module ActiveRecord::Core

Public Class Methods

configurations() click to toggle source

Returns fully resolved configurations hash

# File lib/active_record/core.rb, line 59
def self.configurations
  @@configurations
end
configurations=(config) click to toggle source

Contains the database configuration - as is typically stored in config/database.yml - as a Hash.

For example, the following database.yml…

development:
  adapter: sqlite3
  database: db/development.sqlite3

production:
  adapter: sqlite3
  database: db/production.sqlite3

…would result in ActiveRecord::Base.configurations to look like this:

{
   'development' => {
      'adapter'  => 'sqlite3',
      'database' => 'db/development.sqlite3'
   },
   'production' => {
      'adapter'  => 'sqlite3',
      'database' => 'db/production.sqlite3'
   }
}
# File lib/active_record/core.rb, line 53
def self.configurations=(config)
  @@configurations = ActiveRecord::ConnectionHandling::MergeAndResolveDefaultUrlConfig.new(config).resolve
end
connection_handler() click to toggle source
# File lib/active_record/core.rb, line 130
def self.connection_handler
  ActiveRecord::RuntimeRegistry.connection_handler || default_connection_handler
end
connection_handler=(handler) click to toggle source
# File lib/active_record/core.rb, line 134
def self.connection_handler=(handler)
  ActiveRecord::RuntimeRegistry.connection_handler = handler
end
new(attributes = nil) { |self| ... } click to toggle source

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')
# File lib/active_record/core.rb, line 308
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

Public Instance Methods

<=>(other_object) click to toggle source

Allows sort on objects

Calls superclass method
# File lib/active_record/core.rb, line 453
def <=>(other_object)
  if other_object.is_a?(self.class)
    to_key <=> other_object.to_key
  else
    super
  end
end
==(comparison_object) click to toggle source

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.

Calls superclass method
# File lib/active_record/core.rb, line 421
def ==(comparison_object)
  super ||
    comparison_object.instance_of?(self.class) &&
    !id.nil? &&
    comparison_object.id == id
end
Also aliased as: eql?
clone() click to toggle source

Identical to Ruby's clone method. This is a “shallow” copy. Be warned that your attributes are not copied. That means that modifying attributes of the clone will modify the original, since they will both point to the same attributes hash. If you need a copy of your attributes hash, please use the dup method.

user = User.first
new_user = user.clone
user.name               # => "Bob"
new_user.name = "Joe"
user.name               # => "Joe"

user.object_id == new_user.object_id            # => false
user.name.object_id == new_user.name.object_id  # => true

user.name.object_id == user.dup.name.object_id  # => false
# File lib/active_record/core.rb, line 370
    
connection_handler() click to toggle source
# File lib/active_record/core.rb, line 472
def connection_handler
  self.class.connection_handler
end
dup() click to toggle source

Duped objects have no id assigned and are treated as new records. Note that this is a “shallow” copy as it copies the object's attributes only, not its associations. The extent of a “deep” copy is application specific and is therefore left to the application to implement according to its need. The dup method does not preserve the timestamps (created|updated)_(at|on).

# File lib/active_record/core.rb, line 379
    
encode_with(coder) click to toggle source

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, ... }}
# File lib/active_record/core.rb, line 406
def encode_with(coder)
  self.class.yaml_encoder.encode(@attributes, coder)
  coder["new_record"] = new_record?
  coder["active_record_yaml_version"] = 2
end
eql?(comparison_object)
Alias for: ==
freeze() click to toggle source

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

# File lib/active_record/core.rb, line 442
def freeze
  @attributes = @attributes.clone.freeze
  self
end
frozen?() click to toggle source

Returns true if the attributes hash has been frozen.

# File lib/active_record/core.rb, line 448
def frozen?
  @attributes.frozen?
end
hash() click to toggle source

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) ]
Calls superclass method
# File lib/active_record/core.rb, line 431
def hash
  if id
    self.class.hash ^ id.hash
  else
    super
  end
end
init_with(coder) { |self| ... } click to toggle source

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'
# File lib/active_record/core.rb, line 335
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
inspect() click to toggle source

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

# File lib/active_record/core.rb, line 477
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) click to toggle source

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

Calls superclass method
# File lib/active_record/core.rb, line 495
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!() click to toggle source

Marks this record as read only.

# File lib/active_record/core.rb, line 468
def readonly!
  @readonly = true
end
readonly?() click to toggle source

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.

# File lib/active_record/core.rb, line 463
def readonly?
  @readonly
end
slice(*methods) click to toggle source

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

# File lib/active_record/core.rb, line 518
def slice(*methods)
  Hash[methods.flatten.map! { |method| [method, public_send(method)] }].with_indifferent_access
end

Private Instance Methods

custom_inspect_method_defined?() click to toggle source
# File lib/active_record/core.rb, line 555
def custom_inspect_method_defined?
  self.class.instance_method(:inspect).owner != ActiveRecord::Base.instance_method(:inspect).owner
end
init_internals() click to toggle source
# File lib/active_record/core.rb, line 536
def init_internals
  @readonly                 = false
  @destroyed                = false
  @marked_for_destruction   = false
  @destroyed_by_association = nil
  @new_record               = true
  @_start_transaction_state = {}
  @transaction_state        = nil
end
initialize_internals_callback() click to toggle source
# File lib/active_record/core.rb, line 546
def initialize_internals_callback
end
thaw() click to toggle source
# File lib/active_record/core.rb, line 549
def thaw
  if frozen?
    @attributes = @attributes.dup
  end
end
to_ary() click to toggle source

+Array#flatten+ will call #to_ary (recursively) on each of the elements of the array, and then rescues from the possible NoMethodError. If those elements are ActiveRecord::Base's, then this triggers the various method_missing's that we have, which significantly impacts upon performance.

So we can avoid the method_missing hit by explicitly defining #to_ary as nil here.

See also tenderlovemaking.com/2011/06/28/til-its-ok-to-return-nil-from-to_ary.html

# File lib/active_record/core.rb, line 532
def to_ary
  nil
end