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module ActiveRecord::Core

Active Record Core

Attributes

[R] strict_loading_mode

Public class methods

Returns a fully resolved ActiveRecord::DatabaseConfigurations object.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 77
def self.configurations
  @@configurations
end

Contains the database configuration - as is typically stored in config/database.yml - as an ActiveRecord::DatabaseConfigurations object.

For example, the following database.yml…

development:
  adapter: sqlite3
  database: storage/development.sqlite3

production:
  adapter: sqlite3
  database: storage/production.sqlite3

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

#<ActiveRecord::DatabaseConfigurations:0x00007fd1acbdf800 @configurations=[
  #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbded10 @env_name="development",
    @name="primary", @config={adapter: "sqlite3", database: "storage/development.sqlite3"}>,
  #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbdea90 @env_name="production",
    @name="primary", @config={adapter: "sqlite3", database: "storage/production.sqlite3"}>
]>
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 71
def self.configurations=(config)
  @@configurations = ActiveRecord::DatabaseConfigurations.new(config)
end
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 120
def self.connection_handler
  ActiveSupport::IsolatedExecutionState[:active_record_connection_handler] || default_connection_handler
end
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 124
def self.connection_handler=(handler)
  ActiveSupport::IsolatedExecutionState[:active_record_connection_handler] = handler
end

Returns the symbol representing the current setting for preventing writes.

ActiveRecord::Base.connected_to(role: :reading) do
  ActiveRecord::Base.current_preventing_writes #=> true
end

ActiveRecord::Base.connected_to(role: :writing) do
  ActiveRecord::Base.current_preventing_writes #=> false
end
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 183
def self.current_preventing_writes
  connected_to_stack.reverse_each do |hash|
    return hash[:prevent_writes] if !hash[:prevent_writes].nil? && hash[:klasses].include?(Base)
    return hash[:prevent_writes] if !hash[:prevent_writes].nil? && hash[:klasses].include?(connection_class_for_self)
  end

  false
end

Returns the symbol representing the current connected role.

ActiveRecord::Base.connected_to(role: :writing) do
  ActiveRecord::Base.current_role #=> :writing
end

ActiveRecord::Base.connected_to(role: :reading) do
  ActiveRecord::Base.current_role #=> :reading
end
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 146
def self.current_role
  connected_to_stack.reverse_each do |hash|
    return hash[:role] if hash[:role] && hash[:klasses].include?(Base)
    return hash[:role] if hash[:role] && hash[:klasses].include?(connection_class_for_self)
  end

  default_role
end

Returns the symbol representing the current connected shard.

ActiveRecord::Base.connected_to(role: :reading) do
  ActiveRecord::Base.current_shard #=> :default
end

ActiveRecord::Base.connected_to(role: :writing, shard: :one) do
  ActiveRecord::Base.current_shard #=> :one
end
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 164
def self.current_shard
  connected_to_stack.reverse_each do |hash|
    return hash[:shard] if hash[:shard] && hash[:klasses].include?(Base)
    return hash[:shard] if hash[:shard] && hash[:klasses].include?(connection_class_for_self)
  end

  default_shard
end

Specifies the maximum number of records that will be destroyed in a single background job by the dependent: :destroy_async association option. When nil (default), all dependent records will be destroyed in a single background job. If specified, the records to be destroyed will be split into multiple background jobs.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 47
class_attribute :destroy_association_async_batch_size, instance_writer: false, instance_predicate: false, default: nil

The job class used to destroy associations in the background.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 27
def self.destroy_association_async_job
  if _destroy_association_async_job.is_a?(String)
    self._destroy_association_async_job = _destroy_association_async_job.constantize
  end
  _destroy_association_async_job
rescue NameError => error
  raise NameError, "Unable to load destroy_association_async_job: #{error.message}"
end

Force enumeration of all columns in SELECT statements. e.g. SELECT first_name, last_name FROM ... instead of SELECT * FROM ... This avoids PreparedStatementCacheExpired errors when a column is added to the database while the app is running.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 87
class_attribute :enumerate_columns_in_select_statements, instance_accessor: false, default: false

Accepts a logger conforming to the interface of Log4r or the default Ruby Logger class, which is then passed on to any new database connections made. You can retrieve this logger by calling logger on either an Active Record model class or an Active Record model instance.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 22
class_attribute :logger, instance_writer: false

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')
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 449
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

Public instance methods

Allows sort on objects

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 636
def <=>(other_object)
  if other_object.is_a?(self.class)
    to_key <=> other_object.to_key
  else
    super
  end
end

Also aliased 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.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 602
def ==(comparison_object)
  super ||
    comparison_object.instance_of?(self.class) &&
    primary_key_values_present? &&
    comparison_object.id == id
end

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

GitHub

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 721
def connection_handler
  self.class.connection_handler
end

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) and locking column.

GitHub

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, ... }}
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 558
def encode_with(coder)
  self.class.yaml_encoder.encode(@attributes, coder)
  coder["new_record"] = new_record?
  coder["active_record_yaml_version"] = 2
end

Alias for: ==.

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

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 625
def freeze
  @attributes = @attributes.clone.freeze
  self
end

Returns true if the attributes hash has been frozen.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 631
def frozen?
  @attributes.frozen?
end

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

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 731
def full_inspect
  inspect_with_attributes(attribute_names)
end

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) ]
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 612
def hash
  id = self.id

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

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'
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 476
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

Returns the attributes specified by .attributes_for_inspect as a nicely formatted string.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 726
def inspect
  inspect_with_attributes(attributes_for_inspect)
end

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

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 737
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 = _read_attribute(attr_name)
          value = inspection_filter.filter_param(attr_name, value) unless value.nil?
          pp.pp value
        end
      end
    else
      pp.breakable " "
      pp.text "not initialized"
    end
  end
end

Marks this record as read only.

customer = Customer.first
customer.readonly!
customer.save # Raises an ActiveRecord::ReadOnlyRecord
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 717
def readonly!
  @readonly = true
end

Returns true if the record is read only.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 653
def readonly?
  @readonly
end

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

topic = Topic.new(title: "Budget", author_name: "Jason")
topic.slice(:title, :author_name)
=> { "title" => "Budget", "author_name" => "Jason" }

GitHub

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
Source code GitHub
# File activerecord/lib/active_record/core.rb, line 691
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

Returns true if the record is in strict_loading mode.

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 658
def strict_loading?
  @strict_loading
end

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

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 708
def strict_loading_all?
  @strict_loading_mode == :all
end

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

Source code GitHub
# File activerecord/lib/active_record/core.rb, line 703
def strict_loading_n_plus_one_only?
  @strict_loading_mode == :n_plus_one_only
end

Returns an array of the values returned by the given methods.

topic = Topic.new(title: "Budget", author_name: "Jason")
topic.values_at(:title, :author_name)
=> ["Budget", "Jason"]

GitHub

Namespace

Definition files