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 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. 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.
Used to provide a default answer to this question.
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.
The ERb template of the question to be asked.
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.
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.
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.
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
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 #convert. If given, a block is
yielded the new Question object to allow custom
initialization.
# File lib/highline/question.rb, line 32 def initialize( question, answer_type ) # initialize instance data @question = String(question).dup @answer_type = answer_type @completion = @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
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.
# File lib/highline/question.rb, line 217 def answer_or_default( answer_string ) if answer_string.length == 0 and not @default.nil? @default else answer_string 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.
# File lib/highline/question.rb, line 230 def build_responses(message_source = answer_type, new_hash_wins = false) append_default if [::String, Symbol].include? default.class choice_error_str_func = lambda do message_source.is_a?(Array) ? '[' + message_source.map { |s| "#{s}" }.join(', ') + ']' : message_source.inspect end old_hash = @responses new_hash = { :ambiguous_completion => "Ambiguous choice. Please choose one of " + choice_error_str_func.call + '.', :ask_on_error => "? ", :invalid_type => "You must enter a valid #{message_source}.", :no_completion => "You must choose one of " + choice_error_str_func.call + '.', :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})." } @responses = new_hash_wins ? old_hash.merge(new_hash) : new_hash.merge(old_hash) 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
.
# File lib/highline/question.rb, line 276 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
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 317 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
Returns an English explanation of the current range settings.
# File lib/highline/question.rb, line 351 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
Returns first_answer, which will be unset following this call.
# File lib/highline/question.rb, line 367 def first_answer( ) @first_answer ensure @first_answer = nil end
Returns true if first_answer is set.
# File lib/highline/question.rb, line 374 def first_answer?( ) not @first_answer.nil? 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 384 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
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.
# File lib/highline/question.rb, line 409 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
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 431 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
Stringifies the question to be asked.
# File lib/highline/question.rb, line 444 def to_s @question 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 455 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
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 468 def append_default( ) if @question =~ /([\t ]+)\Z/ @question << "|#{@default}|#{$1}" elsif @question == "" @question << "|#{@default}| " elsif @question[-1, 1] == "\n" @question[-2, 0] = " |#{@default}|" else @question << " |#{@default}|" end end