Class: Chef::Knife::UI

Inherits:
Object show all
Extended by:
Forwardable
Defined in:
lib/chef/knife/core/ui.rb

Overview

Chef::Knife::UI

The User Interaction class used by knife.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stdout, stderr, stdin, config) ⇒ UI

Returns a new instance of UI


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# File 'lib/chef/knife/core/ui.rb', line 42

def initialize(stdout, stderr, stdin, config)
  @stdout, @stderr, @stdin, @config = stdout, stderr, stdin, config
  @presenter = Chef::Knife::Core::GenericPresenter.new(self, config)
end

Instance Attribute Details

#configObject (readonly)

Returns the value of attribute config


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# File 'lib/chef/knife/core/ui.rb', line 36

def config
  @config
end

#stderrObject (readonly)

Returns the value of attribute stderr


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# File 'lib/chef/knife/core/ui.rb', line 34

def stderr
  @stderr
end

#stdinObject (readonly)

Returns the value of attribute stdin


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# File 'lib/chef/knife/core/ui.rb', line 35

def stdin
  @stdin
end

#stdoutObject (readonly)

Returns the value of attribute stdout


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# File 'lib/chef/knife/core/ui.rb', line 33

def stdout
  @stdout
end

Instance Method Details

#ask(*args, &block) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 104

def ask(*args, &block)
  highline.ask(*args, &block)
end

#ask_question(question, opts = {}) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 125

def ask_question(question, opts={})
  question = question + "[#{opts[:default]}] " if opts[:default]

  if opts[:default] and config[:defaults]
    opts[:default]
  else
    stdout.print question
    a = stdin.readline.strip

    if opts[:default]
      a.empty? ? opts[:default] : a
    else
      a
    end
  end
end

#color(string, *colors) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 89

def color(string, *colors)
  if color?
    highline.color(string, *colors)
  else
    string
  end
end

#color?Boolean

Should colored output be used? For output to a terminal, this is determined by the value of `config`. When output is not to a terminal, colored output is never used

Returns:

  • (Boolean)

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# File 'lib/chef/knife/core/ui.rb', line 100

def color?
  Chef::Config[:color] && stdout.tty? && (RUBY_PLATFORM !~ /mswin|mingw32|windows/)
end

#confirm(question, append_instructions = true) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 194

def confirm(question, append_instructions=true)
  return true if config[:yes]

  stdout.print question
  stdout.print "? (Y/N) " if append_instructions
  answer = stdin.readline
  answer.chomp!
  case answer
  when "Y", "y"
    true
  when "N", "n"
    self.msg("You said no, so I'm done here.")
    exit 3
  else
    self.msg("I have no idea what to do with #{answer}")
    self.msg("Just say Y or N, please.")
    confirm(question)
  end
end

#edit_data(data, parse_output = true) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 146

def edit_data(data, parse_output=true)
  output = Chef::JSONCompat.to_json_pretty(data)

  if (!config[:no_editor])
    filename = "knife-edit-"
    0.upto(20) { filename += rand(9).to_s }
    filename << ".js"
    filename = File.join(Dir.tmpdir, filename)
    tf = File.open(filename, "w")
    tf.sync = true
    tf.puts output
    tf.close
    raise "Please set EDITOR environment variable" unless system("#{config[:editor]} #{tf.path}")
    tf = File.open(filename, "r")
    output = tf.gets(nil)
    tf.close
    File.unlink(filename)
  end

  parse_output ? Chef::JSONCompat.from_json(output) : output
end

#edit_object(klass, name) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 168

def edit_object(klass, name)
  object = klass.load(name)

  output = edit_data(object)

  # Only make the save if the user changed the object.
  #
  # Output JSON for the original (object) and edited (output), then parse
  # them without reconstituting the objects into real classes
  # (create_additions=false). Then, compare the resulting simple objects,
  # which will be Array/Hash/String/etc.
  #
  # We wouldn't have to do these shenanigans if all the editable objects
  # implemented to_hash, or if to_json against a hash returned a string
  # with stable key order.
  object_parsed_again = Chef::JSONCompat.from_json(Chef::JSONCompat.to_json(object), :create_additions => false)
  output_parsed_again = Chef::JSONCompat.from_json(Chef::JSONCompat.to_json(output), :create_additions => false)
  if object_parsed_again != output_parsed_again
    output.save
    self.msg("Saved #{output}")
  else
    self.msg("Object unchanged, not saving")
  end
  output(format_for_display(object)) if config[:print_after]
end

#err(message) ⇒ Object

Prints a msg to stderr. Used for warn, error, and fatal.


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# File 'lib/chef/knife/core/ui.rb', line 70

def err(message)
  stderr.puts message
end

#error(message) ⇒ Object

Print an error message


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# File 'lib/chef/knife/core/ui.rb', line 80

def error(message)
  err("#{color('ERROR:', :red, :bold)} #{message}")
end

#fatal(message) ⇒ Object

Print a message describing a fatal error.


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# File 'lib/chef/knife/core/ui.rb', line 85

def fatal(message)
  err("#{color('FATAL:', :red, :bold)} #{message}")
end

#highlineObject


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# File 'lib/chef/knife/core/ui.rb', line 54

def highline
  @highline ||= begin
    require 'highline'
    HighLine.new
  end
end

#interchange?Boolean

Determines if the output format is a data interchange format, i.e., JSON or YAML

Returns:

  • (Boolean)

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# File 'lib/chef/knife/core/ui.rb', line 121

def interchange?
  @presenter.interchange?
end

#list(*args) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 108

def list(*args)
  highline.list(*args)
end

#msg(message) ⇒ Object Also known as: info

Prints a message to stdout. Aliased as info for compatibility with the logger API.


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# File 'lib/chef/knife/core/ui.rb', line 63

def msg(message)
  stdout.puts message
end

#output(data) ⇒ Object

Formats data using the configured presenter and outputs the result via msg. Formatting can be customized by configuring a different presenter. See use_presenter


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# File 'lib/chef/knife/core/ui.rb', line 115

def output(data)
  msg @presenter.format(data)
end

#pretty_print(data) ⇒ Object


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# File 'lib/chef/knife/core/ui.rb', line 142

def pretty_print(data)
  stdout.puts data
end

#use_presenter(presenter_class) ⇒ Object

Creates a new presenter_class object and uses it to format structured data for display. By default, a Chef::Knife::Core::GenericPresenter object is used.


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# File 'lib/chef/knife/core/ui.rb', line 50

def use_presenter(presenter_class)
  @presenter = presenter_class.new(self, config)
end

#warn(message) ⇒ Object

Print a warning message


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# File 'lib/chef/knife/core/ui.rb', line 75

def warn(message)
  err("#{color('WARNING:', :yellow, :bold)} #{message}")
end