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Diffstat (limited to 'activerecord/lib/active_record/core.rb')
-rw-r--r-- | activerecord/lib/active_record/core.rb | 393 |
1 files changed, 393 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb new file mode 100644 index 0000000000..f2833fbf3c --- /dev/null +++ b/activerecord/lib/active_record/core.rb @@ -0,0 +1,393 @@ +require 'active_support/concern' +require 'active_support/core_ext/hash/indifferent_access' +require 'active_support/core_ext/object/deep_dup' +require 'thread' + +module ActiveRecord + module Core + extend ActiveSupport::Concern + + included do + ## + # :singleton-method: + # Accepts a logger conforming to the interface of Log4r or the default Ruby 1.8+ Logger class, + # which is then passed on to any new database connections made and which can be retrieved on both + # a class and instance level by calling +logger+. + config_attribute :logger, :global => true + + ## + # :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 ActiveRecord::Base.configurations to look like this: + # + # { + # 'development' => { + # 'adapter' => 'sqlite3', + # 'database' => 'db/development.sqlite3' + # }, + # 'production' => { + # 'adapter' => 'sqlite3', + # 'database' => 'db/production.sqlite3' + # } + # } + config_attribute :configurations, :global => true + self.configurations = {} + + ## + # :singleton-method: + # Determines whether to use Time.utc (using :utc) or Time.local (using :local) when pulling + # dates and times from the database. This is set to :utc by default. + config_attribute :default_timezone, :global => true + self.default_timezone = :utc + + ## + # :singleton-method: + # Specifies the format to use when dumping the database schema with Rails' + # Rakefile. If :sql, the schema is dumped as (potentially database- + # specific) SQL statements. If :ruby, the schema is dumped as an + # ActiveRecord::Schema file which can be loaded into any database that + # supports migrations. Use :ruby if you want to have different database + # adapters for, e.g., your development and test environments. + config_attribute :schema_format, :global => true + self.schema_format = :ruby + + ## + # :singleton-method: + # Specify whether or not to use timestamps for migration versions + config_attribute :timestamped_migrations, :global => true + self.timestamped_migrations = true + + ## + # :singleton-method: + # The connection handler + config_attribute :connection_handler + self.connection_handler = ConnectionAdapters::ConnectionHandler.new + + ## + # :singleton-method: + # Specifies whether or not has_many or has_one association option + # :dependent => :restrict raises an exception. If set to true, the + # ActiveRecord::DeleteRestrictionError exception will be raised + # along with a DEPRECATION WARNING. If set to false, an error would + # be added to the model instead. + config_attribute :dependent_restrict_raises, :global => true + self.dependent_restrict_raises = true + end + + module ClassMethods + def inherited(child_class) #:nodoc: + child_class.initialize_generated_modules + super + end + + def initialize_generated_modules + @attribute_methods_mutex = Mutex.new + + # force attribute methods to be higher in inheritance hierarchy than other generated methods + generated_attribute_methods + generated_feature_methods + end + + def generated_feature_methods + @generated_feature_methods ||= begin + mod = const_set(:GeneratedFeatureMethods, Module.new) + include mod + mod + end + end + + # Returns a string like 'Post(id:integer, title:string, body:text)' + def inspect + if self == Base + super + elsif abstract_class? + "#{super}(abstract)" + elsif table_exists? + attr_list = columns.map { |c| "#{c.name}: #{c.type}" } * ', ' + "#{super}(#{attr_list})" + else + "#{super}(Table doesn't exist)" + end + end + + # Overwrite the default class equality method to provide support for association proxies. + def ===(object) + object.is_a?(self) + end + + # Returns an instance of <tt>Arel::Table</tt> loaded with the current table name. + # + # class Post < ActiveRecord::Base + # scope :published_and_commented, published.and(self.arel_table[:comments_count].gt(0)) + # end + def arel_table + @arel_table ||= Arel::Table.new(table_name, arel_engine) + end + + # Returns the Arel engine. + def arel_engine + @arel_engine ||= connection_handler.retrieve_connection_pool(self) ? self : active_record_super.arel_engine + end + + private + + def relation #:nodoc: + relation = Relation.new(self, arel_table) + + if finder_needs_type_condition? + relation.where(type_condition).create_with(inheritance_column.to_sym => sti_name) + else + relation + end + end + 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. + # + # +initialize+ respects mass-assignment security and accepts either +:as+ or +:without_protection+ options + # in the +options+ parameter. + # + # ==== Examples + # # Instantiates a single new object + # User.new(:first_name => 'Jamie') + # + # # Instantiates a single new object using the :admin mass-assignment security role + # User.new({ :first_name => 'Jamie', :is_admin => true }, :as => :admin) + # + # # Instantiates a single new object bypassing mass-assignment security + # User.new({ :first_name => 'Jamie', :is_admin => true }, :without_protection => true) + def initialize(attributes = nil, options = {}) + @attributes = self.class.initialize_attributes(self.class.column_defaults.deep_dup) + @columns_hash = self.class.column_types.dup + + init_internals + + ensure_proper_type + + populate_with_current_scope_attributes + + assign_attributes(attributes, options) if attributes + + yield self if block_given? + run_callbacks :initialize if _initialize_callbacks.any? + 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' + def init_with(coder) + @attributes = self.class.initialize_attributes(coder['attributes']) + @columns_hash = self.class.column_types.merge(coder['column_types'] || {}) + + init_internals + + @new_record = false + + run_callbacks :find + run_callbacks :initialize + + self + end + + ## + # :method: 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 + + ## + # :method: 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). + + ## + def initialize_dup(other) # :nodoc: + cloned_attributes = other.clone_attributes(:read_attribute_before_type_cast) + self.class.initialize_attributes(cloned_attributes) + + cloned_attributes.delete(self.class.primary_key) + + @attributes = cloned_attributes + @attributes[self.class.primary_key] = nil + + run_callbacks(:initialize) if _initialize_callbacks.any? + + @changed_attributes = {} + self.class.column_defaults.each do |attr, orig_value| + @changed_attributes[attr] = orig_value if _field_changed?(attr, orig_value, @attributes[attr]) + end + + @aggregation_cache = {} + @association_cache = {} + @attributes_cache = {} + + @new_record = true + + ensure_proper_type + populate_with_current_scope_attributes + super + 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, ... }} + def encode_with(coder) + coder['attributes'] = attributes + 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. + def ==(comparison_object) + super || + comparison_object.instance_of?(self.class) && + id.present? && + comparison_object.id == id + end + alias :eql? :== + + # 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) ] + def hash + id.hash + end + + # Freeze the attributes hash such that associations are still accessible, even on destroyed records. + def freeze + @attributes.freeze; self + end + + # Returns +true+ if the attributes hash has been frozen. + def frozen? + @attributes.frozen? + end + + # Allows sort on objects + def <=>(other_object) + if other_object.is_a?(self.class) + self.to_key <=> other_object.to_key + else + nil + end + 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. + def readonly? + @readonly + end + + # Marks this record as read only. + def readonly! + @readonly = true + end + + # 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. + def connection + self.class.connection + end + + # Returns the contents of the record as a nicely formatted string. + def inspect + inspection = if @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 + + # Returns a hash of the given methods with their names as keys and returned values as values. + def slice(*methods) + Hash[methods.map { |method| [method, public_send(method)] }].with_indifferent_access + end + + private + + # Under Ruby 1.9, 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 http://tenderlovemaking.com/2011/06/28/til-its-ok-to-return-nil-from-to_ary/ + def to_ary # :nodoc: + nil + end + + 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 + @new_record = true + end + end +end |