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/Crystal 0.31

module Colorize

Overview

With Colorize you can change the fore- and background colors and text decorations when rendering text on terminals supporting ANSI escape codes. It adds the colorize method to Object and thus all classes as its main interface, which calls to_s and surrounds it with the necessary escape codes when it comes to obtaining a string representation of the object.

Its first argument changes the foreground color:

require "colorize"

"foo".colorize(:green)
100.colorize(:red)
[1, 2, 3].colorize(:blue)

There are alternative ways to change the foreground color:

require "colorize"

"foo".colorize.fore(:green)
"foo".colorize.green

To change the background color, the following methods are available:

require "colorize"

"foo".colorize.back(:green)
"foo".colorize.on(:green)
"foo".colorize.on_green

You can also pass an RGB color to colorize:

require "colorize"

"foo".colorize(Colorize::ColorRGB.new(0, 255, 255)) # => "foo" in aqua

Or an 8-bit color:

require "colorize"

"foo".colorize(Colorize::Color256.new(208)) # => "foo" in orange

It's also possible to change the text decoration:

require "colorize"

"foo".colorize.mode(:underline)
"foo".colorize.underline

The colorize method returns a Colorize::Object instance, which allows chaining methods together:

require "colorize"

"foo".colorize.fore(:yellow).back(:blue).mode(:underline)

With the toggle method you can temporarily disable adding the escape codes. Settings of the instance are preserved however and can be turned back on later:

require "colorize"

"foo".colorize(:red).toggle(false)              # => "foo" without color
"foo".colorize(:red).toggle(false).toggle(true) # => "foo" in red

The color :default will just leave the object as it is (but it's an Colorize::Object(String) then). That's handy in for example conditions:

require "colorize"

"foo".colorize(some_bool ? :green : :default)

Available colors are:

:default
:black
:red
:green
:yellow
:blue
:magenta
:cyan
:light_gray
:dark_gray
:light_red
:light_green
:light_yellow
:light_blue
:light_magenta
:light_cyan
:white

Available text decorations are:

:bold
:bright
:dim
:underline
:blink
:reverse
:hidden

Defined in:

colorize.cr:110
colorize.cr:159

Class Method Summary

Class Method Detail

def self.enabled=(enabled : Bool)Source

If this value is true, Colorize::Object is enabled by default. But if this value is false, Colorize::Object is disabled.

The default value is true.

require "colorize"

Colorize.enabled = true
"hello".colorize.red.to_s # => "\e[31mhello\e[0m"

Colorize.enabled = false
"hello".colorize.red.to_s # => "hello"

def self.enabled? : BoolSource

If this value is true, Colorize::Object is enabled by default. But if this value is false, Colorize::Object is disabled.

The default value is true.

require "colorize"

Colorize.enabled = true
"hello".colorize.red.to_s # => "\e[31mhello\e[0m"

Colorize.enabled = false
"hello".colorize.red.to_s # => "hello"

def self.on_tty_only!Source

Makes Colorize.enabled true if and only if both of STDOUT.tty? and STDERR.tty? are true.

def self.reset(io = STDOUT)Source

© 2012–2019 Manas Technology Solutions.
Licensed under the Apache License, Version 2.0.
https://crystal-lang.org/api/0.31.1/Colorize.html