Just a simple logging module for your Electron or NW.js application. No dependencies. No complicated configuration. Just require and use. Also, it can be used without Electron in any node.js application.
By default it writes logs to the following locations:
- on Linux:
~/.config/<app name>/log.log - on macOS:
~/Library/Logs/<app name>/log.log - on Windows:
%USERPROFILE%\AppData\Roaming\<app name>\log.log
Install with npm:
npm install electron-log
const log = require('electron-log');
log.info('Hello, log');
log.warn('Some problem appears');Documentation for v2.x is here. Read the migration guide to update to v3.x
electron-log supports the following log levels:
error, warn, info, verbose, debug, silly
Transport is a simple function which does some work with log message. By default, two transports are active: console and file.
If you change some transport options, make sure you apply the changes both in main and renderer processes.
You can set transport options or use methods using:
log.transports.console.format = '{h}:{i}:{s} {text}';
log.transports.file.clear();
Just prints a log message to application console (main process) or to DevTools console (renderer process).
- format, default
'%c{h}:{i}:{s}.{ms}%c › {text}'(main),'{h}:{i}:{s}.{ms} › {text}'(renderer) - level, default 'silly'
- forceStyles, use styles in the main process even if TTY isn't attached, default false
The file transport writes log messages to a file.
- fileName, default 'log.log'
- format, default
'[{y}-{m}-{d} {h}:{i}:{s}.{ms}] [{level}] {text}' - level, default 'silly'
- maxSize of log file in bytes, 1048576 (1mb) by default.
Detailed description of file transport options and methods.
When logging inside main process, it shows log in DevTools console too. This transport can impact on performance, so it's disabled by default for packaged application.
When logging inside renderer process, it shows log in application console too. This transport can impact on performance, so it's disabled by default for packaged application.
Sends a JSON POST request with ILogMessage in the body to the specified url.
- level, default false
- url
Just set level property to false, for example:
log.transports.file.level = false;
log.transports.console.level = false;Transport is just a function (msg: ILogMessage) => void, so you can
easily override/add your own transport.
More info.
Colors can be used for both main and DevTools console.
log.info('%cRed text. %cGreen text', 'color: red', 'color: green')
Available colors:
- unset (reset to default color)
- black
- red
- green
- yellow
- blue
- magenta
- cyan
- white
For DevTools console you can use other CSS properties.
electron-log can catch and log unhandled errors/rejected promises:
log.catchErrors(options = {});
- showDialog, default true for the main process. Set it to false to prevent showing a default electron error dialog
- onError, (error) => void | false, default null - attach a custom error handler. If the handler returns false, this error will not be processed.
In some situations, you may want to get more control over logging. Hook is a function which is called on each transport call.
(msg: ILogMessage, transport: ITransport) => ILogMessage
Licensed under MIT.