module ActiveRecord::Core
Public Class Methods
Returns fully resolved ActiveRecord::DatabaseConfigurations
object
# File lib/active_record/core.rb, line 69 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: db/development.sqlite3 production: adapter: sqlite3 database: db/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: "db/development.sqlite3"}>, #<ActiveRecord::DatabaseConfigurations::HashConfig:0x00007fd1acbdea90 @env_name="production", @name="primary", @config={adapter: "sqlite3", database: "db/production.sqlite3"}> ]>
# File lib/active_record/core.rb, line 63 def self.configurations=(config) @@configurations = ActiveRecord::DatabaseConfigurations.new(config) end
# File lib/active_record/core.rb, line 276 def self.connection_class # :nodoc @connection_class ||= false end
# File lib/active_record/core.rb, line 175 def self.connection_handler Thread.current.thread_variable_get(:ar_connection_handler) || default_connection_handler end
# File lib/active_record/core.rb, line 179 def self.connection_handler=(handler) Thread.current.thread_variable_set(:ar_connection_handler, handler) end
# File lib/active_record/core.rb, line 183 def self.connection_handlers unless legacy_connection_handling raise NotImplementedError, "The new connection handling does not support accessing multiple connection handlers." end @@connection_handlers ||= {} end
# File lib/active_record/core.rb, line 191 def self.connection_handlers=(handlers) unless legacy_connection_handling raise NotImplementedError, "The new connection handling does not setting support multiple connection handlers." end @@connection_handlers = handlers 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
# File lib/active_record/core.rb, line 249 def self.current_preventing_writes if legacy_connection_handling connection_handler.prevent_writes else 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_classes) end false end 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
# File lib/active_record/core.rb, line 208 def self.current_role if ActiveRecord::Base.legacy_connection_handling connection_handlers.key(connection_handler) || default_role else 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_classes) end default_role end 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
# File lib/active_record/core.rb, line 230 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_classes) end default_shard end
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 518 def initialize(attributes = nil) @new_record = true @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
Allows sort on objects
# File lib/active_record/core.rb, line 669 def <=>(other_object) if other_object.is_a?(self.class) to_key <=> other_object.to_key else super end end
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.
# File lib/active_record/core.rb, line 637 def ==(comparison_object) super || comparison_object.instance_of?(self.class) && !id.nil? && 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
# File lib/active_record/core.rb, line 570
# File lib/active_record/core.rb, line 711 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).
# File lib/active_record/core.rb, line 587
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 622 def encode_with(coder) self.class.yaml_encoder.encode(@attributes, coder) coder["new_record"] = new_record? coder["active_record_yaml_version"] = 2 end
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 658 def freeze @attributes = @attributes.clone.freeze self end
Returns true
if the attributes hash has been frozen.
# File lib/active_record/core.rb, line 664 def frozen? @attributes.frozen? 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) ]
# File lib/active_record/core.rb, line 647 def hash if id 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'
# File lib/active_record/core.rb, line 545 def init_with(coder, &block) coder = LegacyYamlAdapter.convert(self.class, coder) attributes = self.class.yaml_encoder.decode(coder) init_with_attributes(attributes, coder["new_record"], &block) end
Returns the contents of the record as a nicely formatted string.
# File lib/active_record/core.rb, line 716 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
Takes a PP and prettily prints this record to it, allowing you to get a nice result from pp record
when pp is required.
# File lib/active_record/core.rb, line 734 def pretty_print(pp) return super if custom_inspect_method_defined? pp.object_address_group(self) do if defined?(@attributes) && @attributes attr_names = self.class.attribute_names.select { |name| _has_attribute?(name) } pp.seplist(attr_names, proc { pp.text "," }) do |attr_name| 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.
# File lib/active_record/core.rb, line 707 def readonly! @readonly = true end
Returns true
if the record is read only.
# File lib/active_record/core.rb, line 686 def readonly? @readonly end
Returns a hash of the given methods with their names as keys and returned values as values.
# File lib/active_record/core.rb, line 758 def slice(*methods) methods.flatten.index_with { |method| public_send(method) }.with_indifferent_access end
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! user.comments.to_a => ActiveRecord::StrictLoadingViolationError
# File lib/active_record/core.rb, line 702 def strict_loading! @strict_loading = true end
Returns true
if the record is in strict_loading mode.
# File lib/active_record/core.rb, line 691 def strict_loading? @strict_loading end
Returns an array of the values returned by the given methods.
# File lib/active_record/core.rb, line 763 def values_at(*methods) methods.flatten.map! { |method| public_send(method) } end
Private Instance Methods
# File lib/active_record/core.rb, line 796 def custom_inspect_method_defined? self.class.instance_method(:inspect).owner != ActiveRecord::Base.instance_method(:inspect).owner end
# File lib/active_record/core.rb, line 780 def init_internals @primary_key = self.class.primary_key @readonly = false @previously_new_record = false @destroyed = false @marked_for_destruction = false @destroyed_by_association = nil @_start_transaction_state = nil @strict_loading = self.class.strict_loading_by_default self.class.define_attribute_methods end
# File lib/active_record/core.rb, line 793 def initialize_internals_callback end
# File lib/active_record/core.rb, line 807 def inspection_filter self.class.inspection_filter end
+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 776 def to_ary nil end