Class HighLine::Question
In: lib/highline/question.rb
Parent: Object

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.

Methods

answer_or_default   build_responses   change_case   convert   expected_range   first_answer   first_answer?   in_range?   new   remove_whitespace   selection   to_str   valid_answer?  

Classes and Modules

Class HighLine::Question::NoAutoCompleteMatch

Attributes

above  [RW]  Used to control range checks for answer.
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 and may not work correctly if STDIN is redirected.) 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.

confirm  [RW]  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.
default  [RW]  Used to provide a default answer to this question.
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 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).

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.
question  [RW]  The ERb template of the question to be asked.
readline  [RW]  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.

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

Public Class methods

new( question, answer_type ) {|self if block_given?| ...}

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 recongnized by Question.convert(). If given, a block is yeilded the new Question object to allow custom initializaion.

Public Instance methods

answer_or_default( answer_string )

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

build_responses( )

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

change_case( answer_string )

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.

convert( answer_string )

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().
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.

expected_range( )

Returns a english explination of the current range settings.

first_answer( )

Returns first_answer, which will be unset following this call.

first_answer?( )

Returns true if first_answer is set.

in_range?( answer_object )

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.

remove_whitespace( answer_string )

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.

selection( )

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.

to_str( )

Stringifies the question to be asked.

valid_answer?( answer_string )

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.

[Validate]