module ActiveRecord::Core
Public Class Methods
Returns fully resolved configurations hash
# File activerecord/lib/active_record/core.rb, line 51 def self.configurations @@configurations end
:singleton-method: Contains the database configuration - as is typically stored in config/database.yml - as a Hash.
For example, the following database.yml…
development: adapter: sqlite3 database: db/development.sqlite3 production: adapter: sqlite3 database: db/production.sqlite3
…would result in ::configurations to look like this:
{
'development' => {
'adapter' => 'sqlite3',
'database' => 'db/development.sqlite3'
},
'production' => {
'adapter' => 'sqlite3',
'database' => 'db/production.sqlite3'
}
}
# File activerecord/lib/active_record/core.rb, line 45 def self.configurations=(config) @@configurations = ActiveRecord::ConnectionHandling::MergeAndResolveDefaultUrlConfig.new(config).resolve end
# File activerecord/lib/active_record/core.rb, line 97 def self.connection_handler ActiveRecord::RuntimeRegistry.connection_handler || default_connection_handler end
# File activerecord/lib/active_record/core.rb, line 101 def self.connection_handler=(handler) ActiveRecord::RuntimeRegistry.connection_handler = handler end
# File activerecord/lib/active_record/core.rb, line 90
def self.disable_implicit_join_references=(value)
ActiveSupport::Deprecation.warn("Implicit join references were removed with Rails 4.1." "Make sure to remove this configuration because it does nothing.")
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 activerecord/lib/active_record/core.rb, line 182
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
initialize_internals_callback
# +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 Public Instance Methods
Allows sort on objects
# File activerecord/lib/active_record/core.rb, line 327
def <=>(other_object)
if other_object.is_a?(self.class)
self.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 activerecord/lib/active_record/core.rb, line 299
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 activerecord/lib/active_record/core.rb, line 245
# File activerecord/lib/active_record/core.rb, line 346 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 activerecord/lib/active_record/core.rb, line 254
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 286 def encode_with(coder) coder['attributes'] = attributes_for_coder 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 316 def freeze @attributes = @attributes.clone.freeze self end
Returns true if the attributes hash has been frozen.
# File activerecord/lib/active_record/core.rb, line 322 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 activerecord/lib/active_record/core.rb, line 309 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 activerecord/lib/active_record/core.rb, line 211 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 self.class.define_attribute_methods run_callbacks :find run_callbacks :initialize self end
Returns the contents of the record as a nicely formatted string.
# File activerecord/lib/active_record/core.rb, line 351
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 activerecord/lib/active_record/core.rb, line 342 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 activerecord/lib/active_record/core.rb, line 337 def readonly? @readonly 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 367
def slice(*methods)
Hash[methods.map! { |method| [method, public_send(method)] }].with_indifferent_access
end
© 2004–2016 David Heinemeier Hansson
Licensed under the MIT License.