# File lib/active_record/core.rb, line 82 def self.connection_handler ActiveRecord::RuntimeRegistry.connection_handler || default_connection_handler end
# File lib/active_record/core.rb, line 86 def self.connection_handler=(handler) ActiveRecord::RuntimeRegistry.connection_handler = handler 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.
# Instantiates a single new object User.new(first_name: 'Jamie')
# File lib/active_record/core.rb, line 170 def initialize(attributes = nil, options = {}) defaults = self.class.column_defaults.dup defaults.each { |k, v| defaults[k] = v.dup if v.duplicable? } @attributes = self.class.initialize_attributes(defaults) @column_types_override = nil @column_types = self.class.column_types init_internals init_changed_attributes ensure_proper_type populate_with_current_scope_attributes # +options+ argument is only needed to make protected_attributes gem easier to hook. # Remove it when we drop support to this gem. init_attributes(attributes, options) if attributes yield self if block_given? run_callbacks :initialize unless _initialize_callbacks.empty? end
Allows sort on objects
# File lib/active_record/core.rb, line 318 def <=>(other_object) if other_object.is_a?(self.class) self.to_key <=> other_object.to_key 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 290 def ==(comparison_object) super || comparison_object.instance_of?(self.class) && id.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
# File lib/active_record/core.rb, line 233
Returns the connection currently associated with the class. This can also be used to “borrow” the connection to do database work that isn't easily done without going straight to SQL.
# File lib/active_record/core.rb, line 338 def connection ActiveSupport::Deprecation.warn("#connection is deprecated in favour of accessing it via the class") self.class.connection end
# File lib/active_record/core.rb, line 343 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 242
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 277 def encode_with(coder) coder['attributes'] = attributes 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 307 def freeze @attributes = @attributes.clone.freeze self end
Returns true
if the attributes hash has been frozen.
# File lib/active_record/core.rb, line 313 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 300 def hash id.hash end
Initialize an empty model object from coder
.
coder
must contain the attributes necessary for initializing
an empty model object. For example:
class Post < ActiveRecord::Base end post = Post.allocate post.init_with('attributes' => { 'title' => 'hello world' }) post.title # => 'hello world'
# File lib/active_record/core.rb, line 201 def init_with(coder) @attributes = self.class.initialize_attributes(coder['attributes']) @column_types_override = coder['column_types'] @column_types = self.class.column_types init_internals @new_record = false run_callbacks :find run_callbacks :initialize self end
Returns the contents of the record as a nicely formatted string.
# File lib/active_record/core.rb, line 348 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.column_names.collect { |name| if has_attribute?(name) "#{name}: #{attribute_for_inspect(name)}" end }.compact.join(", ") else "not initialized" end "#<#{self.class} #{inspection}>" end
Marks this record as read only.
# File lib/active_record/core.rb, line 331 def readonly! @readonly = true end
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 326 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 364 def slice(*methods) Hash[methods.map { |method| [method, public_send(method)] }].with_indifferent_access end
This method is needed to make protected_attributes gem easier to hook. Remove it when we drop support to this gem.
# File lib/active_record/core.rb, line 459 def init_attributes(attributes, options) assign_attributes(attributes) end
# File lib/active_record/core.rb, line 448 def init_changed_attributes # Intentionally avoid using #column_defaults since overridden defaults (as is done in # optimistic locking) won't get written unless they get marked as changed self.class.columns.each do |c| attr, orig_value = c.name, c.default @changed_attributes[attr] = orig_value if _field_changed?(attr, orig_value, @attributes[attr]) end end
# File lib/active_record/core.rb, line 428 def init_internals pk = self.class.primary_key @attributes[pk] = nil unless @attributes.key?(pk) @aggregation_cache = {} @association_cache = {} @attributes_cache = {} @previously_changed = {} @changed_attributes = {} @readonly = false @destroyed = false @marked_for_destruction = false @destroyed_by_association = nil @new_record = true @txn = nil @_start_transaction_state = {} @transaction_state = nil @reflects_state = [false] end
Updates the attributes on this particular ActiveRecord object so that if it is associated with a transaction, then the state of the AR object will be updated to reflect the current state of the transaction
The @transaction_state variable stores the states of the associated transaction. This relies on the fact that a transaction can only be in one rollback or commit (otherwise a list of states would be required) Each AR object inside of a transaction carries that transaction's TransactionState.
This method checks to see if the ActiveRecord object's state reflects the TransactionState, and rolls back or commits the ActiveRecord object as appropriate.
Since ActiveRecord objects can be inside multiple transactions, this method recursively goes through the parent of the TransactionState and checks if the ActiveRecord object reflects the state of the object.
# File lib/active_record/core.rb, line 395 def sync_with_transaction_state update_attributes_from_transaction_state(@transaction_state, 0) end
# File lib/active_record/core.rb, line 399 def update_attributes_from_transaction_state(transaction_state, depth) if transaction_state && !has_transactional_callbacks? unless @reflects_state[depth] if transaction_state.committed? committed! elsif transaction_state.rolledback? rolledback! end @reflects_state[depth] = true end if transaction_state.parent && !@reflects_state[depth+1] update_attributes_from_transaction_state(transaction_state.parent, depth+1) end end end