Can I Filter different log levels to different backends. about minilog

[mixu]

Thanks for filing these issues! I'll have to think about the other one a bit more before replying, but yes, this is possible.

The logger in Minilog is an event emitter and every pipe() configures a new listener (or listener chain, e.g. logger -> filter -> backend) so yes, you can do that.

You need to create a new instance of Minilog.Filter for each backend, and configure it to with different exclusions. See the Minilog.Filter docs at http://mixu.net/minilog/filter.html

I'll add a better example for this, so keeping this issue open for now.

[nevf]

It seems that I'd need:

logger -> filter -> backend
      |-> filter -> backend

and I can't see how you'd do that.

Looking forward to the example.

[mixu]

Here's an example:

var fs = require('fs'),
    Minilog = require('minilog');

// console logging
Minilog
  // blacklist: level >= info
  .pipe(new Minilog.Filter().deny('foo', 'info'))
  .pipe(Minilog.backends.console.formatNpm)
  .pipe(Minilog.backends.console);

// file logging
Minilog
  // blacklist: level >= warn
  .pipe(new Minilog.Filter().deny('foo', 'warn'))
  // Stringifier adapter is needed for piping to
  // writable streams that want strings (e.g. Node native streams)
  .pipe(new Minilog.Stringifier())
  .pipe(new fs.createWriteStream('./test.txt'));

// do some logging

var log = require('minilog')('foo');

log
  .debug('debug message')
  .info('info message')
  .warn('warning')
  .error('this is an error message');

... and after this, you should see the log lines where level >= info on the console, and log lines where level >= warn in the file.

[nevf]

Very neat, thanks - just what I was looking for.