Class: ActiveRecord::Attribute

Inherits:
Object
  • Object
show all
Defined in:
lib/active_record/attribute.rb,
lib/active_record/attribute/user_provided_default.rb

Overview

:nodoc:

Direct Known Subclasses

Relation::QueryAttribute

Defined Under Namespace

Classes: UserProvidedDefault

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(name, value_before_type_cast, type, original_attribute = nil) ⇒ Attribute

This method should not be called directly. Use #from_database or #from_user



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# File 'lib/active_record/attribute.rb', line 29

def initialize(name, value_before_type_cast, type, original_attribute = nil)
  @name = name
  @value_before_type_cast = value_before_type_cast
  @type = type
  @original_attribute = original_attribute
end

Instance Attribute Details

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/active_record/attribute.rb', line 25

def name
  @name
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



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# File 'lib/active_record/attribute.rb', line 25

def type
  @type
end

#value_before_type_cast ⇒ Object (readonly)

Returns the value of attribute value_before_type_cast.



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# File 'lib/active_record/attribute.rb', line 25

def value_before_type_cast
  @value_before_type_cast
end

Class Method Details

.from_database(name, value, type) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 4

def from_database(name, value, type)
  FromDatabase.new(name, value, type)
end

.from_user(name, value, type, original_attribute = nil) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 8

def from_user(name, value, type, original_attribute = nil)
  FromUser.new(name, value, type, original_attribute)
end

.null(name) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 16

def null(name)
  Null.new(name)
end

.uninitialized(name, type) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 20

def uninitialized(name, type)
  Uninitialized.new(name, type)
end

.with_cast_value(name, value, type) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 12

def with_cast_value(name, value, type)
  WithCastValue.new(name, value, type)
end

Instance Method Details

#==(other) ⇒ Object Also known as: eql? 



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# File 'lib/active_record/attribute.rb', line 103

def ==(other)
  self.class == other.class &&
    name == other.name &&
    value_before_type_cast == other.value_before_type_cast &&
    type == other.type
end

#came_from_user? ⇒ Boolean

Returns:

  • (Boolean) 


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

def came_from_user?
  false
end

#changed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/attribute.rb', line 54

def changed?
  changed_from_assignment? || changed_in_place?
end

#changed_in_place? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/attribute.rb', line 58

def changed_in_place?
  has_been_read? && type.changed_in_place?(original_value_for_database, value)
end

#encode_with(coder) ⇒ Object 



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

def encode_with(coder)
  coder["name"] = name
  coder["value_before_type_cast"] = value_before_type_cast if value_before_type_cast
  coder["type"] = type if type
  coder["original_attribute"] = original_attribute if original_attribute
  coder["value"] = value if defined?(@value)
end

#forgetting_assignment ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 62

def forgetting_assignment
  with_value_from_database(value_for_database)
end

#has_been_read? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/active_record/attribute.rb', line 99

def has_been_read?
  defined?(@value)
end

#hash ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 111

def hash
  [self.class, name, value_before_type_cast, type].hash
end

#init_with(coder) ⇒ Object 



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

def init_with(coder)
  @name = coder["name"]
  @value_before_type_cast = coder["value_before_type_cast"]
  @type = coder["type"]
  @original_attribute = coder["original_attribute"]
  @value = coder["value"] if coder.map.key?("value")
end

#initialized? ⇒ Boolean

Returns:

  • (Boolean) 


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

def initialized?
  true
end

#original_value ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 42

def original_value
  if assigned?
    original_attribute.original_value
  else
    type_cast(value_before_type_cast)
  end
end

#type_cast ⇒ Object

Raises:

  • (NotImplementedError) 


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# File 'lib/active_record/attribute.rb', line 87

def type_cast(*)
  raise NotImplementedError
end

#value ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 36

def value
  # `defined?` is cheaper than `||=` when we get back falsy values
  @value = type_cast(value_before_type_cast) unless defined?(@value)
  @value
end

#value_for_database ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 50

def value_for_database
  type.serialize(value)
end

#with_cast_value(value) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 75

def with_cast_value(value)
  self.class.with_cast_value(name, value, type)
end

#with_type(type) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 79

def with_type(type)
  if changed_in_place?
    with_value_from_user(value).with_type(type)
  else
    self.class.new(name, value_before_type_cast, type, original_attribute)
  end
end

#with_value_from_database(value) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 71

def with_value_from_database(value)
  self.class.from_database(name, value, type)
end

#with_value_from_user(value) ⇒ Object 



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# File 'lib/active_record/attribute.rb', line 66

def with_value_from_user(value)
  type.assert_valid_value(value)
  self.class.from_user(name, value, type, original_attribute || self)
end