Class: Inquirer

Inherits:
Object
  • Object
show all
Defined in:
lib/esm/extension/inquirer.rb

Overview

A base class that allows for creating classes that can be asked questions. Very similar to ActiveSupport::StringInquirer and ArrayInquirer, except stricter See initializer

Instance Method Summary collapse

Constructor Details

#initialize(*predicates, default: nil) ⇒ Inquirer

Returns a new instance of Inquirer.

Examples:

Implementing StringInquirer

environment = Inquirer.new(:production, :staging, :test, :development)
environment.set(ENV["RAILS_ENV"] || :development)

environment.staging? #=> false
environment.development? #=> true
environment.predicate_does_not_exist? #=> undefined method predicate_does_not_exists? for Inquirer

Implementing ArrayInquirer

fruits = Inquirer.new(:apples, :oranges, :bananas, default: [:oranges, :bananas])

fruits.apples? #=> false
fruits.oranges? #=> true
fruits.bananas? #=> true
fruits.grapes? #=> undefined method grapes? for Inquirer

Parameters:

  • *predicates (Array<String>, Array<Symbol>) —

    The questions this class can be asked



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# File 'lib/esm/extension/inquirer.rb', line 27

def initialize(*predicates, default: nil)
  @predicates = predicates.map(&:to_sym)

  define_predicates

  if default
    default = [default] unless default.is_a?(Array)
    set(*default)
  end
end

Instance Method Details

#set(*predicates, unset: true) ⇒ Self

Sets the provided predicates to true

Parameters:

  • *predicates (Array<Symbol>) —

    Which predicates to set to true

  • unset (TrueClass, FalseClass, Array, Symbol) (defaults to: true) —

    Which predicates to unset FalseClass: Do nothing. TrueClass: Un-sets all other predicates. Default Array: Un-set the provided predicates Symbol: Un-set the provided predicate

Returns:

  • (Self) 


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# File 'lib/esm/extension/inquirer.rb', line 50

def set(*predicates, unset: true)
  predicates = predicates.map(&:to_sym)

  if (invalid_predicates = predicates - @predicates) && invalid_predicates.size > 0
    raise ArgumentError, "#{invalid_predicates} are not allowed as predicates for #{self.class.name}. Valid options: #{@predicates}"
  end

  # Unset
  case unset
  when true
    unset(*@predicates)
  when Array, Symbol
    unset = [unset] unless unset.is_a?(Array)
    unset(*unset)
  end

  # Set
  predicates.each do |predicate|
    instance_variable_set(:"@#{predicate}", true)
  end

  self
end

#to_a ⇒ Object 



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# File 'lib/esm/extension/inquirer.rb', line 97

def to_a
  to_h.select { |_predicate, enabled| enabled }.keys
end

#to_h ⇒ Object 



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# File 'lib/esm/extension/inquirer.rb', line 91

def to_h
  @predicates.index_with do |predicate|
    instance_variable_get(:"@#{predicate}")
  end
end

#to_s ⇒ Object 



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# File 'lib/esm/extension/inquirer.rb', line 101

def to_s
  enabled_predicates = to_a

  if enabled_predicates.size > 1
    enabled_predicates.to_s
  else
    enabled_predicates.first.to_s
  end
end

#unset(*predicates) ⇒ Self

Sets the provided predicates to false

Parameters:

  • *predicates (Array<Symbol>) —

    Which predicates to set to false

Returns:

  • (Self) 


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# File 'lib/esm/extension/inquirer.rb', line 81

def unset(*predicates)
  predicates.map(&:to_sym).each do |predicate|
    next if @predicates.exclude?(predicate)

    instance_variable_set(:"@#{predicate}", false)
  end

  self
end