Class: HighLine::Question

Inherits:
Object show all
Defined in:
lib/highline/question.rb

Overview

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.

Direct Known Subclasses

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Defined Under Namespace

Classes: NoAutoCompleteMatch

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(question, answer_type) {|_self| ... } ⇒ Question

Create an instance of HighLine::Question. Expects a question 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 yeilded the new Question object to allow custom initializaion.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/highline/question.rb', line 32

def initialize( question, answer_type )
  # initialize instance data
  @question    = question.dup
  @answer_type = answer_type

  @character    = nil
  @limit        = nil
  @echo         = true
  @readline     = false
  @whitespace   = :strip
  @case         = nil
  @default      = nil
  @validate     = nil
  @above        = nil
  @below        = nil
  @in           = nil
  @confirm      = nil
  @gather       = false
  @verify_match = false
  @first_answer = nil
  @directory    = Pathname.new(File.expand_path(File.dirname($0)))
  @glob         = "*"
  @responses    = Hash.new
  @overwrite    = false

  # allow block to override settings
  yield self if block_given?

  # finalize responses based on settings
  build_responses
end

Instance Attribute Details

#above ⇒ Object

Used to control range checks for answer.



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# File 'lib/highline/question.rb', line 128

def above
  @above
end

#answer_type ⇒ Object

The type that will be used to convert this answer.



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# File 'lib/highline/question.rb', line 67

def answer_type
  @answer_type
end

#below ⇒ Object

Used to control range checks for answer.



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# File 'lib/highline/question.rb', line 128

def below
  @below
end

#case ⇒ Object

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



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# File 'lib/highline/question.rb', line 118

def case
  @case
end

#character ⇒ Object

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.



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# File 'lib/highline/question.rb', line 77

def character
  @character
end

#confirm ⇒ Object

Asks a yes or no confirmation question, to ensure a user knows what they have just agreed to. If set to true the question will be, “Are you sure? ” Any other true value for this attribute is assumed to be the question to ask. When false or nil (the default), answers are not confirmed.



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# File 'lib/highline/question.rb', line 138

def confirm
  @confirm
end

#default ⇒ Object

Used to provide a default answer to this question.



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# File 'lib/highline/question.rb', line 120

def default
  @default
end

#directory ⇒ Object

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))).



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# File 'lib/highline/question.rb', line 171

def directory
  @directory
end

#echo ⇒ Object

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 to 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).



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# File 'lib/highline/question.rb', line 98

def echo
  @echo
end

#first_answer ⇒ Object

Returns first_answer, which will be unset following this call.



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# File 'lib/highline/question.rb', line 359

def first_answer( )
  @first_answer
ensure
  @first_answer = nil
end

#gather ⇒ Object

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.



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# File 'lib/highline/question.rb', line 152

def gather
  @gather
end

#glob ⇒ Object

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



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# File 'lib/highline/question.rb', line 176

def glob
  @glob
end

#in ⇒ Object

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



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# File 'lib/highline/question.rb', line 130

def in
  @in
end

#limit ⇒ Object

Allows you to set a character limit for input.

WARNING: This option forces a character by character read.



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# File 'lib/highline/question.rb', line 83

def limit
  @limit
end

#overwrite ⇒ Object

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.



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# File 'lib/highline/question.rb', line 208

def overwrite
  @overwrite
end

#question ⇒ Object

The ERb template of the question to be asked.



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# File 'lib/highline/question.rb', line 65

def question
  @question
end

#readline ⇒ Object

Use the Readline 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.



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# File 'lib/highline/question.rb', line 108

def readline
  @readline
end

#responses ⇒ Object (readonly)

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.



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# File 'lib/highline/question.rb', line 201

def responses
  @responses
end

#validate ⇒ Object

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.



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# File 'lib/highline/question.rb', line 126

def validate
  @validate
end

#verify_match ⇒ Object

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.



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# File 'lib/highline/question.rb', line 158

def verify_match
  @verify_match
end

#whitespace ⇒ Object

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



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# File 'lib/highline/question.rb', line 113

def whitespace
  @whitespace
end

Instance Method Details

#answer_or_default(answer_string) ⇒ Object

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



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# File 'lib/highline/question.rb', line 214

def answer_or_default( answer_string )
  if answer_string.length == 0 and not @default.nil?
    @default
  else
    answer_string
  end
end

#build_responses ⇒ Object

Called late in the initialization process to build intelligent responses based on the details of this Question object.



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# File 'lib/highline/question.rb', line 226

def build_responses(  )
  ### WARNING:  This code is quasi-duplicated in     ###
  ### Menu.update_responses().  Check there too when ###
  ### making changes!                                ###
  append_default unless default.nil?
  @responses = { :ambiguous_completion =>
                   "Ambiguous choice.  " +
                   "Please choose one of #{@answer_type.inspect}.",
                 :ask_on_error         =>
                   "?  ",
                 :invalid_type         =>
                   "You must enter a valid #{@answer_type}.",
                 :no_completion        =>
                   "You must choose one of " +
                   "#{@answer_type.inspect}.",
                 :not_in_range         =>
                   "Your answer isn't within the expected range " +
                   "(#{expected_range}).",
                 :mismatch             =>
                   "Your entries didn't match.",
                 :not_valid            =>
                   "Your answer isn't valid (must match " +
                   "#{@validate.inspect})." }.merge(@responses)
  ### WARNING:  This code is quasi-duplicated in     ###
  ### Menu.update_responses().  Check there too when ###
  ### making changes!                                ###
end

#change_case(answer_string) ⇒ Object

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.



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# File 'lib/highline/question.rb', line 268

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

#convert(answer_string) ⇒ Object

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.



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# File 'lib/highline/question.rb', line 309

def convert( answer_string )
  if @answer_type.nil?
    answer_string
  elsif [::String, HighLine::String].include?(@answer_type)
    HighLine::String(answer_string)
  elsif [Float, Integer, String].include?(@answer_type)
    Kernel.send(@answer_type.to_s.to_sym, answer_string)
  elsif @answer_type == Symbol
    answer_string.to_sym
  elsif @answer_type == Regexp
    Regexp.new(answer_string)
  elsif @answer_type.is_a?(Array) or [File, Pathname].include?(@answer_type)
    # cheating, using OptionParser's Completion module
    choices = selection
    choices.extend(OptionParser::Completion)
    answer = choices.complete(answer_string)
    if answer.nil?
      raise NoAutoCompleteMatch
    end
    if @answer_type.is_a?(Array)
      answer.last
    elsif @answer_type == File
      File.open(File.join(@directory.to_s, answer.last))
    else
      Pathname.new(File.join(@directory.to_s, answer.last))
    end
  elsif [Date, DateTime].include?(@answer_type) or @answer_type.is_a?(Class)
    @answer_type.parse(answer_string)
  elsif @answer_type.is_a?(Proc)
    @answer_type[answer_string]
  end
end

#expected_range ⇒ Object

Returns an English explanation of the current range settings.



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# File 'lib/highline/question.rb', line 343

def expected_range(  )
  expected = [ ]

  expected << "above #{@above}" unless @above.nil?
  expected << "below #{@below}" unless @below.nil?
  expected << "included in #{@in.inspect}" unless @in.nil?

  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

#first_answer? ⇒ Boolean

Returns true if first_answer is set.

Returns:

  • (Boolean) 


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# File 'lib/highline/question.rb', line 366

def first_answer?( )
  not @first_answer.nil?
end

#in_range?(answer_object) ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/highline/question.rb', line 376

def in_range?( answer_object )
  (@above.nil? or answer_object > @above) and
  (@below.nil? or answer_object < @below) and
  (@in.nil? or @in.include?(answer_object))
end

#remove_whitespace(answer_string) ⇒ Object

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 whitspace runs to a single space.

:strip_and_collapse

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

:chomp_and_collapse

Calls chomp(), then collapses all whitspace 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.



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# File 'lib/highline/question.rb', line 401

def remove_whitespace( answer_string )
  if @whitespace.nil?
    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

#selection ⇒ Object

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.



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# File 'lib/highline/question.rb', line 423

def selection(  )
  if @answer_type.is_a?(Array)
    @answer_type
  elsif [File, Pathname].include?(@answer_type)
    Dir[File.join(@directory.to_s, @glob)].map do |file|
      File.basename(file)
    end
  else
    [ ]
  end      
end

#to_str ⇒ Object

Stringifies the question to be asked.



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# File 'lib/highline/question.rb', line 436

def to_str(  )
  @question
end

#valid_answer?(answer_string) ⇒ Boolean

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.

Returns:

  • (Boolean) 


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# File 'lib/highline/question.rb', line 447

def valid_answer?( answer_string )
  @validate.nil? or 
  (@validate.is_a?(Regexp) and answer_string =~ @validate) or
  (@validate.is_a?(Proc)   and @validate[answer_string])
end