logform-rs

A flexible log formatting library for Rust, inspired by the Node.js logform package.

use logform::{combine, colorize, json, printf, timestamp, LogInfo};

let format = combine(vec![
    timestamp(),
    colorize().with_option("colors", r#"{"info": ["blue"]}"#),
    printf(|info| format!("{} - {}: {}", info.meta["timestamp"], info.level, info.message)),
]);

let mut info = LogInfo::new("info", "Hello, logform-rs!");
let formatted_info = format.transform(info, None).unwrap();
println!("{}", formatted_info.message);

Features

• Composable log formats
• Various built-in formats
• Extensible with custom formats
• Chainable options for each format

Table of Contents

• LogInfo Objects
• Formats
  • Align
  • Colorize
  • Combine
  • JSON
  • Ms
  • PrettyPrint
  • Printf
  • Simple
  • Timestamp
  • Uncolorize

LogInfo Objects

The LogInfo struct represents a single log message:

pub struct LogInfo {
    pub level: String,
    pub message: String,
    pub meta: HashMap<String, Value>,
}

Formats

Align

The align format adds a tab character before the message.

let aligned_format = align();

Colorize

The colorize format adds colors to log levels and messages.

let colorizer = colorize()
    .with_option("colors", r#"{"info": ["blue"], "error": ["red", "bold"]}"#)
    .with_option("all", "true");

Combine

The combine format allows you to chain multiple formats together.

let combined_format = combine(vec![
    timestamp(),
    json(),
    colorize().with_option("colors", r#"{"info": ["blue"]}"#),
]);

JSON

The json format converts the log info into a JSON string.

let json_format = json();

Ms

The ms format adds the time in milliseconds since the last log message.

let ms_format = ms();

PrettyPrint

The pretty_print format provides a more readable output of the log info.

let pretty_format = pretty_print().with_option("colorize", "true");

Printf

The printf format allows you to define a custom formatting function.

let printf_format = printf(|info| {
    format!("{} - {}: {}", info.meta["timestamp"], info.level, info.message)
});

Simple

The simple format provides a basic string representation of the log info.

let simple_format = simple();

Timestamp

The timestamp format adds a timestamp to the log info.

let timestamp_format = timestamp()
    .with_option("format", "%Y-%m-%d %H:%M:%S")
    .with_option("alias", "log_time");

Uncolorize

The uncolorize format removes ANSI color codes from the log info.

let uncolorize_format = uncolorize();

Usage

To use logform-rs in your project, add it to your Cargo.toml:

[dependencies]
logform = "0.1.0"

Then, in your Rust code:

use logform::{LogInfo, combine, timestamp, json};

let format = combine(vec![
    timestamp(),
    json(),
]);

let info = LogInfo::new("info", "Test message");
let formatted_info = format.transform(info, None).unwrap();
println!("{}", formatted_info.message);

Testing

Run the tests using:

cargo test

License

This project is licensed under the MIT License.

Acknowledgements

This library is inspired by the logform package for Node.js.