Class: Stannum::Attribute

Inherits:
Object
  • Object
show all
Includes:
Support::Optional
Defined in:
lib/stannum/attribute.rb

Overview

Data object representing an attribute on an entity.

Defined Under Namespace

Classes: Builder

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Support::Optional

#optional?, #required?, resolve

Constructor Details

#initialize(name:, options:, type:) ⇒ Attribute

Returns a new instance of Attribute.

Parameters:

  • name (String, Symbol) —

    The name of the attribute. Converted to a String.

  • options (Hash, nil) —

    Options for the attribute. Converted to a Hash with Symbol keys. Defaults to an empty Hash.

  • type (Class, Module, String) —

    The type of the attribute. Can be a Class, a Module, or the name of a class or module.

Options Hash (options:):

  • :default (Object) —

    The default value for the attribute. Defaults to nil.

  • :primary_key (Boolean) —

    true if the attribute represents the primary key for the entity; otherwise false. Defaults to false.



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# File 'lib/stannum/attribute.rb', line 72

def initialize(name:, options:, type:)
  validate_name(name)
  validate_options(options)
  validate_type(type)

  @name    = name.to_s
  @options = tools.hash_tools.convert_keys_to_symbols(options || {})
  @options = resolve_required_option(**@options)

  @type, @resolved_type = resolve_type(type)
end

Instance Attribute Details

#name ⇒ String (readonly)

Returns the name of the attribute.

Returns:

  • (String) —

    the name of the attribute.



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# File 'lib/stannum/attribute.rb', line 85

def name
  @name
end

#options ⇒ Hash (readonly)

Returns the attribute options.

Returns:

  • (Hash) —

    the attribute options.



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# File 'lib/stannum/attribute.rb', line 88

def options
  @options
end

#type ⇒ String (readonly)

Returns the name of the attribute type Class or Module.

Returns:

  • (String) —

    the name of the attribute type Class or Module.



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# File 'lib/stannum/attribute.rb', line 91

def type
  @type
end

Instance Method Details

#association_name ⇒ String

Returns the name of the association if the attribute is a foreign key; otherwise false.

Returns:

  • (String) —

    the name of the association if the attribute is a foreign key; otherwise false.



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# File 'lib/stannum/attribute.rb', line 95

def association_name
  @options[:association_name]
end

#default ⇒ Object

Returns the default value for the attribute, if any.

Returns:

  • (Object) —

    the default value for the attribute, if any.



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# File 'lib/stannum/attribute.rb', line 100

def default
  @options[:default]
end

#default? ⇒ Boolean

Returns true if the attribute has a default value; otherwise false.

Returns:

  • (Boolean) —

    true if the attribute has a default value; otherwise false.



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# File 'lib/stannum/attribute.rb', line 106

def default?
  !@options[:default].nil?
end

#default_value_for(context) ⇒ Object

Returns the value of the default attribute for the given context object, if any.

Parameters:

  • context (Object) —

    the context object used to determinet the default value.

Returns:

  • (Object) —

    the value of the default attribute for the given context object, if any.



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# File 'lib/stannum/attribute.rb', line 115

def default_value_for(context)
  return default unless default.is_a?(Proc)

  default.arity.zero? ? default.call : default.call(context)
end

#foreign_key? ⇒ Boolean

Returns true if the attribute represents the foreign key for an association; otherwise false.

Returns:

  • (Boolean) —

    true if the attribute represents the foreign key for an association; otherwise false.



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# File 'lib/stannum/attribute.rb', line 123

def foreign_key?
  !!@options[:foreign_key]
end

#primary_key? ⇒ Boolean

Returns true if the attribute represents the primary key for the entity; otherwise false.

Returns:

  • (Boolean) —

    true if the attribute represents the primary key for the entity; otherwise false.



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# File 'lib/stannum/attribute.rb', line 129

def primary_key?
  !!@options[:primary_key]
end

#reader_name ⇒ Symbol

Returns the name of the reader method for the attribute.

Returns:

  • (Symbol) —

    the name of the reader method for the attribute.



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# File 'lib/stannum/attribute.rb', line 134

def reader_name
  @reader_name ||= name.intern
end

#resolved_type ⇒ Module

Returns the type of the attribute.

Returns:

  • (Module) —

    the type of the attribute.



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# File 'lib/stannum/attribute.rb', line 139

def resolved_type
  return @resolved_type if @resolved_type

  @resolved_type = Object.const_get(type)

  unless @resolved_type.is_a?(Module)
    raise NameError, "constant #{type} is not a Class or Module"
  end

  @resolved_type
end

#writer_name ⇒ Symbol

Returns the name of the writer method for the attribute.

Returns:

  • (Symbol) —

    the name of the writer method for the attribute.



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# File 'lib/stannum/attribute.rb', line 152

def writer_name
  @writer_name ||= :"#{name}="
end