12 Formatters

The Formatter class is responsible for converting a Log Record into a String representation. For example, the FileHandler uses the function Format LogRecord.vi of the Formatter class.

The HSE Logger ships with three Formatter classes:

An improved version of the Default Formatter.

Example output:

1. Simple error
2. Error from the Error Cluster from Error Code VI with extra call chain
3. Error from the Error Cluster from Error Code VI with extra call chain and DQMH error hint

2024-03-05 14:59:32.608 - DEBUG    - Normal log message - Logging with Helper-VIs.vi
2024-03-05 15:00:07.338 - DEBUG    - Log message with error - Logging with Helper-VIs.vi
                        => Error 42: Some error.
2024-02-20 15:33:58.253 - DEBUG    - Log Message - UT_Formatter.lvlib:Test HSE_v2 Format String.vi
                        => Error 42: Some error
                        => Source call chain
                            > Navigation.lvlib:Button Manager.lvclass:Get Object by Name.vi
                            > Navigation.lvlib:Main.vi
                            > Navigation.lvlib:Main.vi.ACBRProxyCaller.724000A7
                        => DQMH error hint
                            > MHL Frame: Set Disabled State

The original, slightly improved format of the FileHandler (HSE_v1_Formatter) and default if no specific Formatter is given.

Example output:

1. Simple error
2. Error from the Error Cluster from Error Code VI with extra call chain
3. Error from the Error Cluster from Error Code VI with extra call chain and DQMH error hint

# 
2024-02-20 12:46:00.341 - DEBUG    - Test error - UT_Formatter.lvlib:Test Clean Source String.vi - 42 - Some error |  | 

# Error from the Error Cluster from Error Code VI with extra call chain
2024-02-20 12:46:00.341 - DEBUG    - Test error - UT_Formatter.lvlib:Test Clean Source String.vi - 42 - Some error | UT_Formatter.lvlib:ECFEC Wrapper.vi => UT_Formatter.lvlib:Test Clean Source String.vi | 

# Error from the Error Cluster from Error Code VI with extra call chain and DQMH error hint
2024-02-20 12:46:00.341 - DEBUG    - Test error - UT_Formatter.lvlib:Test Clean Source String.vi - 42 - Some error | Navigation.lvlib:Button Manager.lvclass:Get Object by Name.vi => Navigation.lvlib:Main.vi => Navigation.lvlib:Main.vi.ACBRProxyCaller.724000A7 | MHL Frame: Set Disabled State

Log in JSON format so that log entries can be parsed by other tools (e.g. fluent-bit log forwarder) without the need to write a custom log parser.

Example JSON lines structured log:

  {"time": "2023-10-04 08:55:12.964","log_level": "INFO","message": "Application initialized.","call_chain": "Experiment Pane.lvlib:Main.vi:4140011->Experiment Pane.lvlib:Main.vi.ACBRProxyCaller.C3000E8","error_code": "0"}
  {"time": "2023-10-04 08:55:12.964","log_level": "DEBUG","message": "Running Self-Tests","call_chain": "Experiment Pane.lvlib:Main.vi:4140011->Experiment Pane.lvlib:Main.vi.ACBRProxyCaller.C3000E8","error_code": "0"}
  {"time": "2023-10-04 08:55:12.964","log_level": "WARNING","message": "Self-Test A failed","call_chain": "Experiment Pane.lvlib:Main.vi:4140011->Experiment Pane.lvlib:Main.vi.ACBRProxyCaller.C3000E8","error_code": "1234"}
  {"time": "2023-10-04 08:55:12.964","log_level": "ERROR","message": "VISA Could not load resource.","call_chain": "Experiment Pane.lvlib:Main.vi:4140011->Experiment Pane.lvlib:Main.vi.ACBRProxyCaller.C3000E8","error_code": "5678"}

Features:

• Follows JSONlines format - https://jsonlines.org/
• One log entry per line
• Each log entry is JSON formatted
• Each line is separated by line feed
• Can expand single-line JSON using built in formatters in most text IDEs (i.e. VSCode, Shift+Alt+F)
• Scalable - can easily include nested JSON structures

You can implement your own, specific child class of the Default Formatter to adjust the conversion. To inject a Formatter use the corresponding terminal of the “Create Handler” method or the Set Formatter.vi of the Handler (or the property node).