module ActiveRecord::Core
Public Class Methods
# File activerecord/lib/active_record/core.rb, line 69 def self.configurations @@configurations end
Returns fully resolved ActiveRecord::DatabaseConfigurations object
# File activerecord/lib/active_record/core.rb, line 63 def self.configurations=(config) @@configurations = ActiveRecord::DatabaseConfigurations.new(config) 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 activerecord/lib/active_record/core.rb, line 160 def self.connection_handler Thread.current.thread_variable_get(:ar_connection_handler) || default_connection_handler end
# File activerecord/lib/active_record/core.rb, line 164 def self.connection_handler=(handler) Thread.current.thread_variable_set(:ar_connection_handler, handler) end
# File activerecord/lib/active_record/core.rb, line 168
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 activerecord/lib/active_record/core.rb, line 176
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 # File activerecord/lib/active_record/core.rb, line 234
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?(abstract_base_class)
end
false
end
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 activerecord/lib/active_record/core.rb, line 193
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?(abstract_base_class)
end
default_role
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 activerecord/lib/active_record/core.rb, line 215
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?(abstract_base_class)
end
default_shard
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 activerecord/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 assign_attributes(attributes) if attributes yield self if block_given? _run_initialize_callbacks 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')
Public Instance Methods
# File activerecord/lib/active_record/core.rb, line 622
def <=>(other_object)
if other_object.is_a?(self.class)
to_key <=> other_object.to_key
else
super
end
end Allows sort on objects
# File activerecord/lib/active_record/core.rb, line 590
def ==(comparison_object)
super ||
comparison_object.instance_of?(self.class) &&
!id.nil? &&
comparison_object.id == id
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 activerecord/lib/active_record/core.rb, line 523
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 activerecord/lib/active_record/core.rb, line 664 def connection_handler self.class.connection_handler end
# File activerecord/lib/active_record/core.rb, line 540
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 activerecord/lib/active_record/core.rb, line 575 def encode_with(coder) self.class.yaml_encoder.encode(@attributes, coder) coder["new_record"] = new_record? coder["active_record_yaml_version"] = 2 end
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 activerecord/lib/active_record/core.rb, line 611 def freeze @attributes = @attributes.clone.freeze self 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 activerecord/lib/active_record/core.rb, line 617 def frozen? @attributes.frozen? end
Returns true if the attributes hash has been frozen.
# File activerecord/lib/active_record/core.rb, line 600
def hash
if id
self.class.hash ^ id.hash
else
super
end
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 activerecord/lib/active_record/core.rb, line 498 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
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 activerecord/lib/active_record/core.rb, line 669
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 Returns the contents of the record as a nicely formatted string.
# File activerecord/lib/active_record/core.rb, line 687
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 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 activerecord/lib/active_record/core.rb, line 660 def readonly! @readonly = true end
Marks this record as read only.
# File activerecord/lib/active_record/core.rb, line 639 def readonly? @readonly end
Returns true if the record is read only.
# File activerecord/lib/active_record/core.rb, line 711
def slice(*methods)
methods.flatten.index_with { |method| public_send(method) }.with_indifferent_access
end Returns a hash of the given methods with their names as keys and returned values as values.
# File activerecord/lib/active_record/core.rb, line 655 def strict_loading! @strict_loading = true 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 activerecord/lib/active_record/core.rb, line 644 def strict_loading? @strict_loading end
Returns true if the record is in strict_loading mode.
# File activerecord/lib/active_record/core.rb, line 716
def values_at(*methods)
methods.flatten.map! { |method| public_send(method) }
end Returns an array of the values returned by the given methods.
© 2004–2020 David Heinemeier Hansson
Licensed under the MIT License.