Module: ActiveRecord::Core

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

Defined Under Namespace

Modules: ClassMethods

Instance Method Summary collapse

Instance Method Details

#<=>(other_object) ⇒ Object

Allows sort on objects


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# File 'lib/active_record/core.rb', line 452

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 420

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

#connection_handlerObject


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

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 405

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

#freezeObject

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 441

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 447

def frozen?
  @attributes.frozen?
end

#hashObject

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 430

def hash
  if id
    self.class.hash ^ id.hash
  else
    super
  end
end

#init_with(coder) {|_self| ... } ⇒ 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'

Yields:

  • (_self)

Yield Parameters:


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# File 'lib/active_record/core.rb', line 334

def init_with(coder)
  coder = LegacyYamlAdapter.convert(self.class, coder)
  @attributes = self.class.yaml_encoder.decode(coder)

  init_internals

  @new_record = coder["new_record"]

  self.class.define_attribute_methods

  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 307

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

  init_internals
  initialize_internals_callback

  assign_attributes(attributes) if attributes

  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 379

def initialize_dup(other) # :nodoc:
  @attributes = @attributes.deep_dup
  @attributes.reset(self.class.primary_key)

  _run_initialize_callbacks

  @new_record               = true
  @destroyed                = false
  @_start_transaction_state = {}
  @transaction_state        = nil

  super
end

#inspectObject

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


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# File 'lib/active_record/core.rb', line 476

def inspect
  # We check defined?(@attributes) not to issue warnings if the object is
  # allocated but not initialized.
  inspection = if defined?(@attributes) && @attributes
    self.class.attribute_names.collect do |name|
      if has_attribute?(name)
        "#{name}: #{attribute_for_inspect(name)}"
      end
    end.compact.join(", ")
  else
    "not initialized"
  end

  "#<#{self.class} #{inspection}>"
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 494

def pretty_print(pp)
  return super if custom_inspect_method_defined?
  pp.object_address_group(self) do
    if defined?(@attributes) && @attributes
      column_names = self.class.column_names.select { |name| has_attribute?(name) || new_record? }
      pp.seplist(column_names, proc { pp.text "," }) do |column_name|
        column_value = read_attribute(column_name)
        pp.breakable " "
        pp.group(1) do
          pp.text column_name
          pp.text ":"
          pp.breakable
          pp.pp column_value
        end
      end
    else
      pp.breakable " "
      pp.text "not initialized"
    end
  end
end

#readonly!Object

Marks this record as read only.


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# File 'lib/active_record/core.rb', line 467

def readonly!
  @readonly = true
end

#readonly?Boolean

Returns true if the record is read only. Records loaded through joins with piggy-back attributes will be marked as read only since they cannot be saved.

Returns:

  • (Boolean)

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# File 'lib/active_record/core.rb', line 462

def readonly?
  @readonly
end

#slice(*methods) ⇒ Object

Returns a hash of the given methods with their names as keys and returned values as values.


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# File 'lib/active_record/core.rb', line 517

def slice(*methods)
  Hash[methods.flatten.map! { |method| [method, public_send(method)] }].with_indifferent_access
end