class HighLine::Question

Question objects contain all the details of a single invocation of HighLine.ask(). The object is initialized by the parameters passed to HighLine.ask() and then queried to make sure each step of the input process is handled according to the users wishes.

Attributes

above[RW]

Used to control range checks for answer.

answer[RW]

The answer, set by HighLine#ask

answer_type[RW]

The type that will be used to convert this answer.

below[RW]

Used to control range checks for answer.

case[RW]

Used to control character case processing for the answer to this question. See HighLine::Question.change_case() for acceptable settings.

character[RW]

Can be set to true to use HighLine’s cross-platform character reader instead of fetching an entire line of input. (Note: HighLine’s character reader ONLY supports STDIN on Windows and Unix.) Can also be set to :getc to use that method on the input stream.

WARNING: The echo and overwrite attributes for a question are ignored when using the :getc method.

completion[RW]

For Auto-completion

confirm[RW]

Asks a yes or no confirmation question, to ensure a user knows what they have just agreed to. The confirm attribute can be set to : true : In this case the question will be, “Are you sure?”. Proc : The Proc is yielded the answer given. The Proc must

output a string which is then used as the confirm
question.

String : The String must use ERB syntax. The String is

evaluated with access to question and answer and
is then used as the confirm question.

When set to false or nil (the default), answers are not confirmed.

default[RW]

Used to provide a default answer to this question.

default_hint_show[RW]

Set it to a truthy or falsy value to enable or disable showing the default value hint between vertical bars (pipes) when asking the question. Defaults to true

directory[RW]

The directory from which a user will be allowed to select files, when File or Pathname is specified as an answer_type. Initially set to Pathname.new(File.expand_path(File.dirname($0))).

echo[RW]

Can be set to true or false to control whether or not input will be echoed back to the user. A setting of true will cause echo to match input, but any other true value will be treated as a String to echo for each character typed.

This requires HighLine’s character reader. See the character attribute for details.

Note: When using HighLine to manage echo on Unix based systems, we recommend installing the termios gem. Without it, it’s possible to type fast enough to have letters still show up (when reading character by character only).

first_answer[W]

When set to a non nil value, this will be tried as an answer to the question. If this answer passes validations, it will become the result without the user ever being prompted. Otherwise this value is discarded, and this Question is resolved as a normal call to HighLine.ask().

gather[RW]

When set, the user will be prompted for multiple answers which will be collected into an Array or Hash and returned as the final answer.

You can set gather to an Integer to have an Array of exactly that many answers collected, or a String/Regexp to match an end input which will not be returned in the Array.

Optionally gather can be set to a Hash. In this case, the question will be asked once for each key and the answers will be returned in a Hash, mapped by key. The @key variable is set before each question is evaluated, so you can use it in your question.

glob[RW]

The glob pattern used to limit file selection when File or Pathname is specified as an answer_type. Initially set to "*".

in[RW]

If set, answer must pass an include?() check on this object.

limit[RW]

Allows you to set a character limit for input.

WARNING: This option forces a character by character read.

overwrite[RW]

When set to true the question is asked, but output does not progress to the next line. The Cursor is moved back to the beginning of the question line and it is cleared so that all the contents of the line disappear from the screen.

readline[RW]

Use the Reline library to fetch input. This allows input editing as well as keeping a history. In addition, tab will auto-complete within an Array of choices or a file listing.

WARNING: This option is incompatible with all of HighLine’s character reading modes and it causes HighLine to ignore the specified input stream.

template[RW]

The ERb template of the question to be asked.

validate[RW]

If set to a Regexp, the answer must match (before type conversion). Can also be set to a Proc which will be called with the provided answer to validate with a true or false return. It’s possible to use a custom validator class. It must respond to ‘#valid?`. The result of `#inspect` will be used in error messages. See README.md for details.

verify_match[RW]

When set to true multiple entries will be collected according to the setting for gather, except they will be required to match each other. Multiple identical entries will return a single answer.

whitespace[RW]

Used to control whitespace processing for the answer to this question. See HighLine::Question.remove_whitespace() for acceptable settings.

Public Class Methods

build(template_or_question, answer_type = nil, &details) click to toggle source

If template_or_question is already a Question object just return it. If not, build it.

@param template_or_question [String, Question] what to ask @param answer_type [Class] to what class to convert the answer @param details to be passed to Question.new @return [Question]

# File lib/highline/question.rb, line 35
def self.build(template_or_question, answer_type = nil, &details)
  if template_or_question.is_a? Question
    template_or_question
  else
    Question.new(template_or_question, answer_type, &details)
  end
end
new(template, answer_type) { |self| ... } click to toggle source

Create an instance of HighLine::Question. Expects a template to ask (can be "") and an answer_type to convert the answer to. The answer_type parameter must be a type recognized by Question.convert(). If given, a block is yielded the new Question object to allow custom initialization.

@param template [String] any String @param answer_type [Class] the type the answer will be converted to it.

# File lib/highline/question.rb, line 52
def initialize(template, answer_type)
  # initialize instance data
  @template    = String(template).dup
  @answer_type = answer_type
  @completion  = @answer_type

  @echo         = true
  @default_hint_show = true
  @whitespace   = :strip
  @case         = nil
  @in           = nil
  @first_answer = nil
  @glob         = "*"
  @overwrite    = false
  @user_responses = {}
  @internal_responses = default_responses_hash
  @directory = Pathname.new(File.expand_path(File.dirname($PROGRAM_NAME)))

  # allow block to override settings
  yield self if block_given?

  # finalize responses based on settings
  build_responses
end

Public Instance Methods

answer_or_default(answer_string) click to toggle source

Returns the provided answer_string or the default answer for this Question if a default was set and the answer is empty.

@param answer_string [String] @return [String] the answer itself or a default message.

# File lib/highline/question.rb, line 249
def answer_or_default(answer_string)
  return default if answer_string.empty? && default
  answer_string
end
ask_on_error_msg() click to toggle source

Provides the String to be asked when at an error situation. It may be just the question itself (repeat on error). @return [self] if :ask_on_error on responses Hash is set to :question @return [String] if :ask_on_error on responses Hash is set to

something else
# File lib/highline/question.rb, line 576
def ask_on_error_msg
  if final_responses[:ask_on_error] == :question
    self
  elsif final_responses[:ask_on_error]
    final_responses[:ask_on_error]
  end
end
build_responses(message_source = answer_type) click to toggle source

Called late in the initialization process to build intelligent responses based on the details of this Question object. Also used by Menu#update_responses.

@return [Hash] responses Hash winner (new and old merge). @param message_source [Class] Array or String for example.

Same as {#answer_type}.
# File lib/highline/question.rb, line 263
def build_responses(message_source = answer_type)
  append_default_to_template if default_hint_show

  new_hash = build_responses_new_hash(message_source)
  # Update our internal responses with the new hash
  # generated from the message source
  @internal_responses = @internal_responses.merge(new_hash)
end
build_responses_new_hash(message_source) click to toggle source

When updating the responses hash, it generates the new one. @param message_source (see build_responses) @return [Hash] responses hash

# File lib/highline/question.rb, line 282
def build_responses_new_hash(message_source)
  { ambiguous_completion: "Ambiguous choice.  Please choose one of " +
    choice_error_str(message_source) + ".",
    invalid_type: "You must enter a valid #{message_source}.",
    no_completion: "You must choose one of " +
      choice_error_str(message_source) + ".",
    not_in_range: "Your answer isn't within the expected range " \
      "(#{expected_range}).",
    not_valid: "Your answer isn't valid (must match " \
      "#{validate.inspect})." }
end
change_case(answer_string) click to toggle source

Returns the provided answer_string after changing character case by the rules of this Question. Valid settings for whitespace are:

nil

Do not alter character case. (Default.)

:up

Calls upcase().

:upcase

Calls upcase().

:down

Calls downcase().

:downcase

Calls downcase().

:capitalize

Calls capitalize().

An unrecognized choice (like :none) is treated as nil.

@param answer_string [String] @return [String] upcased, downcased, capitalized

or unchanged answer String.
# File lib/highline/question.rb, line 327
def change_case(answer_string)
  if [:up, :upcase].include?(@case)
    answer_string.upcase
  elsif [:down, :downcase].include?(@case)
    answer_string.downcase
  elsif @case == :capitalize
    answer_string.capitalize
  else
    answer_string
  end
end
check_range() click to toggle source

Run {#in_range?} and raise an error if not succesful

# File lib/highline/question.rb, line 373
def check_range
  raise NotInRangeQuestionError unless in_range?
end
choices_complete(answer_string) click to toggle source

Try to auto complete answer_string @param answer_string [String] @return [String]

# File lib/highline/question.rb, line 380
def choices_complete(answer_string)
  # cheating, using OptionParser's Completion module
  choices = selection
  choices.extend(OptionParser::Completion)
  answer = choices.complete(answer_string)
  raise NoAutoCompleteMatch unless answer
  answer
end
confirm_question(highline) click to toggle source

Returns the String to be shown when asking for an answer confirmation. @param highline [HighLine] context @return [String] default “Are you sure?” if {#confirm} is true @return [String] {#confirm} rendered as a template if it is a String

# File lib/highline/question.rb, line 553
def confirm_question(highline)
  if confirm == true
    "Are you sure?  "
  elsif confirm.is_a?(Proc)
    confirm.call(answer)
  else
    # evaluate ERb under initial scope, so it will have
    # access to question and answer
    template = if ERB.instance_method(:initialize).parameters.assoc(:key) # Ruby 2.6+
      ERB.new(confirm, trim_mode: "%")
    else
      ERB.new(confirm, nil, "%")
    end
    template_renderer = TemplateRenderer.new(template, self, highline)
    template_renderer.render
  end
end
convert() click to toggle source

Transforms the given answer_string into the expected type for this Question. Currently supported conversions are:

[...]

Answer must be a member of the passed Array. Auto-completion is used to expand partial answers.

lambda {...}

Answer is passed to lambda for conversion.

Date

Date.parse() is called with answer.

DateTime

DateTime.parse() is called with answer.

File

The entered file name is auto-completed in terms of directory + glob, opened, and returned.

Float

Answer is converted with Kernel.Float().

Integer

Answer is converted with Kernel.Integer().

nil

Answer is left in String format. (Default.)

Pathname

Same as File, save that a Pathname object is returned.

String

Answer is converted with Kernel.String().

HighLine::String

Answer is converted with HighLine::String()

Regexp

Answer is fed to Regexp.new().

Symbol

The method to_sym() is called on answer and the result returned.

any other Class

The answer is passed on to Class.parse().

This method throws ArgumentError, if the conversion cannot be completed for any reason.

# File lib/highline/question.rb, line 368
def convert
  AnswerConverter.new(self).convert
end
default_responses_hash() click to toggle source
# File lib/highline/question.rb, line 272
def default_responses_hash
  {
    ask_on_error: "?  ",
    mismatch: "Your entries didn't match."
  }
end
expected_range() click to toggle source

Returns an English explanation of the current range settings.

# File lib/highline/question.rb, line 390
def expected_range
  expected = []

  expected << "above #{above}" if above
  expected << "below #{below}" if below
  expected << "included in #{@in.inspect}" if @in

  case expected.size
  when 0 then ""
  when 1 then expected.first
  when 2 then expected.join(" and ")
  else        expected[0..-2].join(", ") + ", and #{expected.last}"
  end
end
final_response(error) click to toggle source
# File lib/highline/question.rb, line 301
def final_response(error)
  response = final_responses[error]
  if response.respond_to?(:call)
    response.call(answer)
  else
    response
  end
end
final_responses() click to toggle source

This is the actual responses hash that gets used in determining output Notice that we give @user_responses precedence over the responses generated internally via build_response

# File lib/highline/question.rb, line 297
def final_responses
  @internal_responses.merge(@user_responses)
end
first_answer() click to toggle source

Returns first_answer, which will be unset following this call.

# File lib/highline/question.rb, line 406
def first_answer
  @first_answer
ensure
  @first_answer = nil
end
first_answer?() click to toggle source

Returns true if first_answer is set.

# File lib/highline/question.rb, line 413
def first_answer?
  true if @first_answer
end
format_answer(answer_string) click to toggle source

Convert to String, remove whitespace and change case when necessary @param answer_string [String] @return [String] converted String

# File lib/highline/question.rb, line 471
def format_answer(answer_string)
  answer_string = String(answer_string)
  answer_string = remove_whitespace(answer_string)
  change_case(answer_string)
end
get_echo_for_response(response) click to toggle source

Returns an echo string that is adequate for this Question settings. @param response [String] @return [String] the response itself if {#echo} is true. @return [String] echo character if {#echo} is truethy. Mainly a String. @return [String] empty string if {#echo} is falsy.

# File lib/highline/question.rb, line 595
def get_echo_for_response(response)
  # actually true, not only truethy value
  if echo == true
    response
  # any truethy value, probably a String
  elsif echo
    echo
  # any falsy value, false or nil
  else
    ""
  end
end
get_response(highline) click to toggle source

Return a line or character of input, as requested for this question. Character input will be returned as a single character String, not an Integer.

This question’s first_answer will be returned instead of input, if set.

Raises EOFError if input is exhausted.

@param highline [HighLine] context @return [String] a character or line

# File lib/highline/question.rb, line 525
def get_response(highline)
  return first_answer if first_answer?

  case character
  when :getc
    highline.get_response_getc_mode(self)
  when true
    highline.get_response_character_mode(self)
  else
    highline.get_response_line_mode(self)
  end
end
get_response_or_default(highline) click to toggle source

Uses {#get_response} but returns a default answer using {#answer_or_default} in case no answers was returned.

@param highline [HighLine] context @return [String]

# File lib/highline/question.rb, line 545
def get_response_or_default(highline)
  self.answer = answer_or_default(get_response(highline))
end
in_range?() click to toggle source

Returns true if the answer_object is greater than the above attribute, less than the below attribute and include?()ed in the in attribute. Otherwise, false is returned. Any nil attributes are not checked.

# File lib/highline/question.rb, line 423
def in_range?
  (!above || answer > above) &&
    (!below || answer < below) &&
    (!@in || @in.include?(answer))
end
remove_whitespace(answer_string) click to toggle source

Returns the provided answer_string after processing whitespace by the rules of this Question. Valid settings for whitespace are:

nil

Do not alter whitespace.

:strip

Calls strip(). (Default.)

:chomp

Calls chomp().

:collapse

Collapses all whitespace runs to a single space.

:strip_and_collapse

Calls strip(), then collapses all whitespace runs to a single space.

:chomp_and_collapse

Calls chomp(), then collapses all whitespace runs to a single space.

:remove

Removes all whitespace.

An unrecognized choice (like :none) is treated as nil.

This process is skipped for single character input.

@param answer_string [String] @return [String] answer string with whitespaces removed

# File lib/highline/question.rb, line 450
def remove_whitespace(answer_string)
  if !whitespace
    answer_string
  elsif [:strip, :chomp].include?(whitespace)
    answer_string.send(whitespace)
  elsif whitespace == :collapse
    answer_string.gsub(/\s+/, " ")
  elsif [:strip_and_collapse, :chomp_and_collapse].include?(whitespace)
    result = answer_string.send(whitespace.to_s[/^[a-z]+/])
    result.gsub(/\s+/, " ")
  elsif whitespace == :remove
    answer_string.gsub(/\s+/, "")
  else
    answer_string
  end
end
responses() click to toggle source

A Hash that stores the various responses used by HighLine to notify the user. The currently used responses and their purpose are as follows:

:ambiguous_completion

Used to notify the user of an ambiguous answer the auto-completion system cannot resolve.

:ask_on_error

This is the question that will be redisplayed to the user in the event of an error. Can be set to :question to repeat the original question.

:invalid_type

The error message shown when a type conversion fails.

:no_completion

Used to notify the user that their selection does not have a valid auto-completion match.

:not_in_range

Used to notify the user that a provided answer did not satisfy the range requirement tests.

:not_valid

The error message shown when validation checks fail.

# File lib/highline/question.rb, line 232
def responses
  @user_responses
end
selection() click to toggle source

Returns an Array of valid answers to this question. These answers are only known when answer_type is set to an Array of choices, File, or Pathname. Any other time, this method will return an empty Array.

# File lib/highline/question.rb, line 482
def selection
  if completion.is_a?(Array)
    completion
  elsif [File, Pathname].include?(completion)
    Dir[File.join(directory.to_s, glob)].map do |file|
      File.basename(file)
    end
  else
    []
  end
end
show_question(highline) click to toggle source

@param highline [HighLine] context @return [void]

# File lib/highline/question.rb, line 586
def show_question(highline)
  highline.say(self)
end
to_s() click to toggle source

Stringifies the template to be asked.

# File lib/highline/question.rb, line 495
def to_s
  template
end
valid_answer?() click to toggle source

Returns true if the provided answer_string is accepted by the validate attribute or false if it’s not.

It’s important to realize that an answer is validated after whitespace and case handling.

# File lib/highline/question.rb, line 506
def valid_answer?
  !validate ||
    (validate.is_a?(Regexp) && answer =~ validate) ||
    (validate.is_a?(Proc)   && validate[answer]) ||
    (validate.respond_to?(:valid?) && validate.valid?(answer))
end

Private Instance Methods

append_default_to_template() click to toggle source

Adds the default choice to the end of question between |...|. Trailing whitespace is preserved so the function of HighLine.say() is not affected.

# File lib/highline/question.rb, line 615
def append_default_to_template
  return unless default.respond_to? :to_s

  default_str = default.to_s
  return if default_str.empty?

  if template =~ /([\t ]+)\Z/
    template << "|#{default_str}|#{Regexp.last_match(1)}"
  elsif template == ""
    template << "|#{default_str}|  "
  elsif template[-1, 1] == "\n"
    template[-2, 0] = "  |#{default_str}|"
  else
    template << "  |#{default_str}|"
  end
end
choice_error_str(message_source) click to toggle source
# File lib/highline/question.rb, line 632
def choice_error_str(message_source)
  if message_source.is_a? Array
    "[" + message_source.join(", ") + "]"
  else
    message_source.inspect
  end
end