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Class: Gem::StreamUI

Relationships & Source Files
Namespace Children
Classes:
SilentDownloadReporter, SilentProgressReporter, SimpleProgressReporter, VerboseDownloadReporter, VerboseProgressReporter
Extension / Inclusion / Inheritance Descendants
Subclasses:
ConsoleUI, MockGemUi, SilentUI
Inherits: Object
Defined in: lib/rubygems/user_interaction.rb

Overview

StreamUI implements a simple stream based user interface.

Class Method Summary

Instance Attribute Summary

  • #errs readonly

    The error stream.

  • #ins readonly

    The input stream.

  • #outs readonly

    The output stream.

  • #tty? ⇒ Boolean readonly

    Returns true if TTY methods should be used on this StreamUI.

Instance Method Summary

Constructor Details

.new(in_stream, out_stream, err_stream = STDERR, usetty = true) ⇒ StreamUI

Creates a new StreamUI wrapping in_stream for user input, out_stream for standard output, err_stream for error output. If usetty is true then special operations (like asking for passwords) will use the TTY commands to disable character echo.

[ GitHub ] 

  


# File 'lib/rubygems/user_interaction.rb', line 197



def initialize(in_stream, out_stream, err_stream=STDERR, usetty=true)
  @ins = in_stream
  @outs = out_stream
  @errs = err_stream
  @usetty = usetty
end


  







Instance Attribute Details



  

    #errs   (readonly)
  



  

    

The error stream


  



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# File 'lib/rubygems/user_interaction.rb', line 189



attr_reader :errs


  








  

    #ins   (readonly)
  



  

    

The input stream


  



  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 179



attr_reader :ins


  








  

    #outs   (readonly)
  



  

    

The output stream


  



  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 184



attr_reader :outs


  








  

    #tty?  ⇒ Boolean  (readonly)
  



  

    

Returns true if TTY methods should be used on this StreamUI.


  





  


  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 207



def tty?
  if RUBY_VERSION < '1.9.3' and RUBY_PLATFORM =~ /mingw|mswin/ then
    @usetty
  else
    @usetty && @ins.tty?
  end
end


  







Instance Method Details



  

    #_gets_noecho  
  

  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 325



def _gets_noecho
  require_io_console
  if IO.method_defined?(:noecho) then
    @ins.noecho {@ins.gets}
  elsif Gem.win_platform?
    require "Win32API"
    password = ''

    while char = Win32API.new("crtdll", "_getch", [ ], "L").Call do
      break if char == 10 || char == 13 # received carriage return or newline
      if char == 127 || char == 8 # backspace and delete
        password.slice!(-1, 1)
      else
        password << char.chr
      end
    end
    password
  else
    system "stty -echo"
    begin
      @ins.gets
    ensure
      system "stty echo"
    end
  end
end


  








  

    #alert(statement, question = nil)  
  



  

    

Display an informational alert.  Will ask question if it is not nil.


  



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# File 'lib/rubygems/user_interaction.rb', line 362



def alert(statement, question=nil)
  @outs.puts "INFO:  #{statement}"
  ask(question) if question
end


  








  

    #alert_error(statement, question = nil)  
  



  

    

Display an error message in a location expected to get error messages. Will ask question if it is not nil.


  



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# File 'lib/rubygems/user_interaction.rb', line 379



def alert_error(statement, question=nil)
  @errs.puts "ERROR:  #{statement}"
  ask(question) if question
end


  








  

    #alert_warning(statement, question = nil)  
  



  

    

Display a warning on stderr.  Will ask question if it is not nil.


  



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# File 'lib/rubygems/user_interaction.rb', line 370



def alert_warning(statement, question=nil)
  @errs.puts "WARNING:  #{statement}"
  ask(question) if question
end


  








  

    #ask(question)  
  



  

    

Ask a question.  Returns an answer if connected to a tty, nil otherwise.


  



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# File 'lib/rubygems/user_interaction.rb', line 289



def ask(question)
  return nil if not tty?

  @outs.print(question + "  ")
  @outs.flush

  result = @ins.gets
  result.chomp! if result
  result
end


  








  

    #ask_for_password(question)  
  



  

    

Ask for a password. Does not echo response to terminal.


  



  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 303



def ask_for_password(question)
  return nil if not tty?

  @outs.print(question, "  ")
  @outs.flush

  password = _gets_noecho
  @outs.puts
  password.chomp! if password
  password
end


  








  

    #ask_yes_no(question, default = nil)  
  



  

    

Ask a question.  Returns a true for yes, false for no.  If not connected to a tty, raises an exception if default is nil, otherwise returns default.


  



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# File 'lib/rubygems/user_interaction.rb', line 253



def ask_yes_no(question, default=nil)
  unless tty? then
    if default.nil? then
      raise Gem::OperationNotSupportedError,
            "Not connected to a tty and no default specified"
    else
      return default
    end
  end

  default_answer = case default
                   when nil
                     'yn'
                   when true
                     'Yn'
                   else
                     'yN'
                   end

  result = nil

  while result.nil? do
    result = case ask "#{question} [#{default_answer}]"
             when /^y/i then true
             when /^n/i then false
             when /^$/  then default
             else            nil
             end
  end

  return result
end


  








  

    #backtrace(exception)  
  



  

    

Prints a formatted backtrace to the errors stream if backtraces are enabled.


  



  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 219



def backtrace exception
  return unless Gem.configuration.backtrace

  @errs.puts "\t#{exception.backtrace.join "\n\t"}"
end


  








  

    #choose_from_list(question, list)  
  



  

    

Choose from a list of options.  question is a prompt displayed above the list.  list is a list of option strings.  Returns the pair [option_name, option_index].


  



  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 230



def choose_from_list(question, list)
  @outs.puts question

  list.each_with_index do |item, index|
    @outs.puts " #{index+1}. #{item}"
  end

  @outs.print "> "
  @outs.flush

  result = @ins.gets

  return nil, nil unless result

  result = result.strip.to_i - 1
  return list[result], result
end


  








  

    #close  
  

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# File 'lib/rubygems/user_interaction.rb', line 400



def close
end


  








  

    #debug(statement)  
  



  

    

Display a debug message on the same location as error messages.


  



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# File 'lib/rubygems/user_interaction.rb', line 387



def debug(statement)
  @errs.puts statement
end


  








  

    #download_reporter(*args)  
  



  

    

Return a download reporter object chosen from the current verbosity


  



  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 539



def download_reporter(*args)
  case Gem.configuration.verbose
  when nil, false
    SilentDownloadReporter.new(@outs, *args)
  else
    VerboseDownloadReporter.new(@outs, *args)
  end
end


  








  

    #progress_reporter(*args)  
  



  

    

Return a progress reporter object chosen from the current verbosity.


  



  [ GitHub ]


  

  


# File 'lib/rubygems/user_interaction.rb', line 406



def progress_reporter(*args)
  case Gem.configuration.verbose
  when nil, false
    SilentProgressReporter.new(@outs, *args)
  when true
    SimpleProgressReporter.new(@outs, *args)
  else
    VerboseProgressReporter.new(@outs, *args)
  end
end


  








  

    #require_io_console  
  

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# File 'lib/rubygems/user_interaction.rb', line 315



def require_io_console
  @require_io_console ||= begin
    begin
      require 'io/console'
    rescue LoadError
    end
    true
  end
end


  








  

    #say(statement = "")  
  



  

    

Display a statement.


  



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# File 'lib/rubygems/user_interaction.rb', line 355



def say(statement="")
  @outs.puts statement
end


  








  

    #terminate_interaction(status = 0)  
  



  

    

Terminate the application with exit code status, running any exit handlers that might have been defined.


  





  
Raises:





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# File 'lib/rubygems/user_interaction.rb', line 395



def terminate_interaction(status = 0)
  close
  raise Gem::SystemExitException, status
end