logly

A minimal logging utility to support verbose and debug modes

logly

logly is a small logging framework in the nodejs ecosystem that also allows one to set debug or verbose logging modes. It is useful to replace comments that describe what the code is doing, especially in debug mode.

var logly = require( 'logly' );
 
logly.name( 'myapp' );
logly.mode( 'debug' );
 
logly.debug( 'debug log' );
// stdout: myapp[debug]: debug log 
 
logly.verbose( 'verbose log' );
// stdout: myapp[verbose]: verbose log 
 
logly.log( 'standard log' );
// stdout: myapp: standard log 
 
logly.warn( 'warning log' );
// stderr: myapp[warn]: warning log 
 
logly.error( 'error log' );
// stderr: myapp[error]: error log 
 
logly.stdout( 'stdout log' );
// stdout: stdout log 
// *above does not include 'myapp' 
 
logly.stderr( 'stderr log' );
// stderr: stderr log 
// *above does not include 'myapp' 

logly also accepts functions as input; this is primarily to conditionally produce a debug output of complex something if in debug mode, for example:

var options = { debug: true, output: "some.file" }
// dump options in debug mode 
logly.debug( function() {
  for ( var i = 0; i < options.length; i++ ) {
    logly.debug( '[OPTION] ' + option + "" + options[ option ] );
  }
});
// stdout: myapp[debug]: [OPTION] debug: true 
// stdout: myapp[debug]: [OPTION] output: some.file 

If you want color then you can enable it (by default color is disabled):

logly.options( { color : true } );

You can also use color or colour functions (maintained for backward compatibility):

logly.color(true);
logly.colour(true);

You can include a date prefix as well:

logly.options( { date : true } );
logly.log( 'with date' );
// stdout: Wed Aug 22 2012 21:22:52 GMT-0500 (CDT) myapp: with date 

ISO8601 format is also available:

logly.options( { date : 'iso' } ); // or 'ISO8601', 'iso8601', 'ISO' 
logly.log( 'with iso date' );
// stdout: 2012-08-23T02:26:14.841Z myapp: with iso date 

You can do string processing:

var processors = [];
processors.push( function( input ) {
    return input.replace(/\n/g, ' '); // replace newlines with spaces 
});
logly.options( { processors: processors } );
logly.log( 'some\nnewlines\nhere\nand\nthere');
// stdout: logly: some newlines here and there 

You can pass in the above options all together:

var processors = [];
processors.push( function( input ) {
    return input.replace(/\n/g, ' ');
});
logly.options( { colour : true, date : 'iso' , processors: processors } );