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
Used to control range checks for answer.
The answer, set by HighLine#ask
The type that will be used to convert this answer.
Used to control range checks for answer.
Used to control character case processing for the answer to this question. See #change_case for acceptable settings.
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.
For Auto-completion
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.
Used to provide a default answer to this question.
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
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)))
.
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).
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.
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.
The glob pattern used to limit file selection when File or Pathname is specified as an
answer_type. Initially set to "*"
.
If set, answer must pass an include?() check on this object.
Allows you to set a character limit for input.
WARNING: This option forces a character by character read.
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.
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.
The ERb template of the question to be asked.
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.
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.
Used to control whitespace processing for the answer to this question. See #remove_whitespace for acceptable settings.
Public Class Methods
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 ::new @return [Question]
# File lib/highline/question.rb, line 34 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
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 #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 51 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
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 248 def answer_or_default(answer_string) return default if answer_string.empty? && default answer_string end
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 575 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
Called late in the initialization process to build intelligent responses based on the details of this Question object. Also used by HighLine::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 262 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
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 281 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
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 326 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
Run {#in_range?} and raise an error if not succesful
# File lib/highline/question.rb, line 372 def check_range raise NotInRangeQuestionError unless in_range? end
Try to auto complete answer_string @param answer_string [String] @return [String]
# File lib/highline/question.rb, line 379 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
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 552 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
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 367 def convert AnswerConverter.new(self).convert end
# File lib/highline/question.rb, line 271 def default_responses_hash { ask_on_error: "? ", mismatch: "Your entries didn't match." } end
Returns an English explanation of the current range settings.
# File lib/highline/question.rb, line 389 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
# File lib/highline/question.rb, line 300 def final_response(error) response = final_responses[error] if response.respond_to?(:call) response.call(answer) else response end end
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 296 def final_responses @internal_responses.merge(@user_responses) end
Returns first_answer, which will be unset following this call.
# File lib/highline/question.rb, line 405 def first_answer @first_answer ensure @first_answer = nil end
Returns true if first_answer is set.
# File lib/highline/question.rb, line 412 def first_answer? true if @first_answer end
Convert to String, remove whitespace and change case when necessary @param answer_string [String] @return [String] converted String
# File lib/highline/question.rb, line 470 def format_answer(answer_string) answer_string = String(answer_string) answer_string = remove_whitespace(answer_string) change_case(answer_string) end
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 594 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
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 524 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
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 544 def get_response_or_default(highline) self.answer = answer_or_default(get_response(highline)) end
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 422 def in_range? (!above || answer > above) && (!below || answer < below) && (!@in || @in.include?(answer)) end
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 449 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
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 231 def responses @user_responses end
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 481 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
@param highline [HighLine] context @return [void]
# File lib/highline/question.rb, line 585 def show_question(highline) highline.say(self) end
Stringifies the template to be asked.
# File lib/highline/question.rb, line 494 def to_s template end
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 505 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
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 614 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
# File lib/highline/question.rb, line 631 def choice_error_str(message_source) if message_source.is_a? Array "[" + message_source.join(", ") + "]" else message_source.inspect end end