Module: ActiveRecord::Core

Extended by:
ActiveSupport::Concern
Includes:
ActiveModel::Access
Included in:
Base
Defined in:
lib/active_record/core.rb

Overview

Active Record Core

Defined Under Namespace

Modules: ClassMethods

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#strict_loading_mode ⇒ Object (readonly)

Returns the value of attribute strict_loading_mode.



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# File 'lib/active_record/core.rb', line 729

def strict_loading_mode
  @strict_loading_mode
end

Instance Method Details

#<=>(other_object) ⇒ Object

Allows sort on objects



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# File 'lib/active_record/core.rb', line 665

def <=>(other_object)
  if other_object.is_a?(self.class)
    to_key <=> other_object.to_key
  else
    super
  end
end

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

Returns true if comparison_object is the same exact object, or comparison_object is of the same type and self has an ID and it is equal to comparison_object.id.

Note that new records are different from any other record by definition, unless the other record is the receiver itself. Besides, if you fetch existing records with select and leave the ID out, you’re on your own, this predicate will return false.

Note also that destroying a record preserves its ID in the model instance, so deleted models are still comparable.



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# File 'lib/active_record/core.rb', line 631

def ==(comparison_object)
  super ||
    comparison_object.instance_of?(self.class) &&
    primary_key_values_present? &&
    comparison_object.id == id
end

#blank? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/active_record/core.rb', line 677

def blank? # :nodoc:
  false
end

#connection_handler ⇒ Object 



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# File 'lib/active_record/core.rb', line 768

def connection_handler
  self.class.connection_handler
end

#encode_with(coder) ⇒ Object

Populate coder with attributes about this record that should be serialized. The structure of coder defined in this method is guaranteed to match the structure of coder passed to the #init_with method.

Example:

class Post < ActiveRecord::Base
end
coder = {}
Post.new.encode_with(coder)
coder # => {"attributes" => {"id" => nil, ... }}



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# File 'lib/active_record/core.rb', line 587

def encode_with(coder)
  self.class.yaml_encoder.encode(@attributes, coder)
  coder["new_record"] = new_record?
  coder["active_record_yaml_version"] = 2
end

#freeze ⇒ Object

Clone and freeze the attributes hash such that associations are still accessible, even on destroyed records, but cloned models will not be frozen.



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# File 'lib/active_record/core.rb', line 654

def freeze
  @attributes = @attributes.clone.freeze
  self
end

#frozen? ⇒ Boolean

Returns true if the attributes hash has been frozen.

Returns:

  • (Boolean) 


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# File 'lib/active_record/core.rb', line 660

def frozen?
  @attributes.frozen?
end

#full_inspect ⇒ Object

Returns all attributes of the record as a nicely formatted string, ignoring .attributes_for_inspect.

Post.first.full_inspect
#=> "#<Post id: 1, title: "Hello, World!", published_at: "2023-10-23 14:28:11 +0000">"



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# File 'lib/active_record/core.rb', line 792

def full_inspect
  inspect_with_attributes(all_attributes_for_inspect)
end

#hash ⇒ Object

Delegates to id in order to allow two records of the same type and id to work with something like:

[ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ]



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# File 'lib/active_record/core.rb', line 641

def hash
  id = self.id

  if primary_key_values_present?
    self.class.hash ^ id.hash
  else
    super
  end
end

#init_attributes(_) ⇒ Object

:nodoc:



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# File 'lib/active_record/core.rb', line 563

def init_attributes(_) # :nodoc:
  attrs = @attributes.deep_dup

  if self.class.composite_primary_key?
    @primary_key.each { |key| attrs.reset(key) }
  else
    attrs.reset(@primary_key)
  end

  attrs
end

#init_with(coder, &block) ⇒ Object

Initialize an empty model object from coder. coder should be the result of previously encoding an Active Record model, using #encode_with.

class Post < ActiveRecord::Base
end

old_post = Post.new(title: "hello world")
coder = {}
old_post.encode_with(coder)

post = Post.allocate
post.init_with(coder)
post.title # => 'hello world'



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# File 'lib/active_record/core.rb', line 498

def init_with(coder, &block)
  coder = LegacyYamlAdapter.convert(coder)
  attributes = self.class.yaml_encoder.decode(coder)
  init_with_attributes(attributes, coder["new_record"], &block)
end

#init_with_attributes(attributes, new_record = false) {|_self| ... } ⇒ Object

Initialize an empty model object from attributes. attributes should be an attributes object, and unlike the ‘initialize` method, no assignment calls are made per attribute.

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/active_record/core.rb', line 508

def init_with_attributes(attributes, new_record = false) # :nodoc:
  @new_record = new_record
  @attributes = attributes

  init_internals

  yield self if block_given?

  _run_find_callbacks
  _run_initialize_callbacks

  self
end

#initialize(attributes = nil) {|_self| ... } ⇒ Object

New objects can be instantiated as either empty (pass no construction parameter) or pre-set with attributes but not yet saved (pass a hash with key names matching the associated table column names). In both instances, valid attribute keys are determined by the column names of the associated table – hence you can’t have attributes that aren’t part of the table columns.

Example

# Instantiates a single new object
User.new(first_name: 'Jamie')

Yields:

  • (_self)

Yield Parameters:



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# File 'lib/active_record/core.rb', line 471

def initialize(attributes = nil)
  @new_record = true
  @attributes = self.class._default_attributes.deep_dup

  init_internals
  initialize_internals_callback

  super

  yield self if block_given?
  _run_initialize_callbacks
end

#initialize_dup(other) ⇒ Object

:nodoc:



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# File 'lib/active_record/core.rb', line 550

def initialize_dup(other) # :nodoc:
  @attributes = init_attributes(other)

  _run_initialize_callbacks

  @new_record               = true
  @previously_new_record    = false
  @destroyed                = false
  @_start_transaction_state = nil

  super
end

#inspect ⇒ Object

Returns the attributes of the record as a nicely formatted string.

Post.first.inspect
#=> "#<Post id: 1, title: "Hello, World!", published_at: "2023-10-23 14:28:11 +0000">"

The attributes can be limited by setting .attributes_for_inspect.

Post.attributes_for_inspect = [:id, :title]
Post.first.inspect
#=> "#<Post id: 1, title: "Hello, World!">"



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# File 'lib/active_record/core.rb', line 782

def inspect
  inspect_with_attributes(attributes_for_inspect)
end

#present? ⇒ Boolean

:nodoc:

Returns:

  • (Boolean) 


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# File 'lib/active_record/core.rb', line 673

def present? # :nodoc:
  true
end

#pretty_print(pp) ⇒ Object

Takes a PP and prettily prints this record to it, allowing you to get a nice result from pp record when pp is required.



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# File 'lib/active_record/core.rb', line 798

def pretty_print(pp)
  return super if custom_inspect_method_defined?
  pp.object_address_group(self) do
    if @attributes
      attr_names = attributes_for_inspect.select { |name| _has_attribute?(name.to_s) }
      pp.seplist(attr_names, proc { pp.text "," }) do |attr_name|
        attr_name = attr_name.to_s
        pp.breakable " "
        pp.group(1) do
          pp.text attr_name
          pp.text ":"
          pp.breakable
          value = attribute_for_inspect(attr_name)
          pp.text value
        end
      end
    else
      pp.breakable " "
      pp.text "not initialized"
    end
  end
end

#readonly! ⇒ Object

Prevents records from being written to the database:

customer = Customer.new
customer.readonly!
customer.save # raises ActiveRecord::ReadOnlyRecord

customer = Customer.first
customer.readonly!
customer.update(name: 'New Name') # raises ActiveRecord::ReadOnlyRecord

Read-only records cannot be deleted from the database either:

customer = Customer.first
customer.readonly!
customer.destroy # raises ActiveRecord::ReadOnlyRecord

Please, note that the objects themselves are still mutable in memory:

customer = Customer.new
customer.readonly!
customer.name = 'New Name' # OK

but you won’t be able to persist the changes.



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# File 'lib/active_record/core.rb', line 764

def readonly!
  @readonly = true
end

#readonly? ⇒ Boolean

Returns true if the record is read only.

Returns:

  • (Boolean) 


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# File 'lib/active_record/core.rb', line 682

def readonly?
  @readonly
end

#strict_loading!(value = true, mode: :all) ⇒ Object

Sets the record to strict_loading mode. This will raise an error if the record tries to lazily load an association.

user = User.first
user.strict_loading! # => true
user.address.city
=> ActiveRecord::StrictLoadingViolationError
user.comments.to_a
=> ActiveRecord::StrictLoadingViolationError

Parameters

  • value - Boolean specifying whether to enable or disable strict loading.

  • :mode - Symbol specifying strict loading mode. Defaults to :all. Using :n_plus_one_only mode will only raise an error if an association that will lead to an n plus one query is lazily loaded.

Examples

user = User.first
user.strict_loading!(false) # => false
user.address.city # => "Tatooine"
user.comments.to_a # => [#<Comment:0x00...]

user.strict_loading!(mode: :n_plus_one_only)
user.address.city # => "Tatooine"
user.comments.to_a # => [#<Comment:0x00...]
user.comments.first.ratings.to_a
=> ActiveRecord::StrictLoadingViolationError



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# File 'lib/active_record/core.rb', line 720

def strict_loading!(value = true, mode: :all)
  unless [:all, :n_plus_one_only].include?(mode)
    raise ArgumentError, "The :mode option must be one of [:all, :n_plus_one_only] but #{mode.inspect} was provided."
  end

  @strict_loading_mode = mode
  @strict_loading = value
end

#strict_loading? ⇒ Boolean

Returns true if the record is in strict_loading mode.

Returns:

  • (Boolean) 


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# File 'lib/active_record/core.rb', line 687

def strict_loading?
  @strict_loading
end

#strict_loading_all? ⇒ Boolean

Returns true if the record uses strict_loading with :all mode enabled.

Returns:

  • (Boolean) 


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# File 'lib/active_record/core.rb', line 737

def strict_loading_all?
  @strict_loading_mode == :all
end

#strict_loading_n_plus_one_only? ⇒ Boolean

Returns true if the record uses strict_loading with :n_plus_one_only mode enabled.

Returns:

  • (Boolean) 


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# File 'lib/active_record/core.rb', line 732

def strict_loading_n_plus_one_only?
  @strict_loading_mode == :n_plus_one_only
end