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Class: Gem::Command

Overview

Base class for all ::Gem commands. When creating a new gem command, define #initialize, #execute, #arguments, #defaults_str, #description and #usage (as appropriate). See the above mentioned methods for details.

A very good example to look at is Commands::ContentsCommand

Class Attribute Summary

Class Method Summary

Instance Attribute Summary

  • #defaults rw

    The default options for the command.

  • #program_name rw

    The name of the command for command-line invocation.

  • #summary rw

    A short description of the command.

  • #command readonly

    The name of the command.

  • #options readonly

    The options for the command.

DefaultUserInteraction - Included

Instance Method Summary

UserInteraction - Included

#alert

Displays an alert statement.

#alert_error

Displays an error statement to the error output location.

#alert_warning

Displays a warning statement to the warning output location.

#ask

Asks a question and returns the answer.

#ask_for_password

Asks for a password with a prompt

#ask_yes_no

Asks a yes or no question.

#choose_from_list

Asks the user to answer question with an answer from the given list.

#say

Displays the given statement on the standard output (or equivalent).

#terminate_interaction

Terminates the RubyGems process with the given exit_code

#verbose

Calls say with msg or the results of the block if really_verbose is true.

DefaultUserInteraction - Included

Constructor Details

.new(command, summary = nil, defaults = {}) ⇒ Command

Initializes a generic gem command named #command. #summary is a short description displayed in gem help commands. #defaults are the default options. Defaults should be mirrored in #defaults_str, unless there are none.

When defining a new command subclass, use add_option to add command-line switches.

Unhandled arguments (gem names, files, etc.) are left in options[:args].

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# File 'lib/rubygems/command.rb', line 118

def initialize(command, summary=nil, defaults={})
  @command = command
  @summary = summary
  @program_name = "gem #{command}"
  @defaults = defaults
  @options = defaults.dup
  @option_groups = Hash.new { |h,k| h[k] = [] }
  @parser = nil
  @when_invoked = nil
end

Class Attribute Details

.build_args (rw)

Arguments used when building gems

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# File 'lib/rubygems/command.rb', line 51

def self.build_args
  @build_args ||= []
end

.build_args=(value) (rw)

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# File 'lib/rubygems/command.rb', line 55

def self.build_args=(value)
  @build_args = value
end

.extra_args (rw)

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# File 'lib/rubygems/command.rb', line 67

def self.extra_args
  @extra_args ||= []
end

.extra_args=(value) (rw)

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# File 'lib/rubygems/command.rb', line 71

def self.extra_args=(value)
  case value
  when Array
    @extra_args = value
  when String
    @extra_args = value.split
  end
end

Class Method Details

.add_common_option(*args, &handler)

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# File 'lib/rubygems/command.rb', line 63

def self.add_common_option(*args, &handler)
  Gem::Command.common_options << [args, handler]
end

.add_specific_extra_args(cmd, args)

Add a list of extra arguments for the given command. args may be an array or a string to be split on white space.

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# File 'lib/rubygems/command.rb', line 92

def self.add_specific_extra_args(cmd,args)
  args = args.split(/\s+/) if args.kind_of? String
  specific_extra_args_hash[cmd] = args
end

.common_options

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# File 'lib/rubygems/command.rb', line 59

def self.common_options
  @common_options ||= []
end

.specific_extra_args(cmd)

Return an array of extra arguments for the command. The extra arguments come from the gem configuration file read at program startup.

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# File 'lib/rubygems/command.rb', line 84

def self.specific_extra_args(cmd)
  specific_extra_args_hash[cmd]
end

.specific_extra_args_hash

Accessor for the specific extra args hash (self initializing).

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# File 'lib/rubygems/command.rb', line 100

def self.specific_extra_args_hash
  @specific_extra_args_hash ||= Hash.new do |h,k|
    h[k] = Array.new
  end
end

Instance Attribute Details

#command (readonly)

The name of the command.

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# File 'lib/rubygems/command.rb', line 26

attr_reader :command

#defaults (rw)

The default options for the command.

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# File 'lib/rubygems/command.rb', line 36

attr_accessor :defaults

#options (readonly)

The options for the command.

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# File 'lib/rubygems/command.rb', line 31

attr_reader :options

#program_name (rw)

The name of the command for command-line invocation.

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# File 'lib/rubygems/command.rb', line 41

attr_accessor :program_name

#summary (rw)

A short description of the command.

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# File 'lib/rubygems/command.rb', line 46

attr_accessor :summary

Instance Method Details

#add_extra_args(args)

Adds extra args from ~/.gemrc

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# File 'lib/rubygems/command.rb', line 385

def add_extra_args(args)
  result = []

  s_extra = Gem::Command.specific_extra_args(@command)
  extra = Gem::Command.extra_args + s_extra

  until extra.empty? do
    ex = []
    ex << extra.shift
    ex << extra.shift if extra.first.to_s =~ /^[^-]/
    result << ex if handles?(ex)
  end

  result.flatten!
  result.concat(args)
  result
end

#add_option(*opts, &handler)

Add a command-line option and handler to the command.

See OptionParser#make_switch for an explanation of opts.

handler will be called with two values, the value of the argument and the options hash.

If the first argument of add_option is a Symbol, it's used to group options in output. See gem help list for an example.

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# File 'lib/rubygems/command.rb', line 335

def add_option(*opts, &handler) # :yields: value, options
  group_name = Symbol === opts.first ? opts.shift : :options

  @option_groups[group_name] << [opts, handler]
end

#add_parser_run_info(title, content) (private)

Adds a section with title and content to the parser help view. Used for adding command arguments and default arguments.

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# File 'lib/rubygems/command.rb', line 436

def add_parser_run_info title, content
  return if content.empty?

  @parser.separator nil
  @parser.separator "  #{title}:"
  content.split(/\n/).each do |line|
    @parser.separator "    #{line}"
  end
end

#arguments

Override to provide details of the arguments a command takes. It should return a left-justified string, one argument per line.

For example:

def usage
  "#{program_name} FILE [FILE ...]"
end

def arguments
  "FILE          name of file to find"
end
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# File 'lib/rubygems/command.rb', line 245

def arguments
  ""
end

#begins?(long, short) ⇒ Boolean

True if long begins with the characters from short.

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# File 'lib/rubygems/command.rb', line 132

def begins?(long, short)
  return false if short.nil?
  long[0, short.length] == short
end

#configure_options(header, option_list) (private)

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# File 'lib/rubygems/command.rb', line 482

def configure_options(header, option_list)
  return if option_list.nil? or option_list.empty?

  header = header.to_s.empty? ? '' : "#{header} "
  @parser.separator "  #{header}Options:"

  option_list.each do |args, handler|
    args.select { |arg| arg =~ /^-/ }
    @parser.on(*args) do |value|
      handler.call(value, @options)
    end
  end

  @parser.separator ''
end

#create_option_parser (private)

Creates an option parser and fills it in with the help info for the command.

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# File 'lib/rubygems/command.rb', line 468

def create_option_parser
  @parser = OptionParser.new

  add_parser_options

  @parser.separator nil
  configure_options "Common", Gem::Command.common_options

  add_parser_run_info "Arguments", arguments
  add_parser_summary
  add_parser_description
  add_parser_run_info "Defaults", defaults_str
end

#defaults_str

Override to display the default values of the command options. (similar to #arguments, but displays the default values).

For example:

def defaults_str
  --no-gems-first --no-all
end
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# File 'lib/rubygems/command.rb', line 259

def defaults_str
  ""
end

#description

Override to display a longer description of what this command does.

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# File 'lib/rubygems/command.rb', line 266

def description
  nil
end

#execute

Override to provide command handling.

#options will be filled in with your parsed options, unparsed options will be left in options[:args].

See also: #get_all_gem_names, #get_one_gem_name, #get_one_optional_argument

Raises:

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# File 'lib/rubygems/command.rb', line 146

def execute
  raise Gem::Exception, "generic command has no actions"
end

#get_all_gem_names

Get all gem names from the command line.

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# File 'lib/rubygems/command.rb', line 176

def get_all_gem_names
  args = options[:args]

  if args.nil? or args.empty? then
    raise Gem::CommandLineError,
          "Please specify at least one gem name (e.g. gem build GEMNAME)"
  end

  args.select { |arg| arg !~ /^-/ }
end

#get_all_gem_names_and_versions

Get all [gem, version] from the command line.

An argument in the form gem:ver is pull apart into the gen name and version, respectively.

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# File 'lib/rubygems/command.rb', line 192

def get_all_gem_names_and_versions
  get_all_gem_names.map do |name|
    if /\A(.*):(#{Gem::Requirement::PATTERN_RAW})\z/ =~ name
      [$1, $2]
    else
      [name]
    end
  end
end

#get_one_gem_name

Get a single gem name from the command line. Fail if there is no gem name or if there is more than one gem name given.

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# File 'lib/rubygems/command.rb', line 206

def get_one_gem_name
  args = options[:args]

  if args.nil? or args.empty? then
    raise Gem::CommandLineError,
          "Please specify a gem name on the command line (e.g. gem build GEMNAME)"
  end

  if args.size > 1 then
    raise Gem::CommandLineError,
          "Too many gem names (#{args.join(', ')}); please specify only one"
  end

  args.first
end

#get_one_optional_argument

Get a single optional argument from the command line. If more than one argument is given, return only the first. Return nil if none are given.

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# File 'lib/rubygems/command.rb', line 226

def get_one_optional_argument
  args = options[:args] || []
  args.first
end

#handle_options(args)

Handle the given list of arguments by parsing them and recording the results.

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# File 'lib/rubygems/command.rb', line 375

def handle_options(args)
  args = add_extra_args(args)
  @options = Marshal.load Marshal.dump @defaults # deep copy
  parser.parse!(args)
  @options[:args] = args
end

#handles?(args) ⇒ Boolean

True if the command handles the given argument list.

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

def handles?(args)
  begin
    parser.parse!(args.dup)
    return true
  rescue
    return false
  end
end

#invoke(*args)

Invoke the command with the given list of arguments.

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# File 'lib/rubygems/command.rb', line 290

def invoke(*args)
  invoke_with_build_args args, nil
end

#invoke_with_build_args(args, build_args)

Invoke the command with the given list of normal arguments and additional build arguments.

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# File 'lib/rubygems/command.rb', line 298

def invoke_with_build_args(args, build_args)
  handle_options args

  options[:build_args] = build_args

  if options[:help] then
    show_help
  elsif @when_invoked then
    @when_invoked.call options
  else
    execute
  end
end

#merge_options(new_options)

Merge a set of command options with the set of default options (without modifying the default option hash).

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# File 'lib/rubygems/command.rb', line 354

def merge_options(new_options)
  @options = @defaults.clone
  new_options.each do |k,v| @options[k] = v end
end

#parser (private)

Create on demand parser.

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# File 'lib/rubygems/command.rb', line 459

def parser
  create_option_parser if @parser.nil?
  @parser
end

#remove_option(name)

Remove previously defined command-line argument name.

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# File 'lib/rubygems/command.rb', line 344

def remove_option(name)
  @option_groups.each do |_, option_list|
    option_list.reject! { |args, _| args.any? { |x| x =~ /^#{name}/ } }
  end
end

#show_help

Display the help message for the command.

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# File 'lib/rubygems/command.rb', line 282

def show_help
  parser.program_name = usage
  say parser
end

#show_lookup_failure(gem_name, version, errors, domain)

Display to the user that a gem couldn't be found and reasons why

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# File 'lib/rubygems/command.rb', line 155

def show_lookup_failure(gem_name, version, errors, domain)
  if errors and !errors.empty?
    msg = "Could not find a valid gem '#{gem_name}' (#{version}), here is why:\n".dup
    errors.each { |x| msg << "          #{x.wordy}\n" }
    alert_error msg
  else
    alert_error "Could not find a valid gem '#{gem_name}' (#{version}) in any repository"
  end

  unless domain == :local then # HACK
    suggestions = Gem::SpecFetcher.fetcher.suggest_gems_from_name gem_name

    unless suggestions.empty?
      alert_error "Possible alternatives: #{suggestions.join(", ")}"
    end
  end
end

#usage

Override to display the usage for an individual gem command.

The text “[options]” is automatically appended to the usage text.

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# File 'lib/rubygems/command.rb', line 275

def usage
  program_name
end

#when_invoked(&block)

Call the given block when invoked.

Normal command invocations just executes the #execute method of the command. Specifying an invocation block allows the test methods to override the normal action of a command to determine that it has been invoked correctly.

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# File 'lib/rubygems/command.rb', line 320

def when_invoked(&block)
  @when_invoked = block
end

#wrap(text, width) (private)

Wraps text to width

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# File 'lib/rubygems/command.rb', line 501

def wrap(text, width) # :doc:
  text.gsub(/(.{1,#{width}})( +|$\n?)|(.{1,#{width}})/, "\\1\\3\n")
end