Output messages to the console.
See the log lib source for more information.
Grunt output should look consistent, and maybe even pretty. As such, there is a plethora of logging methods, and a few useful patterns. All of the methods that actually log something are chainable.
Note: all methods available under grunt.verbose
work exactly like grunt.log
methods, but only log if the --verbose
command-line option was specified.
Log the specified msg
string, with no trailing newline.
grunt.log.write(msg)
Log the specified msg
string, with trailing newline.
grunt.log.writeln([msg])
If msg
string is omitted, logs ERROR
in red, otherwise logs >> msg
, with trailing newline.
grunt.log.error([msg])
Log an error with grunt.log.error
, wrapping text to 80 columns using grunt.log.wraptext
.
grunt.log.errorlns(msg)
If msg
string is omitted, logs OK
in green, otherwise logs >> msg
, with trailing newline.
grunt.log.ok([msg])
Log an ok message with grunt.log.ok
, wrapping text to 80 columns using grunt.log.wraptext
.
grunt.log.oklns(msg)
Log the specified msg
string in bold, with trailing newline.
grunt.log.subhead(msg)
Log a list of obj
properties (good for debugging flags).
grunt.log.writeflags(obj, prefix)
Logs a debugging message, but only if the --debug
command-line option was specified.
grunt.log.debug(msg)
All logging methods available under grunt.verbose
work exactly like their grunt.log
counterparts, but only log if the --verbose
command-line option was specified. There is also a "notverbose" counterpart available at both grunt.log.notverbose
and grunt.log.verbose.or
. In fact, the .or
property can be used on both verbose
and notverbose
to effectively toggle between the two.
This object contains all methods of grunt.log
but only logs if the --verbose
command-line option was specified.
grunt.verbose
This object contains all methods of grunt.log
but only logs if the --verbose
command-line option was not specified.
grunt.verbose.or
These methods don't actually log, they just return strings that can be used in other methods.
Returns a comma-separated list of arr
array items.
grunt.log.wordlist(arr [, options])
The options
object has these possible properties, and default values:
var options = {
// The separator string (can be colored).
separator: ', ',
// The array item color (specify false to not colorize).
color: 'cyan',
};
Removes all color information from a string, making it suitable for testing .length
or perhaps logging to a file.
grunt.log.uncolor(str)
Wrap text
string to width
characters with \n
, ensuring that words are not split in the middle unless absolutely necessary.
grunt.log.wraptext(width, text)
Wrap texts
array of strings to columns widths
characters wide. A wrapper for the grunt.log.wraptext
method that can be used to generate output in columns.
grunt.log.table(widths, texts)
A common pattern is to only log when in --verbose
mode OR if an error occurs, like so:
grunt.registerTask('something', 'Do something interesting.', function(arg) {
var msg = 'Doing something...';
grunt.verbose.write(msg);
try {
doSomethingThatThrowsAnExceptionOnError(arg);
// Success!
grunt.verbose.ok();
} catch(e) {
// Something went wrong.
grunt.verbose.or.write(msg).error().error(e.message);
grunt.fail.warn('Something went wrong.');
}
});
An explanation of the above code:
grunt.verbose.write(msg);
logs the message (no newline), but only in--verbose
mode.grunt.verbose.ok();
logs OK in green, with a newline.grunt.verbose.or.write(msg).error().error(e.message);
does a few things:grunt.verbose.or.write(msg)
logs the message (no newline) if not in--verbose
mode, and returns thenotverbose
object..error()
logs ERROR in red, with a newline, and returns thenotverbose
object..error(e.message);
logs the actual error message (and returns thenotverbose
object).grunt.fail.warn('Something went wrong.');
logs a warning in bright yellow, exiting Grunt with exit code 1, unless--force
was specified.
Take a look at the grunt-contrib-* tasks source code for more examples.