Namespace
Methods
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Class Public methods
connection_handler()
# File activerecord/lib/active_record/core.rb, line 82
def self.connection_handler
  ActiveRecord::RuntimeRegistry.connection_handler || default_connection_handler
end
connection_handler=(handler)
# File activerecord/lib/active_record/core.rb, line 86
def self.connection_handler=(handler)
  ActiveRecord::RuntimeRegistry.connection_handler = handler
end
new(attributes = nil, options = {})

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 activerecord/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
Instance Public methods
<=>(other_object)

Allows sort on objects

# File activerecord/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
==(comparison_object)

Returns true if comparison_objectis the same exact object, or comparison_objectis 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 selectand 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.

Also aliased as: eql?
# File activerecord/lib/active_record/core.rb, line 290
def ==(comparison_object)
  super ||
    comparison_object.instance_of?(self.class) &&
    id.present? &&
    comparison_object.id == id
end
clone

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 233
    
connection()

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 activerecord/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
connection_handler()
# File activerecord/lib/active_record/core.rb, line 343
def connection_handler
  self.class.connection_handler
end
dup

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 242
    
encode_with(coder)

Populate coderwith attributes about this record that should be serialized. The structure of coderdefined in this method is guaranteed to match the structure of coderpassed to the init_withmethod.

Example:

class Post < ActiveRecord::Base
end
coder = {}
Post.new.encode_with(coder)
coder # => {"attributes" => {"id" => nil, ... }}
# File activerecord/lib/active_record/core.rb, line 277
def encode_with(coder)
  coder['attributes'] = attributes
end
eql?(comparison_object)
Alias for: ==
freeze()

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 307
def freeze
  @attributes = @attributes.clone.freeze
  self
end
frozen?()

Returns trueif the attributes hash has been frozen.

# File activerecord/lib/active_record/core.rb, line 313
def frozen?
  @attributes.frozen?
end
hash()

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 300
def hash
  id.hash
end
init_with(coder)

Initialize an empty model object from coder. codermust 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 activerecord/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
inspect()

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

# File activerecord/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
readonly!()

Marks this record as read only.

# File activerecord/lib/active_record/core.rb, line 331
def readonly!
  @readonly = true
end
readonly?()

Returns trueif 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 activerecord/lib/active_record/core.rb, line 326
def readonly?
  @readonly
end
slice(*methods)

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 364
def slice(*methods)
  Hash[methods.map { |method| [method, public_send(method)] }].with_indifferent_access
end