Logger Package Documentation

The logger package provides a flexible and efficient logging system for Go applications. It supports multiple logging levels, structured and simple formats, and customizable time formatting.

Installation

go get github.com/go-universal/logger

Here is an example of how to use the logger package:

package main

import (
    "fmt"
    "github.com/go-universal/logger"
)

func main() {
    // Create a logger instance
    log, err := logger.NewLogger().
        SetBufferSize(100).
        Path("./logs").
        Prefix("app_").
        Extension("log").
        Daily().
        Simple().
        StdFormatter().
        Logger()

    if err != nil {
        fmt.Println("Failed to initialize logger:", err)
        return
    }

    // Log messages at different levels
    log.Debug(
        logger.With("Name", "John Doe"),
        logger.With("Age", 30),
        logger.WithMessage("Debugging application"),
    )

    log.Info(
        logger.With("Name", "Jane Doe"),
        logger.With("Age", 25),
        logger.WithMessage("Application started"),
    )

    log.Warn(
        logger.With("Name", "Jim Doe"),
        logger.With("Age", 40),
        logger.WithMessage("Potential issue detected"),
    )

    log.Error(
        logger.With("Name", "Jake Doe"),
        logger.With("Age", 50),
        logger.WithMessage("An error occurred"),
    )

    // Flush logs before exiting
    log.Sync()
}

Types and Functions

Logger

Defines methods for logging at various levels:

• Debug(options ...LogOptions): Logs a debug-level message (development only).
• Info(options ...LogOptions): Logs an info-level message.
• Warn(options ...LogOptions): Logs a warning-level message.
• Error(options ...LogOptions): Logs an error-level message.
• Panic(options ...LogOptions): Logs a panic-level message.
• Sync(): Flushes any buffered log entries.

Logger Builder

Used to configure and create a Logger instance:

• NewLogger(): Initializes a LoggerBuilder with default settings.
• SetBufferSize(size uint): Configures the buffer size for the logger's channel.
• SetEnv(dev bool): Set development or production mode for the logger.
• SetSimple(simple bool): Set simple formatting for the logger.
• SetSilent(silent bool): Set silent mode for logger (no print to console).
• Path(root string): Sets the root directory for log files.
• Prefix(prefix string): Sets the prefix for log file names.
• Extension(ext string): Sets the extension for log file names.
• Daily(): Sets the log file layout to daily.
• Monthly(): Sets the log file layout to monthly.
• CustomLayout(layout string): Sets a custom layout for log file names.
• StdFormatter(): Sets the logger to use the standard time formatter.
• JalaaliFormatter(): Sets the logger to use the Jalaali time formatter.
• CustomFormatter(formatter TimeFormatter): Sets a custom time formatter for the logger.
• Logger(): Creates and returns a Logger instance.

Log Options

Functions to modify log entries:

• With(key string, value any): Adds extra metadata to a log entry.
• WithMessage(msg string): Adds a message to a log entry.

TimeFormatter

A function signature for time formatting:

type TimeFormatter func(t time.Time, layout string) string

Built-in formatters:

• StdFormatter: Formats time using the standard library.
• JalaaliFormatter: Formats time using the Jalaali calendar.

Log Levels

Defines the severity levels for log messages:

• DEBUG, INFO, WARN, ERROR, PANIC.

License

This project is licensed under the ISC License. See the LICENSE file for details.