call) async {
        if (call.method == 'logsExported') {
          var zipName = "${call.arguments.toString()}";

          Directory externalDirectory =
              await getExternalStorageDirectory();

          File file = File("${externalDirectory.path}/$zipName");

          FlutterLogs.logInfo(
              TAG, "path", 'Path: \n${file.path.toString()}');

          if (file.existsSync()) {
            FlutterLogs.logInfo(
                TAG, "existsSync", 'Logs found and ready to export!');
          } else {
            FlutterLogs.logError(
                TAG, "existsSync", "File not found in storage.");
          }
          
        } else if (call.method == 'logsPrinted') {
          //TODO Get results of logs print here
        }
      });

Clear Logs

 FlutterLogs.clearLogs();

Errors/Exception Logs

Printing exception logs:

      try {
          var i = 100 ~/ 0;
          print("$i");
      } catch (e) {
          FlutterLogs.logThis(
              tag: 'MyApp',
              subTag: 'Caught an exception.',
              logMessage: 'Caught an exception!',
              exception: e,
              level: LogLevel.ERROR);
      }

Printing error logs:

      try {
          var i = null;
          print(i * 10);
      } catch (e) {
          FlutterLogs.logThis(
              tag: 'MyApp',
              subTag: 'Caught an error.',
              logMessage: 'Caught an exception!',
              error: e,
              level: LogLevel.ERROR);
      }

ELK Elastic Stack Schema Support


Send additional Meta info for better filtering at LogStash dashboard. With this setting, logs will be logged as JSON-delemited.

    await FlutterLogs.setMetaInfo(
      appId: "flutter_logs_example",
      appName: "Flutter Logs Demo",
      appVersion: "1.0",
      language: "en-US",
      deviceId: "00012",
      environmentId: "7865",
      environmentName: "dev",
      organizationId: "5767",
      userId: "883023-2832-2323",
      userName: "umair13adil",
      userEmail: "m.umair.adil@gmail.com",
      deviceSerial: "YJBKKSNKDNK676",
      deviceBrand: "LG",
      deviceName: "LG-Y08",
      deviceManufacturer: "LG",
      deviceModel: "989892BBN",
      deviceSdkInt: "26",
      latitude: "0.0",
      longitude: "0.0",
      labels: "",
    );

Output of logs will be like this:

{
  "user": {
    "user.email": "m.umair.adil@gmail.com",
    "user.full_name": "umair",
    "user.id": "17282738",
    "user.hash": "1",
    "user.name": "Umair"
  },
  "message": "{OkHttpClient}  {X-XSS-Protection: 1; mode=block} [30 June 2020 04:15:16 PM]",
  "@version": "1",
  "log.logger": "PLogger",
  "host": {
    "host.type": "Android",
    "host.name": "LG",
    "host.architecture": "LG 23",
    "host.hostname": "8000",
    "host.id": "LG",
    "host.ip": "0.0.0.0",
    "host.mac": ""
  },
  "labels": "{}",
  "app": {
    "app.language": "en-US",
    "app.id": "com.example.develop",
    "app.name": "Flutter Dev",
    "app.version": "0.0.108"
  },
  "process.thread.name": "DATA_LOG",
  "organization": {
    "organization.name": "debug",
    "organization.id": "BlackBox"
  },
  "geo": {
    "geo.location": "{ \"lon\": 0.0, \"lat\": 0.0 }"
  },
  "service.name": "Network",
  "@timestamp": "2020-06-30T16:27:36.894Z",
  "topic": "com.flutter.elk.logs",
  "log.level": "INFO"
}

Enable MQTT Feature


Note: PLogger currently supports SSL connection for MQTT.

Step 1:

Add certificate in your assets directory.

Step 2:

Add following line in your pubspec file.

flutter:
  assets:
     - m2mqtt_ca.crt
Step 3:

Add following block for initializing MQTT logging.

    await FlutterLogs.initMQTT(
        topic: "YOUR_TOPIC",
        brokerUrl: "", //Add URL without schema
        certificate: "m2mqtt_ca.crt",
        port: "8883");

That's it, MQTT setup is done. If only MQTT feature is required then set this flag to false to stop writing logs to storage directory:

    await FlutterLogs.initMQTT(
        writeLogsToLocalStorage: false);

Native Libraries

For more details about RxLogs visit this Wiki

Author

Flutter Logs plugin is developed by Umair Adil. You can email me at m.umair.adil@gmail.com for any queries.

Libraries

flutter_logs