Module: Inform::Prototypical

Included in:
Ephemeral::Object
Defined in:
lib/story_teller/prototype.rb

Overview

The Inform::Prototypical module

Constant Summary collapse

MethodWriterTemplate = 
'%<method_name>s='.freeze
VariableTemplate = 
'@%<property>s'.freeze
MethodBooleanOrBangPattern = 
%r{([\?!]+)$}.freeze
MethodWriterPattern = 
%r{=$}.freeze
LinkPattern = 
%r{.+_to$}.freeze
AccessorMethodTemplate = 
%(
def %<accessor>s(*args)
  args.empty? ? self._get(__method__) : self._set(__method__, *args)
end
).freeze
WriterMethodTemplate = 
%(
def %<writer>s(value)
  self._assign(__method__.to_s.chop.to_sym, value)
end
).freeze
MISSING_PROPERTIES_MESSAGE = 
'Missing properties attribute for: ' \
'%<identity>s'.freeze

Instance Method Summary collapse

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object

rubocop: disable Style/MissingRespondToMissing



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# File 'lib/story_teller/prototype.rb', line 132

def method_missing(method, *args, &block)
  stack = Thread.current[:prototypical_method_missing_stack] ||= []
  frame = [object_id, method]

  if stack.include?(frame)
    raise NoMethodError, "Aborting Prototypical missing method " \
      "resolution #{self.class}##{method} on #{inspect}"
  end

  stack << frame
  attempt_resolution(method, *args, &block)
ensure
  stack&.pop
end

Instance Method Details

#&(property, *args) ⇒ Object

This method tries to access or write values given by *args to the property using an accessor or writer method, and failing that, will invoke the prototype method, which dynamically defines an accessor or writer method on the receiver for future ease of access. rubocop: disable Metrics/AbcSize rubocop: disable Metrics/BlockNesting rubocop: disable Metrics/CyclomaticComplexity rubocop: disable Metrics/MethodLength rubocop: disable Metrics/PerceivedComplexity



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# File 'lib/story_teller/prototype.rb', line 63

def &(property, *args)
  return nil if property.nil?
  return super unless property.is_a?(Symbol) || property.is_a?(String)
  return nil if property.respond_to?(:empty?) && property.empty?
  property, sub_property = property.to_s.split('.').map(&:to_sym)
  if !args.empty?
    setter = format(MethodWriterTemplate, method_name: property)
    if !sub_property.nil?
      value = self.send(property)
      if value.object?
        value.&(sub_property, *args)
      elsif value.respond_to?(:key?)
        value[sub_property] = (args.length > 1 ? args : args.first)
        self.send(setter, value)
      else
        self.send(setter, *args)
      end
    elsif self.respond_to?(property) && args.length == self.method(property).arity
      self.send(property, *args)
    elsif self.respond_to?(setter) && args.length == self.method(setter).arity
      self.send(setter, *args)
    elsif !Kernel.methods.include?(property)
      self.send(property, *args)
    else
      self.prototype(property, *args)
    end
  elsif !sub_property.nil?
    value = self.send(property)
    if value.object?
      value.&(sub_property, *args)
    elsif value.respond_to?(property)
      value.send(property)
    elsif value.respond_to?(:key?)
      value[sub_property]
    else
      value
    end
  elsif self.respond_to?(property)
    self.send(property)
  elsif (self.properties.respond_to?(:key?) && self.properties.key?(property)) ||
      (self.respond_to?(:_key?) && self._key?(property))
    self.prototype(property)
  else
    return nil
  end
end

#_assign(key, value) ⇒ Object

rubocop: disable Metrics/AbcSize rubocop: disable Metrics/CyclomaticComplexity rubocop: disable Metrics/MethodLength rubocop: disable Metrics/PerceivedComplexity



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# File 'lib/story_teller/prototype.rb', line 394

def _assign(key, value)
  raise "The key parameter must be a symbol" unless key.is_a? Symbol
  result = nil
  if value.object?
    result = self._set_object(key, value) if self.respond_to?(:_set_object)
  elsif key_refers_to_link?(key) && (linked_object = object_for_link_value(value))
    result = set_link_property(key, linked_object)
  elsif value.nil? && self.respond_to?(:_key?) && self._key?(key)
    result = self._unset_object(key) if self.respond_to?(:_unset_object)
  elsif value.nil? && self.properties.key?(key)
    self.will_change_column(:properties) if self.respond_to?(:will_change_column)
    self.properties.delete(property_key_for(key))
    self.save_changes if self.respond_to?(:save_changes)
  else
    self.will_change_column(:properties) if self.respond_to?(:will_change_column)
    self.properties[key] = value
    self.save_changes if self.respond_to?(:save_changes)
  end
  result || self.properties.dup[property_key_for(key)]
end

#_get(key) ⇒ Object 



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# File 'lib/story_teller/prototype.rb', line 346

def _get(key)
  result = nil
  result = self._get_object(key) if self.respond_to?(:_key?) && self._key?(key)
  return result unless result.nil?

  resolve_link_property(key) || self.properties.dup[property_key_for(key)]
end

#_set(key, *values) ⇒ Object

rubocop: disable Metrics/AbcSize rubocop: disable Metrics/CyclomaticComplexity rubocop: disable Metrics/MethodLength rubocop: disable Metrics/PerceivedComplexity



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# File 'lib/story_teller/prototype.rb', line 358

def _set(key, *values)
  raise "The key parameter must be a symbol" unless key.is_a? Symbol
  raise "The values parameter may not be empty" if values.empty?
  result = nil
  if values.first.object?
    result = self._set_object(key, values.first) if respond_to? :_set_object
  elsif key_refers_to_link?(key) && (linked_object = object_for_link_value(values.first))
    result = set_link_property(key, linked_object)
  elsif values.first.nil? && self.respond_to?(:_key?) && self._key?(key)
    result = self._unset_object(key) if self.respond_to?(:_unset_object)
  elsif values.first.nil?
    self.will_change_column(:properties) if self.respond_to?(:will_change_column)
    self.properties.delete(property_key_for(key))
    self.save_changes if self.respond_to?(:save_changes)
  elsif values.length > 1
    self.will_change_column(:properties) if self.respond_to?(:will_change_column)
    self.properties[key] = []
    self.properties[key].concat(values)
    values.clear
    self.save_changes if self.respond_to?(:save_changes)
  else
    self.will_change_column(:properties) if self.respond_to?(:will_change_column)
    self.properties[key] = values.first
    self.save_changes if self.respond_to?(:save_changes)
  end
  result || self.properties.dup[property_key_for(key)]
end

#accessor_and_writer(key) ⇒ Object

TODO: Remove (2026-04-28) def respond_to_missing?(method, include_all=false)

m = method.to_s
return false if m =~ /\?$/
mname = m =~ /\=$/ ? m.chop : m
property = mname.intern
StoryTeller::Engine.invocation_properties.include? property

end



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# File 'lib/story_teller/prototype.rb', line 211

def accessor_and_writer(key)
  return [key.to_s.chop, key] if MethodWriterPattern.match?(key)
  [key, format(MethodWriterTemplate, method_name: key)]
end

#attempt_resolution(method, *args, &block) ⇒ Object

rubocop: disable Metrics/AbcSize rubocop: disable Metrics/CyclomaticComplexity rubocop: disable Metrics/MethodLength rubocop: disable Metrics/PerceivedComplexity

Raises:

  • (NoMethodError) 


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# File 'lib/story_teller/prototype.rb', line 152

def attempt_resolution(method, *args, &block)
  raise NoMethodError, "undefined method `#{method}' for #{self}" if method == :to_ary
  m = method.to_s
  raise NoMethodError, "undefined method `#{method}' for #{self}" if MethodBooleanOrBangPattern.match?(m)
  mname = MethodWriterPattern.match?(m) ? m.chop : m
  property = mname.to_sym
  variable = format(VariableTemplate, property: property).to_sym
  event = context_event

  library = respond_to?(:inflib, true) ? inflib : nil
  object_properties = respond_to?(:properties, true) ? properties : nil

  if MethodWriterPattern.match?(m) || (LinkPattern.match?(m) && !args.empty?)
    if !event.nil? && StoryTeller::Engine.invocation_properties.include?(property)
      event.send(method, *args, &block)
    elsif library&.library_method?(method)
      library.send(method, *args, &block)
    else
      self.prototype(method, *args, &block)
    end
  elsif !event.nil? && StoryTeller::Engine.invocation_properties.include?(property)
    result = event.send(method, *args, &block)
    log.debug("Value for event #{event}.#{method} is: #{result || 'nil'}") if defined? DEBUG
    result
  elsif library&.library_method?(method)
    library.send(method, *args, &block)
  elsif library.respond_to?(method) && StoryTeller::Engine.invocation_properties.include?(property)
    library.send(method, *args, &block)
  elsif library&.instance_variable_get(variable) || library&.instance_variables&.include?(variable)
    library.instance_variable_get(variable)
  elsif property_defined?(object_properties, property) ||
      (respond_to?(:_key?) && _key?(property)) ||
      !args.empty?
    self.prototype(method, *args, &block)
  # TODO: Remove (2026-04-28)
  # Experiment with supporting only property setting for those
  # declared in StoryTeller::Library.declarations.properties.
  # elsif (properties.respond_to?(:key?) && properties.key?(property)) ||
  #     (respond_to?(:_key?) && _key?(property)) ||
  #     StoryTeller::Library.declarations.properties.key?(property)
  #   self.prototype(method, *args, &block)
  else
    raise NoMethodError, "undefined method `#{method}' for #{self}"
  end
end

#constant_for_link_value(value) ⇒ Object 



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# File 'lib/story_teller/prototype.rb', line 291

def constant_for_link_value(value)
  names = value.to_s.split('::').reject(&:empty?)
  return nil if names.empty?

  names.inject(::Object) do |scope, name|
    return nil unless scope.const_defined?(name)

    scope.const_get(name)
  end
rescue NameError
  nil
end

#context_event ⇒ Object 



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# File 'lib/story_teller/prototype.rb', line 26

def context_event
  Thread.current[:event]
end

#declared_property?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/story_teller/prototype.rb', line 324

def declared_property?(key)
  return false unless defined?(StoryTeller::Library)
  return false unless StoryTeller::Library.respond_to?(:declarations)

  declarations = StoryTeller::Library.declarations
  properties = declarations.properties if declarations.respond_to?(:properties)
  return false unless properties.respond_to?(:key?)

  properties.key?(key.to_sym) || properties.key?(key.to_s)
rescue StandardError
  false
end

#ensure_properties_attribute! ⇒ Object

Raises:

  • (StandardError) 


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# File 'lib/story_teller/prototype.rb', line 307

def ensure_properties_attribute!
  return unless self.properties.nil?
  raise StandardError, format(MISSING_PROPERTIES_MESSAGE, identity: self.identity)
end

#instance_variables_map ⇒ Object 



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# File 'lib/story_teller/prototype.rb', line 30

def instance_variables_map
  instance_variables.each_with_object({}) do |key, memo|
    memo[key] = instance_variable_get(key)
  end
end

#key_refers_to_link?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/story_teller/prototype.rb', line 318

def key_refers_to_link?(key)
  return false unless LinkPattern.match?(key.to_s)

  declared_property?(key)
end

#object_for_link_value(value) ⇒ Object

rubocop: enable Metrics/CyclomaticComplexity



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# File 'lib/story_teller/prototype.rb', line 281

def object_for_link_value(value)
  return value if value.respond_to?(:object?) && value.object?
  return nil unless value.is_a?(Symbol) || value.is_a?(String)

  object = constant_for_link_value(value)
  return object if object.respond_to?(:object?) && object.object?

  nil
end

#property_defined?(object_properties, property) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/story_teller/prototype.rb', line 312

def property_defined?(object_properties, property)
  return false unless object_properties.respond_to?(:key?)

  object_properties.key?(property) || object_properties.key?(property.to_s)
end

#property_key_for(key) ⇒ Object 



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# File 'lib/story_teller/prototype.rb', line 337

def property_key_for(key)
  return key if self.properties.key?(key)

  string_key = key.to_s
  return string_key if self.properties.key?(string_key)

  nil
end

#prototype(key, *args, &block) ⇒ Object

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# File 'lib/story_teller/prototype.rb', line 230

def prototype(key, *args, &block)
  ensure_properties_attribute!
  accessor, writer = accessor_and_writer(key)
  link_result = nil

  if key_refers_to_link?(key)
    self.will_change_column(:properties) if self.respond_to?(:will_change_column)

    if args.empty?
      link_result = resolve_link_property(key)
    else
      linked_object = object_for_link_value(args.first)
      if linked_object.nil?
        self.properties[key] = args.first
      else
        link_result = set_link_property(key, linked_object)
      end
    end
  end

  accessor = format(AccessorMethodTemplate, accessor: accessor)
  self.instance_eval(accessor, __FILE__, __LINE__)
  writer = format(WriterMethodTemplate, writer: writer)
  self.instance_eval(writer, __FILE__, __LINE__)

  return link_result unless link_result.nil?

  self.send(key, *args, &block)
end

#resolve_link_property(key) ⇒ Object

rubocop: disable Metrics/CyclomaticComplexity



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# File 'lib/story_teller/prototype.rb', line 263

def resolve_link_property(key)
  return nil unless key_refers_to_link?(key)

  linked_object = self._get_object(key) if self.respond_to?(:_key?) &&
    self._key?(key) &&
    self.respond_to?(:_get_object)
  return linked_object unless linked_object.nil?

  property_key = property_key_for(key)
  return nil if property_key.nil?

  linked_object = object_for_link_value(self.properties[property_key])
  return nil if linked_object.nil?

  set_link_property(key, linked_object, property_key: property_key)
end

#set_link_property(key, object, property_key: property_key_for(key)) ⇒ Object

rubocop: enable Metrics/AbcSize rubocop: enable Metrics/CyclomaticComplexity rubocop: enable Metrics/MethodLength rubocop: enable Metrics/PerceivedComplexity



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# File 'lib/story_teller/prototype.rb', line 419

def set_link_property(key, object, property_key: property_key_for(key))
  result = if self.respond_to?(:_set_object)
    self._set_object(key, object)
  elsif self.respond_to?(:link)
    self.link(key, object)
    object
  end
  self.properties.delete(property_key) unless property_key.nil?
  self.will_change_column(:properties) if self.respond_to?(:will_change_column)
  self.save_changes if self.respond_to?(:save_changes)
  result || object
end

#string?(key) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/story_teller/prototype.rb', line 45

def string?(key)
  v = self.&key
  return false if v.nil?
  v.respond_to?(:to_s) && !v.to_s.empty?
end

#values ⇒ Object 



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# File 'lib/story_teller/prototype.rb', line 36

def values
  result = super
  return result if result && result != __method__
  raise NoMethodError, "undefined method `#{__method__}' for #{self}"
rescue StandardError => e
  log.warn "Unexpected error invoking super(Inform::Prototypical#values): #{e.message}"
  instance_variables_map
end

#|(property, *args) ⇒ Object

This method attempts to get a value if it exists. If no value is already set on the receiver, any given arguments will be set on the receiver for future access.



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# File 'lib/story_teller/prototype.rb', line 118

def |(property, *args)
  return nil if property.nil?
  return super unless property.respond_to?(:to_s)
  return nil if property.to_s.empty?
  v = self.&property
  v || send(property, *args)
end