logging

The logging library provides Python-style logging functionality, compatible with the basic Python logging interface. It uses the paularlott/logger library under the hood with slog integration.

Note: This is an extended library and not enabled by default. You must register it explicitly.

Available Functions

Registration

To use this library, you must register it:

import "github.com/paularlott/scriptling/extlibs"
import logslog "github.com/paularlott/logger/slog"

// In your main function
p := scriptling.New()

// Register with a custom logger (recommended)
loggerInstance := logslog.New(logslog.Config{
    Level:  "debug",
    Format: "console",
    Writer: os.Stdout,
}).WithGroup("scriptling")
extlibs.RegisterLoggingLibrary(p, loggerInstance)

Environment Isolation

Each Scriptling environment gets its own logger instance. This means:

• Multiple environments can have different loggers without interfering
• Loggers can have different output destinations, levels, and formats
• The logger instance is tied to the environment it’s registered with

// Environment 1
p1 := scriptling.New()
logger1 := logslog.New(logslog.Config{
    Writer: os.Stdout,
}).WithGroup("app1")
extlibs.RegisterLoggingLibrary(p1, logger1)

// Environment 2 (different logger)
p2 := scriptling.New()
logger2 := logslog.New(logslog.Config{
    Writer: someOtherWriter,
}).WithGroup("app2")
extlibs.RegisterLoggingLibrary(p2, logger2)

Functions

logging.getLogger(name=None)

Creates and returns a logger object with the specified name. If no name is provided, defaults to “scriptling”.

Parameters:

• name (str, optional): Logger name. Used as the group name in the underlying logger.

The logger name will be displayed as a nested group in the log output, e.g., [scriptling.componentName].

Returns:

• Logger object with methods for logging at different levels

Module-level logging functions

These functions provide convenient access to logging without creating a logger instance:

• logging.debug(msg) - Log a debug message
• logging.info(msg) - Log an info message
• logging.warning(msg) - Log a warning message
• logging.warn(msg) - Alias for warning (Python compatibility)
• logging.error(msg) - Log an error message
• logging.critical(msg) - Log a critical message

Logger Methods

When you get a logger using getLogger(), it returns an object with these methods:

• logger.debug(msg) - Log a debug message
• logger.info(msg) - Log an info message
• logger.warning(msg) - Log a warning message
• logger.warn(msg) - Alias for warning (Python compatibility)
• logger.error(msg) - Log an error message
• logger.critical(msg) - Log a critical message

Constants

The library defines standard logging level constants:

• logging.DEBUG = 10
• logging.INFO = 20
• logging.WARNING = 30
• logging.WARN = 30 (alias for WARNING)
• logging.ERROR = 40
• logging.CRITICAL = 50

Examples

Basic Usage

import logging

# Simple logging using module functions
logging.warning('Watch out!')
logging.info('This is an info message')
logging.error('Something went wrong')

Using Named Loggers

import logging

# Get a logger with a specific name
logger = logging.getLogger('myApp')

# Log messages with the logger
logger.debug('debug message')
logger.info('info message')
logger.warning('warn message')
logger.error('error message')
logger.critical('critical message')

Multiple Loggers

import logging

# Different loggers for different components
app_logger = logging.getLogger('app')
db_logger = logging.getLogger('database')
api_logger = logging.getLogger('api')

app_logger.info('Application starting')
db_logger.debug('Connecting to database')
api_logger.warning('Rate limit approaching')

Configuration

The default logger is configured with:

• Level: INFO
• Format: console (human-readable)
• Output: Standard output
• Group: “scriptling”

All loggers created with getLogger() will inherit these settings unless specified otherwise.

Differences from Python’s logging module

This is a simplified implementation focused on basic logging functionality:

1. No configuration API - loggers use the default configuration
2. No handlers - output is always to stdout
3. No formatters - output format is fixed
4. No filtering - all messages at the configured level are shown
5. No hierarchy - named loggers are independent (except for the shared group prefix)
6. No file logging - as per requirements

Integration with Scriptling

The logging library integrates seamlessly with Scriptling’s output capture system. All log messages will be captured along with any print statements or other output from your scripts.