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rails--rails/activerecord/lib/active_record/base.rb

1960 lines
81 KiB
Ruby

begin
require 'psych'
rescue LoadError
end
require 'yaml'
require 'set'
require 'active_support/benchmarkable'
require 'active_support/dependencies'
require 'active_support/descendants_tracker'
require 'active_support/time'
require 'active_support/core_ext/class/attribute'
require 'active_support/core_ext/class/attribute_accessors'
require 'active_support/core_ext/class/delegating_attributes'
require 'active_support/core_ext/class/attribute'
require 'active_support/core_ext/array/extract_options'
require 'active_support/core_ext/hash/deep_merge'
require 'active_support/core_ext/hash/indifferent_access'
require 'active_support/core_ext/hash/slice'
require 'active_support/core_ext/string/behavior'
require 'active_support/core_ext/kernel/singleton_class'
require 'active_support/core_ext/module/delegation'
require 'active_support/core_ext/module/introspection'
require 'active_support/core_ext/object/duplicable'
require 'active_support/core_ext/object/blank'
require 'arel'
require 'active_record/errors'
require 'active_record/log_subscriber'
module ActiveRecord #:nodoc:
# = Active Record
#
# Active Record objects don't specify their attributes directly, but rather infer them from
# the table definition with which they're linked. Adding, removing, and changing attributes
# and their type is done directly in the database. Any change is instantly reflected in the
# Active Record objects. The mapping that binds a given Active Record class to a certain
# database table will happen automatically in most common cases, but can be overwritten for the uncommon ones.
#
# See the mapping rules in table_name and the full example in link:files/activerecord/README_rdoc.html for more insight.
#
# == Creation
#
# Active Records accept constructor parameters either in a hash or as a block. The hash
# method is especially useful when you're receiving the data from somewhere else, like an
# HTTP request. It works like this:
#
# user = User.new(:name => "David", :occupation => "Code Artist")
# user.name # => "David"
#
# You can also use block initialization:
#
# user = User.new do |u|
# u.name = "David"
# u.occupation = "Code Artist"
# end
#
# And of course you can just create a bare object and specify the attributes after the fact:
#
# user = User.new
# user.name = "David"
# user.occupation = "Code Artist"
#
# == Conditions
#
# Conditions can either be specified as a string, array, or hash representing the WHERE-part of an SQL statement.
# The array form is to be used when the condition input is tainted and requires sanitization. The string form can
# be used for statements that don't involve tainted data. The hash form works much like the array form, except
# only equality and range is possible. Examples:
#
# class User < ActiveRecord::Base
# def self.authenticate_unsafely(user_name, password)
# where("user_name = '#{user_name}' AND password = '#{password}'").first
# end
#
# def self.authenticate_safely(user_name, password)
# where("user_name = ? AND password = ?", user_name, password).first
# end
#
# def self.authenticate_safely_simply(user_name, password)
# where(:user_name => user_name, :password => password).first
# end
# end
#
# The <tt>authenticate_unsafely</tt> method inserts the parameters directly into the query
# and is thus susceptible to SQL-injection attacks if the <tt>user_name</tt> and +password+
# parameters come directly from an HTTP request. The <tt>authenticate_safely</tt> and
# <tt>authenticate_safely_simply</tt> both will sanitize the <tt>user_name</tt> and +password+
# before inserting them in the query, which will ensure that an attacker can't escape the
# query and fake the login (or worse).
#
# When using multiple parameters in the conditions, it can easily become hard to read exactly
# what the fourth or fifth question mark is supposed to represent. In those cases, you can
# resort to named bind variables instead. That's done by replacing the question marks with
# symbols and supplying a hash with values for the matching symbol keys:
#
# Company.where(
# "id = :id AND name = :name AND division = :division AND created_at > :accounting_date",
# { :id => 3, :name => "37signals", :division => "First", :accounting_date => '2005-01-01' }
# ).first
#
# Similarly, a simple hash without a statement will generate conditions based on equality with the SQL AND
# operator. For instance:
#
# Student.where(:first_name => "Harvey", :status => 1)
# Student.where(params[:student])
#
# A range may be used in the hash to use the SQL BETWEEN operator:
#
# Student.where(:grade => 9..12)
#
# An array may be used in the hash to use the SQL IN operator:
#
# Student.where(:grade => [9,11,12])
#
# When joining tables, nested hashes or keys written in the form 'table_name.column_name'
# can be used to qualify the table name of a particular condition. For instance:
#
# Student.joins(:schools).where(:schools => { :type => 'public' })
# Student.joins(:schools).where('schools.type' => 'public' )
#
# == Overwriting default accessors
#
# All column values are automatically available through basic accessors on the Active Record
# object, but sometimes you want to specialize this behavior. This can be done by overwriting
# the default accessors (using the same name as the attribute) and calling
# <tt>read_attribute(attr_name)</tt> and <tt>write_attribute(attr_name, value)</tt> to actually
# change things.
#
# class Song < ActiveRecord::Base
# # Uses an integer of seconds to hold the length of the song
#
# def length=(minutes)
# write_attribute(:length, minutes.to_i * 60)
# end
#
# def length
# read_attribute(:length) / 60
# end
# end
#
# You can alternatively use <tt>self[:attribute]=(value)</tt> and <tt>self[:attribute]</tt>
# instead of <tt>write_attribute(:attribute, value)</tt> and <tt>read_attribute(:attribute)</tt>.
#
# == Attribute query methods
#
# In addition to the basic accessors, query methods are also automatically available on the Active Record object.
# Query methods allow you to test whether an attribute value is present.
#
# For example, an Active Record User with the <tt>name</tt> attribute has a <tt>name?</tt> method that you can call
# to determine whether the user has a name:
#
# user = User.new(:name => "David")
# user.name? # => true
#
# anonymous = User.new(:name => "")
# anonymous.name? # => false
#
# == Accessing attributes before they have been typecasted
#
# Sometimes you want to be able to read the raw attribute data without having the column-determined
# typecast run its course first. That can be done by using the <tt><attribute>_before_type_cast</tt>
# accessors that all attributes have. For example, if your Account model has a <tt>balance</tt> attribute,
# you can call <tt>account.balance_before_type_cast</tt> or <tt>account.id_before_type_cast</tt>.
#
# This is especially useful in validation situations where the user might supply a string for an
# integer field and you want to display the original string back in an error message. Accessing the
# attribute normally would typecast the string to 0, which isn't what you want.
#
# == Dynamic attribute-based finders
#
# Dynamic attribute-based finders are a cleaner way of getting (and/or creating) objects
# by simple queries without turning to SQL. They work by appending the name of an attribute
# to <tt>find_by_</tt>, <tt>find_last_by_</tt>, or <tt>find_all_by_</tt> and thus produces finders
# like <tt>Person.find_by_user_name</tt>, <tt>Person.find_all_by_last_name</tt>, and
# <tt>Payment.find_by_transaction_id</tt>. Instead of writing
# <tt>Person.where(:user_name => user_name).first</tt>, you just do <tt>Person.find_by_user_name(user_name)</tt>.
# And instead of writing <tt>Person.where(:last_name => last_name).all</tt>, you just do
# <tt>Person.find_all_by_last_name(last_name)</tt>.
#
# It's also possible to use multiple attributes in the same find by separating them with "_and_".
#
# Person.where(:user_name => user_name, :password => password).first
# Person.find_by_user_name_and_password #with dynamic finder
#
# Person.where(:user_name => user_name, :password => password, :gender => 'male').first
# Payment.find_by_user_name_and_password_and_gender
#
# It's even possible to call these dynamic finder methods on relations and named scopes.
#
# Payment.order("created_on").find_all_by_amount(50)
# Payment.pending.find_last_by_amount(100)
#
# The same dynamic finder style can be used to create the object if it doesn't already exist.
# This dynamic finder is called with <tt>find_or_create_by_</tt> and will return the object if
# it already exists and otherwise creates it, then returns it. Protected attributes won't be set
# unless they are given in a block.
#
# # No 'Summer' tag exists
# Tag.find_or_create_by_name("Summer") # equal to Tag.create(:name => "Summer")
#
# # Now the 'Summer' tag does exist
# Tag.find_or_create_by_name("Summer") # equal to Tag.find_by_name("Summer")
#
# # Now 'Bob' exist and is an 'admin'
# User.find_or_create_by_name('Bob', :age => 40) { |u| u.admin = true }
#
# Use the <tt>find_or_initialize_by_</tt> finder if you want to return a new record without
# saving it first. Protected attributes won't be set unless they are given in a block.
#
# # No 'Winter' tag exists
# winter = Tag.find_or_initialize_by_name("Winter")
# winter.persisted? # false
#
# To find by a subset of the attributes to be used for instantiating a new object, pass a hash instead of
# a list of parameters.
#
# Tag.find_or_create_by_name(:name => "rails", :creator => current_user)
#
# That will either find an existing tag named "rails", or create a new one while setting the
# user that created it.
#
# Just like <tt>find_by_*</tt>, you can also use <tt>scoped_by_*</tt> to retrieve data. The good thing about
# using this feature is that the very first time result is returned using <tt>method_missing</tt> technique
# but after that the method is declared on the class. Henceforth <tt>method_missing</tt> will not be hit.
#
# User.scoped_by_user_name('David')
#
# == Saving arrays, hashes, and other non-mappable objects in text columns
#
# Active Record can serialize any object in text columns using YAML. To do so, you must
# specify this with a call to the class method +serialize+.
# This makes it possible to store arrays, hashes, and other non-mappable objects without doing
# any additional work.
#
# class User < ActiveRecord::Base
# serialize :preferences
# end
#
# user = User.create(:preferences => { "background" => "black", "display" => large })
# User.find(user.id).preferences # => { "background" => "black", "display" => large }
#
# You can also specify a class option as the second parameter that'll raise an exception
# if a serialized object is retrieved as a descendant of a class not in the hierarchy.
#
# class User < ActiveRecord::Base
# serialize :preferences, Hash
# end
#
# user = User.create(:preferences => %w( one two three ))
# User.find(user.id).preferences # raises SerializationTypeMismatch
#
# When you specify a class option, the default value for that attribute will be a new
# instance of that class.
#
# class User < ActiveRecord::Base
# serialize :preferences, OpenStruct
# end
#
# user = User.new
# user.preferences.theme_color = "red"
#
#
# == Single table inheritance
#
# Active Record allows inheritance by storing the name of the class in a column that by
# default is named "type" (can be changed by overwriting <tt>Base.inheritance_column</tt>).
# This means that an inheritance looking like this:
#
# class Company < ActiveRecord::Base; end
# class Firm < Company; end
# class Client < Company; end
# class PriorityClient < Client; end
#
# When you do <tt>Firm.create(:name => "37signals")</tt>, this record will be saved in
# the companies table with type = "Firm". You can then fetch this row again using
# <tt>Company.where(:name => '37signals').first</tt> and it will return a Firm object.
#
# If you don't have a type column defined in your table, single-table inheritance won't
# be triggered. In that case, it'll work just like normal subclasses with no special magic
# for differentiating between them or reloading the right type with find.
#
# Note, all the attributes for all the cases are kept in the same table. Read more:
# http://www.martinfowler.com/eaaCatalog/singleTableInheritance.html
#
# == Connection to multiple databases in different models
#
# Connections are usually created through ActiveRecord::Base.establish_connection and retrieved
# by ActiveRecord::Base.connection. All classes inheriting from ActiveRecord::Base will use this
# connection. But you can also set a class-specific connection. For example, if Course is an
# ActiveRecord::Base, but resides in a different database, you can just say <tt>Course.establish_connection</tt>
# and Course and all of its subclasses will use this connection instead.
#
# This feature is implemented by keeping a connection pool in ActiveRecord::Base that is
# a Hash indexed by the class. If a connection is requested, the retrieve_connection method
# will go up the class-hierarchy until a connection is found in the connection pool.
#
# == Exceptions
#
# * ActiveRecordError - Generic error class and superclass of all other errors raised by Active Record.
# * AdapterNotSpecified - The configuration hash used in <tt>establish_connection</tt> didn't include an
# <tt>:adapter</tt> key.
# * AdapterNotFound - The <tt>:adapter</tt> key used in <tt>establish_connection</tt> specified a
# non-existent adapter
# (or a bad spelling of an existing one).
# * AssociationTypeMismatch - The object assigned to the association wasn't of the type
# specified in the association definition.
# * SerializationTypeMismatch - The serialized object wasn't of the class specified as the second parameter.
# * ConnectionNotEstablished+ - No connection has been established. Use <tt>establish_connection</tt>
# before querying.
# * RecordNotFound - No record responded to the +find+ method. Either the row with the given ID doesn't exist
# or the row didn't meet the additional restrictions. Some +find+ calls do not raise this exception to signal
# nothing was found, please check its documentation for further details.
# * StatementInvalid - The database server rejected the SQL statement. The precise error is added in the message.
# * MultiparameterAssignmentErrors - Collection of errors that occurred during a mass assignment using the
# <tt>attributes=</tt> method. The +errors+ property of this exception contains an array of
# AttributeAssignmentError
# objects that should be inspected to determine which attributes triggered the errors.
# * AttributeAssignmentError - An error occurred while doing a mass assignment through the
# <tt>attributes=</tt> method.
# You can inspect the +attribute+ property of the exception object to determine which attribute
# triggered the error.
#
# *Note*: The attributes listed are class-level attributes (accessible from both the class and instance level).
# So it's possible to assign a logger to the class through <tt>Base.logger=</tt> which will then be used by all
# instances in the current object space.
class Base
##
# :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+.
cattr_accessor :logger, :instance_writer => false
##
# :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'
# }
# }
cattr_accessor :configurations, :instance_writer => false
@@configurations = {}
##
# :singleton-method:
# Accessor for the prefix type that will be prepended to every primary key column name.
# The options are :table_name and :table_name_with_underscore. If the first is specified,
# the Product class will look for "productid" instead of "id" as the primary column. If the
# latter is specified, the Product class will look for "product_id" instead of "id". Remember
# that this is a global setting for all Active Records.
cattr_accessor :primary_key_prefix_type, :instance_writer => false
@@primary_key_prefix_type = nil
##
# :singleton-method:
# Accessor for the name of the prefix string to prepend to every table name. So if set
# to "basecamp_", all table names will be named like "basecamp_projects", "basecamp_people",
# etc. This is a convenient way of creating a namespace for tables in a shared database.
# By default, the prefix is the empty string.
#
# If you are organising your models within modules you can add a prefix to the models within
# a namespace by defining a singleton method in the parent module called table_name_prefix which
# returns your chosen prefix.
class_attribute :table_name_prefix, :instance_writer => false
self.table_name_prefix = ""
##
# :singleton-method:
# Works like +table_name_prefix+, but appends instead of prepends (set to "_basecamp" gives "projects_basecamp",
# "people_basecamp"). By default, the suffix is the empty string.
class_attribute :table_name_suffix, :instance_writer => false
self.table_name_suffix = ""
##
# :singleton-method:
# Indicates whether table names should be the pluralized versions of the corresponding class names.
# If true, the default table name for a Product class will be +products+. If false, it would just be +product+.
# See table_name for the full rules on table/class naming. This is true, by default.
cattr_accessor :pluralize_table_names, :instance_writer => false
@@pluralize_table_names = true
##
# :singleton-method:
# Determines whether to use Time.local (using :local) or Time.utc (using :utc) when pulling
# dates and times from the database. This is set to :local by default.
cattr_accessor :default_timezone, :instance_writer => false
@@default_timezone = :local
##
# :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.
cattr_accessor :schema_format , :instance_writer => false
@@schema_format = :ruby
##
# :singleton-method:
# Specify whether or not to use timestamps for migration versions
cattr_accessor :timestamped_migrations , :instance_writer => false
@@timestamped_migrations = true
# Determine whether to store the full constant name including namespace when using STI
class_attribute :store_full_sti_class
self.store_full_sti_class = true
# Stores the default scope for the class
class_attribute :default_scoping, :instance_writer => false
self.default_scoping = []
# Returns a hash of all the attributes that have been specified for serialization as
# keys and their class restriction as values.
class_attribute :serialized_attributes
self.serialized_attributes = {}
class_attribute :_attr_readonly, :instance_writer => false
self._attr_readonly = []
class << self # Class methods
delegate :find, :first, :last, :all, :destroy, :destroy_all, :exists?, :delete, :delete_all, :update, :update_all, :to => :scoped
delegate :find_each, :find_in_batches, :to => :scoped
delegate :select, :group, :order, :except, :limit, :offset, :joins, :where, :preload, :eager_load, :includes, :from, :lock, :readonly, :having, :create_with, :to => :scoped
delegate :count, :average, :minimum, :maximum, :sum, :calculate, :to => :scoped
# Executes a custom SQL query against your database and returns all the results. The results will
# be returned as an array with columns requested encapsulated as attributes of the model you call
# this method from. If you call <tt>Product.find_by_sql</tt> then the results will be returned in
# a Product object with the attributes you specified in the SQL query.
#
# If you call a complicated SQL query which spans multiple tables the columns specified by the
# SELECT will be attributes of the model, whether or not they are columns of the corresponding
# table.
#
# The +sql+ parameter is a full SQL query as a string. It will be called as is, there will be
# no database agnostic conversions performed. This should be a last resort because using, for example,
# MySQL specific terms will lock you to using that particular database engine or require you to
# change your call if you switch engines.
#
# ==== Examples
# # A simple SQL query spanning multiple tables
# Post.find_by_sql "SELECT p.title, c.author FROM posts p, comments c WHERE p.id = c.post_id"
# > [#<Post:0x36bff9c @attributes={"title"=>"Ruby Meetup", "first_name"=>"Quentin"}>, ...]
#
# # You can use the same string replacement techniques as you can with ActiveRecord#find
# Post.find_by_sql ["SELECT title FROM posts WHERE author = ? AND created > ?", author_id, start_date]
# > [#<Post:0x36bff9c @attributes={"first_name"=>"The Cheap Man Buys Twice"}>, ...]
def find_by_sql(sql, binds = [])
connection.select_all(sanitize_sql(sql), "#{name} Load", binds).collect! { |record| instantiate(record) }
end
# Creates an object (or multiple objects) and saves it to the database, if validations pass.
# The resulting object is returned whether the object was saved successfully to the database or not.
#
# The +attributes+ parameter can be either be a Hash or an Array of Hashes. These Hashes describe the
# attributes on the objects that are to be created.
#
# ==== Examples
# # Create a single new object
# User.create(:first_name => 'Jamie')
#
# # Create an Array of new objects
# User.create([{ :first_name => 'Jamie' }, { :first_name => 'Jeremy' }])
#
# # Create a single object and pass it into a block to set other attributes.
# User.create(:first_name => 'Jamie') do |u|
# u.is_admin = false
# end
#
# # Creating an Array of new objects using a block, where the block is executed for each object:
# User.create([{ :first_name => 'Jamie' }, { :first_name => 'Jeremy' }]) do |u|
# u.is_admin = false
# end
def create(attributes = nil, &block)
if attributes.is_a?(Array)
attributes.collect { |attr| create(attr, &block) }
else
object = new(attributes)
yield(object) if block_given?
object.save
object
end
end
# Returns the result of an SQL statement that should only include a COUNT(*) in the SELECT part.
# The use of this method should be restricted to complicated SQL queries that can't be executed
# using the ActiveRecord::Calculations class methods. Look into those before using this.
#
# ==== Parameters
#
# * +sql+ - An SQL statement which should return a count query from the database, see the example below.
#
# ==== Examples
#
# Product.count_by_sql "SELECT COUNT(*) FROM sales s, customers c WHERE s.customer_id = c.id"
def count_by_sql(sql)
sql = sanitize_conditions(sql)
connection.select_value(sql, "#{name} Count").to_i
end
# Attributes listed as readonly will be used to create a new record but update operations will
# ignore these fields.
def attr_readonly(*attributes)
self._attr_readonly = Set.new(attributes.map { |a| a.to_s }) + (self._attr_readonly || [])
end
# Returns an array of all the attributes that have been specified as readonly.
def readonly_attributes
self._attr_readonly
end
# If you have an attribute that needs to be saved to the database as an object, and retrieved as the same object,
# then specify the name of that attribute using this method and it will be handled automatically.
# The serialization is done through YAML. If +class_name+ is specified, the serialized object must be of that
# class on retrieval or SerializationTypeMismatch will be raised.
#
# ==== Parameters
#
# * +attr_name+ - The field name that should be serialized.
# * +class_name+ - Optional, class name that the object type should be equal to.
#
# ==== Example
# # Serialize a preferences attribute
# class User
# serialize :preferences
# end
def serialize(attr_name, class_name = Object)
coder = if [:load, :dump].all? { |x| class_name.respond_to?(x) }
class_name
else
Coders::YAMLColumn.new(class_name)
end
# merge new serialized attribute and create new hash to ensure that each class in inheritance hierarchy
# has its own hash of own serialized attributes
self.serialized_attributes = serialized_attributes.merge(attr_name.to_s => coder)
end
# Guesses the table name (in forced lower-case) based on the name of the class in the
# inheritance hierarchy descending directly from ActiveRecord::Base. So if the hierarchy
# looks like: Reply < Message < ActiveRecord::Base, then Message is used
# to guess the table name even when called on Reply. The rules used to do the guess
# are handled by the Inflector class in Active Support, which knows almost all common
# English inflections. You can add new inflections in config/initializers/inflections.rb.
#
# Nested classes are given table names prefixed by the singular form of
# the parent's table name. Enclosing modules are not considered.
#
# ==== Examples
#
# class Invoice < ActiveRecord::Base; end;
# file class table_name
# invoice.rb Invoice invoices
#
# class Invoice < ActiveRecord::Base; class Lineitem < ActiveRecord::Base; end; end;
# file class table_name
# invoice.rb Invoice::Lineitem invoice_lineitems
#
# module Invoice; class Lineitem < ActiveRecord::Base; end; end;
# file class table_name
# invoice/lineitem.rb Invoice::Lineitem lineitems
#
# Additionally, the class-level +table_name_prefix+ is prepended and the
# +table_name_suffix+ is appended. So if you have "myapp_" as a prefix,
# the table name guess for an Invoice class becomes "myapp_invoices".
# Invoice::Lineitem becomes "myapp_invoice_lineitems".
#
# You can also overwrite this class method to allow for unguessable
# links, such as a Mouse class with a link to a "mice" table. Example:
#
# class Mouse < ActiveRecord::Base
# set_table_name "mice"
# end
def table_name
reset_table_name
end
# Returns a quoted version of the table name, used to construct SQL statements.
def quoted_table_name
@quoted_table_name ||= connection.quote_table_name(table_name)
end
# Computes the table name, (re)sets it internally, and returns it.
def reset_table_name #:nodoc:
self.table_name = compute_table_name
end
def full_table_name_prefix #:nodoc:
(parents.detect{ |p| p.respond_to?(:table_name_prefix) } || self).table_name_prefix
end
# Defines the column name for use with single table inheritance. Use
# <tt>set_inheritance_column</tt> to set a different value.
def inheritance_column
@inheritance_column ||= "type"
end
# Lazy-set the sequence name to the connection's default. This method
# is only ever called once since set_sequence_name overrides it.
def sequence_name #:nodoc:
reset_sequence_name
end
def reset_sequence_name #:nodoc:
default = connection.default_sequence_name(table_name, primary_key)
set_sequence_name(default)
default
end
# Sets the table name. If the value is nil or false then the value returned by the given
# block is used.
#
# class Project < ActiveRecord::Base
# set_table_name "project"
# end
def set_table_name(value = nil, &block)
@quoted_table_name = nil
define_attr_method :table_name, value, &block
@arel_table = Arel::Table.new(table_name, :engine => arel_engine)
@relation = Relation.new(self, arel_table)
end
alias :table_name= :set_table_name
# Sets the name of the inheritance column to use to the given value,
# or (if the value # is nil or false) to the value returned by the
# given block.
#
# class Project < ActiveRecord::Base
# set_inheritance_column do
# original_inheritance_column + "_id"
# end
# end
def set_inheritance_column(value = nil, &block)
define_attr_method :inheritance_column, value, &block
end
alias :inheritance_column= :set_inheritance_column
# Sets the name of the sequence to use when generating ids to the given
# value, or (if the value is nil or false) to the value returned by the
# given block. This is required for Oracle and is useful for any
# database which relies on sequences for primary key generation.
#
# If a sequence name is not explicitly set when using Oracle or Firebird,
# it will default to the commonly used pattern of: #{table_name}_seq
#
# If a sequence name is not explicitly set when using PostgreSQL, it
# will discover the sequence corresponding to your primary key for you.
#
# class Project < ActiveRecord::Base
# set_sequence_name "projectseq" # default would have been "project_seq"
# end
def set_sequence_name(value = nil, &block)
define_attr_method :sequence_name, value, &block
end
alias :sequence_name= :set_sequence_name
# Indicates whether the table associated with this class exists
def table_exists?
connection.table_exists?(table_name)
end
# Returns an array of column objects for the table associated with this class.
def columns
connection_pool.columns[table_name]
end
# Returns a hash of column objects for the table associated with this class.
def columns_hash
connection_pool.columns_hash[table_name]
end
# Returns an array of column names as strings.
def column_names
@column_names ||= columns.map { |column| column.name }
end
# Returns an array of column objects where the primary id, all columns ending in "_id" or "_count",
# and columns used for single table inheritance have been removed.
def content_columns
@content_columns ||= columns.reject { |c| c.primary || c.name =~ /(_id|_count)$/ || c.name == inheritance_column }
end
# Returns a hash of all the methods added to query each of the columns in the table with the name of the method as the key
# and true as the value. This makes it possible to do O(1) lookups in respond_to? to check if a given method for attribute
# is available.
def column_methods_hash #:nodoc:
@dynamic_methods_hash ||= column_names.inject(Hash.new(false)) do |methods, attr|
attr_name = attr.to_s
methods[attr.to_sym] = attr_name
methods["#{attr}=".to_sym] = attr_name
methods["#{attr}?".to_sym] = attr_name
methods["#{attr}_before_type_cast".to_sym] = attr_name
methods
end
end
# Resets all the cached information about columns, which will cause them
# to be reloaded on the next request.
#
# The most common usage pattern for this method is probably in a migration,
# when just after creating a table you want to populate it with some default
# values, eg:
#
# class CreateJobLevels < ActiveRecord::Migration
# def self.up
# create_table :job_levels do |t|
# t.integer :id
# t.string :name
#
# t.timestamps
# end
#
# JobLevel.reset_column_information
# %w{assistant executive manager director}.each do |type|
# JobLevel.create(:name => type)
# end
# end
#
# def self.down
# drop_table :job_levels
# end
# end
def reset_column_information
connection.clear_cache!
undefine_attribute_methods
connection_pool.clear_table_cache!(table_name) if table_exists?
@column_names = @content_columns = @dynamic_methods_hash = @inheritance_column = nil
@arel_engine = @relation = nil
end
def clear_cache! # :nodoc:
connection_pool.clear_cache!
end
def attribute_method?(attribute)
super || (table_exists? && column_names.include?(attribute.to_s.sub(/=$/, '')))
end
# Set the lookup ancestors for ActiveModel.
def lookup_ancestors #:nodoc:
klass = self
classes = [klass]
return classes if klass == ActiveRecord::Base
while klass != klass.base_class
classes << klass = klass.superclass
end
classes
end
# Set the i18n scope to overwrite ActiveModel.
def i18n_scope #:nodoc:
:activerecord
end
# True if this isn't a concrete subclass needing a STI type condition.
def descends_from_active_record?
if superclass.abstract_class?
superclass.descends_from_active_record?
else
superclass == Base || !columns_hash.include?(inheritance_column)
end
end
def finder_needs_type_condition? #:nodoc:
# This is like this because benchmarking justifies the strange :false stuff
:true == (@finder_needs_type_condition ||= descends_from_active_record? ? :false : :true)
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
def quote_value(value, column = nil) #:nodoc:
connection.quote(value,column)
end
# Used to sanitize objects before they're used in an SQL SELECT statement. Delegates to <tt>connection.quote</tt>.
def sanitize(object) #:nodoc:
connection.quote(object)
end
# Overwrite the default class equality method to provide support for association proxies.
def ===(object)
object.is_a?(self)
end
# Returns the base AR subclass that this class descends from. If A
# extends AR::Base, A.base_class will return A. If B descends from A
# through some arbitrarily deep hierarchy, B.base_class will return A.
#
# If B < A and C < B and if A is an abstract_class then both B.base_class
# and C.base_class would return B as the answer since A is an abstract_class.
def base_class
class_of_active_record_descendant(self)
end
# Set this to true if this is an abstract class (see <tt>abstract_class?</tt>).
attr_accessor :abstract_class
# Returns whether this class is an abstract class or not.
def abstract_class?
defined?(@abstract_class) && @abstract_class == true
end
def respond_to?(method_id, include_private = false)
if match = DynamicFinderMatch.match(method_id)
return true if all_attributes_exists?(match.attribute_names)
elsif match = DynamicScopeMatch.match(method_id)
return true if all_attributes_exists?(match.attribute_names)
end
super
end
def sti_name
store_full_sti_class ? name : name.demodulize
end
def arel_table
Arel::Table.new(table_name, arel_engine)
end
def arel_engine
@arel_engine ||= begin
if self == ActiveRecord::Base
ActiveRecord::Base
else
connection_handler.connection_pools[name] ? self : superclass.arel_engine
end
end
end
# Returns a scope for this class without taking into account the default_scope.
#
# class Post < ActiveRecord::Base
# default_scope :published => true
# end
#
# Post.all # Fires "SELECT * FROM posts WHERE published = true"
# Post.unscoped.all # Fires "SELECT * FROM posts"
#
# This method also accepts a block meaning that all queries inside the block will
# not use the default_scope:
#
# Post.unscoped {
# limit(10) # Fires "SELECT * FROM posts LIMIT 10"
# }
#
# It is recommended to use block form of unscoped because chaining unscoped with <tt>scope</tt>
# does not work. Assuming that <tt>published</tt> is a <tt>scope</tt> following two statements are same.
#
# Post.unscoped.published
# Post.published
def unscoped #:nodoc:
block_given? ? relation.scoping { yield } : relation
end
def scoped_methods #:nodoc:
key = :"#{self}_scoped_methods"
Thread.current[key] = Thread.current[key].presence || self.default_scoping.dup
end
def before_remove_const #:nodoc:
reset_scoped_methods
end
# Specifies how the record is loaded by +Marshal+.
#
# +_load+ sets an instance variable for each key in the hash it takes as input.
# Override this method if you require more complex marshalling.
def _load(data)
record = allocate
record.init_with(Marshal.load(data))
record
end
# Finder methods must instantiate through this method to work with the
# single-table inheritance model that makes it possible to create
# objects of different types from the same table.
def instantiate(record) # :nodoc:
model = find_sti_class(record[inheritance_column]).allocate
model.init_with('attributes' => record)
model
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
def find_sti_class(type_name)
if type_name.blank? || !columns_hash.include?(inheritance_column)
self
else
begin
if store_full_sti_class
ActiveSupport::Dependencies.constantize(type_name)
else
compute_type(type_name)
end
rescue NameError
raise SubclassNotFound,
"The single-table inheritance mechanism failed to locate the subclass: '#{type_name}'. " +
"This error is raised because the column '#{inheritance_column}' is reserved for storing the class in case of inheritance. " +
"Please rename this column if you didn't intend it to be used for storing the inheritance class " +
"or overwrite #{name}.inheritance_column to use another column for that information."
end
end
end
def construct_finder_arel(options = {}, scope = nil)
relation = options.is_a?(Hash) ? unscoped.apply_finder_options(options) : options
relation = scope.merge(relation) if scope
relation
end
def type_condition
sti_column = arel_table[inheritance_column.to_sym]
sti_names = ([self] + descendants).map { |model| model.sti_name }
sti_column.in(sti_names)
end
# Guesses the table name, but does not decorate it with prefix and suffix information.
def undecorated_table_name(class_name = base_class.name)
table_name = class_name.to_s.demodulize.underscore
table_name = table_name.pluralize if pluralize_table_names
table_name
end
# Computes and returns a table name according to default conventions.
def compute_table_name
base = base_class
if self == base
# Nested classes are prefixed with singular parent table name.
if parent < ActiveRecord::Base && !parent.abstract_class?
contained = parent.table_name
contained = contained.singularize if parent.pluralize_table_names
contained << '_'
end
"#{full_table_name_prefix}#{contained}#{undecorated_table_name(name)}#{table_name_suffix}"
else
# STI subclasses always use their superclass' table.
base.table_name
end
end
# Enables dynamic finders like <tt>User.find_by_user_name(user_name)</tt> and
# <tt>User.scoped_by_user_name(user_name). Refer to Dynamic attribute-based finders
# section at the top of this file for more detailed information.
#
# It's even possible to use all the additional parameters to +find+. For example, the
# full interface for +find_all_by_amount+ is actually <tt>find_all_by_amount(amount, options)</tt>.
#
# Each dynamic finder using <tt>scoped_by_*</tt> is also defined in the class after it
# is first invoked, so that future attempts to use it do not run through method_missing.
def method_missing(method_id, *arguments, &block)
if match = DynamicFinderMatch.match(method_id)
attribute_names = match.attribute_names
super unless all_attributes_exists?(attribute_names)
if match.finder?
options = arguments.extract_options!
relation = options.any? ? construct_finder_arel(options, current_scoped_methods) : scoped
relation.send :find_by_attributes, match, attribute_names, *arguments
elsif match.instantiator?
scoped.send :find_or_instantiator_by_attributes, match, attribute_names, *arguments, &block
end
elsif match = DynamicScopeMatch.match(method_id)
attribute_names = match.attribute_names
super unless all_attributes_exists?(attribute_names)
if match.scope?
self.class_eval <<-METHOD, __FILE__, __LINE__ + 1
def self.#{method_id}(*args) # def self.scoped_by_user_name_and_password(*args)
attributes = Hash[[:#{attribute_names.join(',:')}].zip(args)] # attributes = Hash[[:user_name, :password].zip(args)]
#
scoped(:conditions => attributes) # scoped(:conditions => attributes)
end # end
METHOD
send(method_id, *arguments)
end
else
super
end
end
# Similar in purpose to +expand_hash_conditions_for_aggregates+.
def expand_attribute_names_for_aggregates(attribute_names)
attribute_names.map { |attribute_name|
unless (aggregation = reflect_on_aggregation(attribute_name.to_sym)).nil?
aggregate_mapping(aggregation).map do |field_attr, _|
field_attr.to_sym
end
else
attribute_name.to_sym
end
}.flatten
end
def all_attributes_exists?(attribute_names)
(expand_attribute_names_for_aggregates(attribute_names) -
column_methods_hash.keys).empty?
end
protected
# with_scope lets you apply options to inner block incrementally. It takes a hash and the keys must be
# <tt>:find</tt> or <tt>:create</tt>. <tt>:find</tt> parameter is <tt>Relation</tt> while
# <tt>:create</tt> parameters are an attributes hash.
#
# class Article < ActiveRecord::Base
# def self.create_with_scope
# with_scope(:find => where(:blog_id => 1), :create => { :blog_id => 1 }) do
# find(1) # => SELECT * from articles WHERE blog_id = 1 AND id = 1
# a = create(1)
# a.blog_id # => 1
# end
# end
# end
#
# In nested scopings, all previous parameters are overwritten by the innermost rule, with the exception of
# <tt>where</tt>, <tt>includes</tt>, and <tt>joins</tt> operations in <tt>Relation</tt>, which are merged.
#
# <tt>joins</tt> operations are uniqued so multiple scopes can join in the same table without table aliasing
# problems. If you need to join multiple tables, but still want one of the tables to be uniqued, use the
# array of strings format for your joins.
#
# class Article < ActiveRecord::Base
# def self.find_with_scope
# with_scope(:find => where(:blog_id => 1).limit(1), :create => { :blog_id => 1 }) do
# with_scope(:find => limit(10)) do
# all # => SELECT * from articles WHERE blog_id = 1 LIMIT 10
# end
# with_scope(:find => where(:author_id => 3)) do
# all # => SELECT * from articles WHERE blog_id = 1 AND author_id = 3 LIMIT 1
# end
# end
# end
# end
#
# You can ignore any previous scopings by using the <tt>with_exclusive_scope</tt> method.
#
# class Article < ActiveRecord::Base
# def self.find_with_exclusive_scope
# with_scope(:find => where(:blog_id => 1).limit(1)) do
# with_exclusive_scope(:find => limit(10)) do
# all # => SELECT * from articles LIMIT 10
# end
# end
# end
# end
#
# *Note*: the +:find+ scope also has effect on update and deletion methods, like +update_all+ and +delete_all+.
def with_scope(method_scoping = {}, action = :merge, &block)
method_scoping = method_scoping.method_scoping if method_scoping.respond_to?(:method_scoping)
if method_scoping.is_a?(Hash)
# Dup first and second level of hash (method and params).
method_scoping = method_scoping.dup
method_scoping.each do |method, params|
method_scoping[method] = params.dup unless params == true
end
method_scoping.assert_valid_keys([ :find, :create ])
relation = construct_finder_arel(method_scoping[:find] || {})
if current_scoped_methods && current_scoped_methods.create_with_value && method_scoping[:create]
scope_for_create = if action == :merge
current_scoped_methods.create_with_value.merge(method_scoping[:create])
else
method_scoping[:create]
end
relation = relation.create_with(scope_for_create)
else
scope_for_create = method_scoping[:create]
scope_for_create ||= current_scoped_methods.create_with_value if current_scoped_methods
relation = relation.create_with(scope_for_create) if scope_for_create
end
method_scoping = relation
end
method_scoping = current_scoped_methods.merge(method_scoping) if current_scoped_methods && action == :merge
self.scoped_methods << method_scoping
begin
yield
ensure
self.scoped_methods.pop
end
end
# Works like with_scope, but discards any nested properties.
def with_exclusive_scope(method_scoping = {}, &block)
if method_scoping.values.any? { |e| e.is_a?(ActiveRecord::Relation) }
raise ArgumentError, <<-MSG
New finder API can not be used with_exclusive_scope. You can either call unscoped to get an anonymous scope not bound to the default_scope:
User.unscoped.where(:active => true)
Or call unscoped with a block:
User.unscoped do
User.where(:active => true).all
end
MSG
end
with_scope(method_scoping, :overwrite, &block)
end
# Sets the default options for the model. The format of the
# <tt>options</tt> argument is the same as in find.
#
# class Person < ActiveRecord::Base
# default_scope order('last_name, first_name')
# end
#
# <tt>default_scope</tt> is also applied while creating/building a record. It is not
# applied while updating a record.
#
# class Article < ActiveRecord::Base
# default_scope where(:published => true)
# end
#
# Article.new.published # => true
# Article.create.published # => true
def default_scope(options = {})
reset_scoped_methods
default_scoping = self.default_scoping.dup
self.default_scoping = default_scoping << construct_finder_arel(options, default_scoping.pop)
end
def current_scoped_methods #:nodoc:
method = scoped_methods.last
if method.respond_to?(:call)
relation.scoping { method.call }
else
method
end
end
def reset_scoped_methods #:nodoc:
Thread.current[:"#{self}_scoped_methods"] = nil
end
# Returns the class type of the record using the current module as a prefix. So descendants of
# MyApp::Business::Account would appear as MyApp::Business::AccountSubclass.
def compute_type(type_name)
if type_name.match(/^::/)
# If the type is prefixed with a scope operator then we assume that
# the type_name is an absolute reference.
ActiveSupport::Dependencies.constantize(type_name)
else
# Build a list of candidates to search for
candidates = []
name.scan(/::|$/) { candidates.unshift "#{$`}::#{type_name}" }
candidates << type_name
candidates.each do |candidate|
begin
constant = ActiveSupport::Dependencies.constantize(candidate)
return constant if candidate == constant.to_s
rescue NameError => e
# We don't want to swallow NoMethodError < NameError errors
raise e unless e.instance_of?(NameError)
rescue ArgumentError
end
end
raise NameError, "uninitialized constant #{candidates.first}"
end
end
# Returns the class descending directly from ActiveRecord::Base or an
# abstract class, if any, in the inheritance hierarchy.
def class_of_active_record_descendant(klass)
if klass.superclass == Base || klass.superclass.abstract_class?
klass
elsif klass.superclass.nil?
raise ActiveRecordError, "#{name} doesn't belong in a hierarchy descending from ActiveRecord"
else
class_of_active_record_descendant(klass.superclass)
end
end
# Accepts an array, hash, or string of SQL conditions and sanitizes
# them into a valid SQL fragment for a WHERE clause.
# ["name='%s' and group_id='%s'", "foo'bar", 4] returns "name='foo''bar' and group_id='4'"
# { :name => "foo'bar", :group_id => 4 } returns "name='foo''bar' and group_id='4'"
# "name='foo''bar' and group_id='4'" returns "name='foo''bar' and group_id='4'"
def sanitize_sql_for_conditions(condition, table_name = self.table_name)
return nil if condition.blank?
case condition
when Array; sanitize_sql_array(condition)
when Hash; sanitize_sql_hash_for_conditions(condition, table_name)
else condition
end
end
alias_method :sanitize_sql, :sanitize_sql_for_conditions
# Accepts an array, hash, or string of SQL conditions and sanitizes
# them into a valid SQL fragment for a SET clause.
# { :name => nil, :group_id => 4 } returns "name = NULL , group_id='4'"
def sanitize_sql_for_assignment(assignments)
case assignments
when Array; sanitize_sql_array(assignments)
when Hash; sanitize_sql_hash_for_assignment(assignments)
else assignments
end
end
def aggregate_mapping(reflection)
mapping = reflection.options[:mapping] || [reflection.name, reflection.name]
mapping.first.is_a?(Array) ? mapping : [mapping]
end
# Accepts a hash of SQL conditions and replaces those attributes
# that correspond to a +composed_of+ relationship with their expanded
# aggregate attribute values.
# Given:
# class Person < ActiveRecord::Base
# composed_of :address, :class_name => "Address",
# :mapping => [%w(address_street street), %w(address_city city)]
# end
# Then:
# { :address => Address.new("813 abc st.", "chicago") }
# # => { :address_street => "813 abc st.", :address_city => "chicago" }
def expand_hash_conditions_for_aggregates(attrs)
expanded_attrs = {}
attrs.each do |attr, value|
unless (aggregation = reflect_on_aggregation(attr.to_sym)).nil?
mapping = aggregate_mapping(aggregation)
mapping.each do |field_attr, aggregate_attr|
if mapping.size == 1 && !value.respond_to?(aggregate_attr)
expanded_attrs[field_attr] = value
else
expanded_attrs[field_attr] = value.send(aggregate_attr)
end
end
else
expanded_attrs[attr] = value
end
end
expanded_attrs
end
# Sanitizes a hash of attribute/value pairs into SQL conditions for a WHERE clause.
# { :name => "foo'bar", :group_id => 4 }
# # => "name='foo''bar' and group_id= 4"
# { :status => nil, :group_id => [1,2,3] }
# # => "status IS NULL and group_id IN (1,2,3)"
# { :age => 13..18 }
# # => "age BETWEEN 13 AND 18"
# { 'other_records.id' => 7 }
# # => "`other_records`.`id` = 7"
# { :other_records => { :id => 7 } }
# # => "`other_records`.`id` = 7"
# And for value objects on a composed_of relationship:
# { :address => Address.new("123 abc st.", "chicago") }
# # => "address_street='123 abc st.' and address_city='chicago'"
def sanitize_sql_hash_for_conditions(attrs, default_table_name = self.table_name)
attrs = expand_hash_conditions_for_aggregates(attrs)
table = Arel::Table.new(self.table_name, :engine => arel_engine, :as => default_table_name)
viz = Arel::Visitors.for(arel_engine)
PredicateBuilder.build_from_hash(arel_engine, attrs, table).map { |b|
viz.accept b
}.join(' AND ')
end
alias_method :sanitize_sql_hash, :sanitize_sql_hash_for_conditions
# Sanitizes a hash of attribute/value pairs into SQL conditions for a SET clause.
# { :status => nil, :group_id => 1 }
# # => "status = NULL , group_id = 1"
def sanitize_sql_hash_for_assignment(attrs)
attrs.map do |attr, value|
"#{connection.quote_column_name(attr)} = #{quote_bound_value(value)}"
end.join(', ')
end
# Accepts an array of conditions. The array has each value
# sanitized and interpolated into the SQL statement.
# ["name='%s' and group_id='%s'", "foo'bar", 4] returns "name='foo''bar' and group_id='4'"
def sanitize_sql_array(ary)
statement, *values = ary
if values.first.is_a?(Hash) && statement =~ /:\w+/
replace_named_bind_variables(statement, values.first)
elsif statement.include?('?')
replace_bind_variables(statement, values)
elsif statement.blank?
statement
else
statement % values.collect { |value| connection.quote_string(value.to_s) }
end
end
alias_method :sanitize_conditions, :sanitize_sql
def replace_bind_variables(statement, values) #:nodoc:
raise_if_bind_arity_mismatch(statement, statement.count('?'), values.size)
bound = values.dup
c = connection
statement.gsub('?') { quote_bound_value(bound.shift, c) }
end
def replace_named_bind_variables(statement, bind_vars) #:nodoc:
statement.gsub(/(:?):([a-zA-Z]\w*)/) do
if $1 == ':' # skip postgresql casts
$& # return the whole match
elsif bind_vars.include?(match = $2.to_sym)
quote_bound_value(bind_vars[match])
else
raise PreparedStatementInvalid, "missing value for :#{match} in #{statement}"
end
end
end
def expand_range_bind_variables(bind_vars) #:nodoc:
expanded = []
bind_vars.each do |var|
next if var.is_a?(Hash)
if var.is_a?(Range)
expanded << var.first
expanded << var.last
else
expanded << var
end
end
expanded
end
def quote_bound_value(value, c = connection) #:nodoc:
if value.respond_to?(:map) && !value.acts_like?(:string)
if value.respond_to?(:empty?) && value.empty?
c.quote(nil)
else
value.map { |v| c.quote(v) }.join(',')
end
else
c.quote(value)
end
end
def raise_if_bind_arity_mismatch(statement, expected, provided) #:nodoc:
unless expected == provided
raise PreparedStatementInvalid, "wrong number of bind variables (#{provided} for #{expected}) in: #{statement}"
end
end
def encode_quoted_value(value) #:nodoc:
quoted_value = connection.quote(value)
quoted_value = "'#{quoted_value[1..-2].gsub(/\'/, "\\\\'")}'" if quoted_value.include?("\\\'") # (for ruby mode) "
quoted_value
end
end
public
# 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.
def initialize(attributes = nil)
@attributes = attributes_from_column_definition
@association_cache = {}
@aggregation_cache = {}
@attributes_cache = {}
@new_record = true
@readonly = false
@destroyed = false
@marked_for_destruction = false
@previously_changed = {}
@changed_attributes = {}
ensure_proper_type
set_serialized_attributes
populate_with_current_scope_attributes
self.attributes = attributes unless attributes.nil?
result = yield self if block_given?
run_callbacks :initialize
result
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 # => { 'id' => nil, ... }
def encode_with(coder)
coder['attributes'] = attributes
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 = coder['attributes']
set_serialized_attributes
@attributes_cache, @previously_changed, @changed_attributes = {}, {}, {}
@association_cache = {}
@aggregation_cache = {}
@readonly = @destroyed = @marked_for_destruction = false
@new_record = false
run_callbacks :find
run_callbacks :initialize
end
# Specifies how the record is dumped by +Marshal+.
#
# +_dump+ emits a marshalled hash which has been passed to +encode_with+. Override this
# method if you require more complex marshalling.
def _dump(level)
dump = {}
encode_with(dump)
Marshal.dump(dump)
end
# Returns a String, which Action Pack uses for constructing an URL to this
# object. The default implementation returns this record's id as a String,
# or nil if this record's unsaved.
#
# For example, suppose that you have a User model, and that you have a
# <tt>resources :users</tt> route. Normally, +user_path+ will
# construct a path with the user object's 'id' in it:
#
# user = User.find_by_name('Phusion')
# user_path(user) # => "/users/1"
#
# You can override +to_param+ in your model to make +user_path+ construct
# a path using the user's name instead of the user's id:
#
# class User < ActiveRecord::Base
# def to_param # overridden
# name
# end
# end
#
# user = User.find_by_name('Phusion')
# user_path(user) # => "/users/Phusion"
def to_param
# We can't use alias_method here, because method 'id' optimizes itself on the fly.
id && id.to_s # Be sure to stringify the id for routes
end
# Returns a cache key that can be used to identify this record.
#
# ==== Examples
#
# Product.new.cache_key # => "products/new"
# Product.find(5).cache_key # => "products/5" (updated_at not available)
# Person.find(5).cache_key # => "people/5-20071224150000" (updated_at available)
def cache_key
case
when new_record?
"#{self.class.model_name.cache_key}/new"
when timestamp = self[:updated_at]
"#{self.class.model_name.cache_key}/#{id}-#{timestamp.to_s(:number)}"
else
"#{self.class.model_name.cache_key}/#{id}"
end
end
def quoted_id #:nodoc:
quote_value(id, column_for_attribute(self.class.primary_key))
end
# Returns true if the given attribute is in the attributes hash
def has_attribute?(attr_name)
@attributes.has_key?(attr_name.to_s)
end
# Returns an array of names for the attributes available on this object.
def attribute_names
@attributes.keys
end
# Allows you to set all the attributes at once by passing in a hash with keys
# matching the attribute names (which again matches the column names).
#
# If +guard_protected_attributes+ is true (the default), then sensitive
# attributes can be protected from this form of mass-assignment by using
# the +attr_protected+ macro. Or you can alternatively specify which
# attributes *can* be accessed with the +attr_accessible+ macro. Then all the
# attributes not included in that won't be allowed to be mass-assigned.
#
# class User < ActiveRecord::Base
# attr_protected :is_admin
# end
#
# user = User.new
# user.attributes = { :username => 'Phusion', :is_admin => true }
# user.username # => "Phusion"
# user.is_admin? # => false
#
# user.send(:attributes=, { :username => 'Phusion', :is_admin => true }, false)
# user.is_admin? # => true
def attributes=(new_attributes, guard_protected_attributes = true)
return unless new_attributes.is_a?(Hash)
attributes = new_attributes.stringify_keys
multi_parameter_attributes = []
attributes = sanitize_for_mass_assignment(attributes) if guard_protected_attributes
attributes.each do |k, v|
if k.include?("(")
multi_parameter_attributes << [ k, v ]
elsif respond_to?("#{k}=")
send("#{k}=", v)
else
raise(UnknownAttributeError, "unknown attribute: #{k}")
end
end
assign_multiparameter_attributes(multi_parameter_attributes)
end
# Returns a hash of all the attributes with their names as keys and the values of the attributes as values.
def attributes
Hash[@attributes.map { |name, _| [name, read_attribute(name)] }]
end
# Returns an <tt>#inspect</tt>-like string for the value of the
# attribute +attr_name+. String attributes are elided after 50
# characters, and Date and Time attributes are returned in the
# <tt>:db</tt> format. Other attributes return the value of
# <tt>#inspect</tt> without modification.
#
# person = Person.create!(:name => "David Heinemeier Hansson " * 3)
#
# person.attribute_for_inspect(:name)
# # => '"David Heinemeier Hansson David Heinemeier Hansson D..."'
#
# person.attribute_for_inspect(:created_at)
# # => '"2009-01-12 04:48:57"'
def attribute_for_inspect(attr_name)
value = read_attribute(attr_name)
if value.is_a?(String) && value.length > 50
"#{value[0..50]}...".inspect
elsif value.is_a?(Date) || value.is_a?(Time)
%("#{value.to_s(:db)}")
else
value.inspect
end
end
# Returns true if the specified +attribute+ has been set by the user or by a database load and is neither
# nil nor empty? (the latter only applies to objects that respond to empty?, most notably Strings).
def attribute_present?(attribute)
!_read_attribute(attribute).blank?
end
# Returns the column object for the named attribute.
def column_for_attribute(name)
self.class.columns_hash[name.to_s]
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)
comparison_object.equal?(self) ||
comparison_object.instance_of?(self.class) &&
id.present? &&
comparison_object.id == id
end
# Delegates to ==
def eql?(comparison_object)
self == comparison_object
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) ]
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
# Backport dup from 1.9 so that initialize_dup() gets called
unless Object.respond_to?(:initialize_dup)
def dup # :nodoc:
copy = super
copy.initialize_dup(self)
copy
end
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).
def initialize_dup(other)
cloned_attributes = other.clone_attributes(:read_attribute_before_type_cast)
cloned_attributes.delete(self.class.primary_key)
@attributes = cloned_attributes
_run_after_initialize_callbacks if respond_to?(:_run_after_initialize_callbacks)
@changed_attributes = {}
attributes_from_column_definition.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
clear_timestamp_attributes
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 contents of the record as a nicely formatted string.
def inspect
attributes_as_nice_string = self.class.column_names.collect { |name|
if has_attribute?(name)
"#{name}: #{attribute_for_inspect(name)}"
end
}.compact.join(", ")
"#<#{self.class} #{attributes_as_nice_string}>"
end
protected
def clone_attributes(reader_method = :read_attribute, attributes = {})
attribute_names.each do |name|
attributes[name] = clone_attribute_value(reader_method, name)
end
attributes
end
def clone_attribute_value(reader_method, attribute_name)
value = send(reader_method, attribute_name)
value.duplicable? ? value.clone : value
rescue TypeError, NoMethodError
value
end
private
def set_serialized_attributes
(@attributes.keys & self.class.serialized_attributes.keys).each do |key|
coder = self.class.serialized_attributes[key]
@attributes[key] = coder.load @attributes[key]
end
end
# Sets the attribute used for single table inheritance to this class name if this is not the
# ActiveRecord::Base descendant.
# Considering the hierarchy Reply < Message < ActiveRecord::Base, this makes it possible to
# do Reply.new without having to set <tt>Reply[Reply.inheritance_column] = "Reply"</tt> yourself.
# No such attribute would be set for objects of the Message class in that example.
def ensure_proper_type
unless self.class.descends_from_active_record?
write_attribute(self.class.inheritance_column, self.class.sti_name)
end
end
# The primary key and inheritance column can never be set by mass-assignment for security reasons.
def self.attributes_protected_by_default
default = [ primary_key, inheritance_column ]
default << 'id' unless primary_key.eql? 'id'
default
end
# Returns a copy of the attributes hash where all the values have been safely quoted for use in
# an Arel insert/update method.
def arel_attributes_values(include_primary_key = true, include_readonly_attributes = true, attribute_names = @attributes.keys)
attrs = {}
klass = self.class
arel_table = klass.arel_table
attribute_names.each do |name|
if (column = column_for_attribute(name)) && (include_primary_key || !column.primary)
if include_readonly_attributes || (!include_readonly_attributes && !self.class.readonly_attributes.include?(name))
value = if coder = klass.serialized_attributes[name]
coder.dump @attributes[name]
else
# FIXME: we need @attributes to be used consistently.
# If the values stored in @attributes were already type
# casted, this code could be simplified
read_attribute(name)
end
attrs[arel_table[name]] = value
end
end
end
attrs
end
# Quote strings appropriately for SQL statements.
def quote_value(value, column = nil)
self.class.connection.quote(value, column)
end
# Instantiates objects for all attribute classes that needs more than one constructor parameter. This is done
# by calling new on the column type or aggregation type (through composed_of) object with these parameters.
# So having the pairs written_on(1) = "2004", written_on(2) = "6", written_on(3) = "24", will instantiate
# written_on (a date type) with Date.new("2004", "6", "24"). You can also specify a typecast character in the
# parentheses to have the parameters typecasted before they're used in the constructor. Use i for Fixnum,
# f for Float, s for String, and a for Array. If all the values for a given attribute are empty, the
# attribute will be set to nil.
def assign_multiparameter_attributes(pairs)
execute_callstack_for_multiparameter_attributes(
extract_callstack_for_multiparameter_attributes(pairs)
)
end
def instantiate_time_object(name, values)
if self.class.send(:create_time_zone_conversion_attribute?, name, column_for_attribute(name))
Time.zone.local(*values)
else
Time.time_with_datetime_fallback(@@default_timezone, *values)
end
end
def execute_callstack_for_multiparameter_attributes(callstack)
errors = []
callstack.each do |name, values_with_empty_parameters|
begin
klass = (self.class.reflect_on_aggregation(name.to_sym) || column_for_attribute(name)).klass
# in order to allow a date to be set without a year, we must keep the empty values.
# Otherwise, we wouldn't be able to distinguish it from a date with an empty day.
values = values_with_empty_parameters.reject { |v| v.nil? }
if values.empty?
send(name + "=", nil)
else
value = if Time == klass
instantiate_time_object(name, values)
elsif Date == klass
begin
values = values_with_empty_parameters.collect do |v| v.nil? ? 1 : v end
Date.new(*values)
rescue ArgumentError => ex # if Date.new raises an exception on an invalid date
instantiate_time_object(name, values).to_date # we instantiate Time object and convert it back to a date thus using Time's logic in handling invalid dates
end
else
klass.new(*values)
end
send(name + "=", value)
end
rescue => ex
errors << AttributeAssignmentError.new("error on assignment #{values.inspect} to #{name}", ex, name)
end
end
unless errors.empty?
raise MultiparameterAssignmentErrors.new(errors), "#{errors.size} error(s) on assignment of multiparameter attributes"
end
end
def extract_callstack_for_multiparameter_attributes(pairs)
attributes = { }
for pair in pairs
multiparameter_name, value = pair
attribute_name = multiparameter_name.split("(").first
attributes[attribute_name] = [] unless attributes.include?(attribute_name)
parameter_value = value.empty? ? nil : type_cast_attribute_value(multiparameter_name, value)
attributes[attribute_name] << [ find_parameter_position(multiparameter_name), parameter_value ]
end
attributes.each { |name, values| attributes[name] = values.sort_by{ |v| v.first }.collect { |v| v.last } }
end
def type_cast_attribute_value(multiparameter_name, value)
multiparameter_name =~ /\([0-9]*([if])\)/ ? value.send("to_" + $1) : value
end
def find_parameter_position(multiparameter_name)
multiparameter_name.scan(/\(([0-9]*).*\)/).first.first
end
# Returns a comma-separated pair list, like "key1 = val1, key2 = val2".
def comma_pair_list(hash)
hash.map { |k,v| "#{k} = #{v}" }.join(", ")
end
def quote_columns(quoter, hash)
Hash[hash.map { |name, value| [quoter.quote_column_name(name), value] }]
end
def quoted_comma_pair_list(quoter, hash)
comma_pair_list(quote_columns(quoter, hash))
end
def convert_number_column_value(value)
if value == false
0
elsif value == true
1
elsif value.is_a?(String) && value.blank?
nil
else
value
end
end
def populate_with_current_scope_attributes
if scope = self.class.send(:current_scoped_methods)
create_with = scope.scope_for_create
create_with.each { |att,value|
respond_to?("#{att}=") && send("#{att}=", value)
}
end
end
# Clear attributes and changed_attributes
def clear_timestamp_attributes
all_timestamp_attributes_in_model.each do |attribute_name|
self[attribute_name] = nil
changed_attributes.delete(attribute_name)
end
end
end
Base.class_eval do
include ActiveRecord::Persistence
extend ActiveModel::Naming
extend QueryCache::ClassMethods
extend ActiveSupport::Benchmarkable
extend ActiveSupport::DescendantsTracker
include ActiveModel::Conversion
include Validations
extend CounterCache
include Locking::Optimistic, Locking::Pessimistic
include AttributeMethods
include AttributeMethods::Read, AttributeMethods::Write, AttributeMethods::BeforeTypeCast, AttributeMethods::Query
include AttributeMethods::PrimaryKey
include AttributeMethods::TimeZoneConversion
include AttributeMethods::Dirty
include ActiveModel::MassAssignmentSecurity
include Callbacks, ActiveModel::Observing, Timestamp
include Associations, AssociationPreload, NamedScope
include ActiveModel::SecurePassword
# AutosaveAssociation needs to be included before Transactions, because we want
# #save_with_autosave_associations to be wrapped inside a transaction.
include AutosaveAssociation, NestedAttributes
include Aggregations, Transactions, Reflection, Serialization
NilClass.add_whiner(self) if NilClass.respond_to?(:add_whiner)
# Returns the value of the attribute identified by <tt>attr_name</tt> after it has been typecast (for example,
# "2004-12-12" in a data column is cast to a date object, like Date.new(2004, 12, 12)).
# (Alias for the protected read_attribute method).
alias [] read_attribute
# Updates the attribute identified by <tt>attr_name</tt> with the specified +value+.
# (Alias for the protected write_attribute method).
alias []= write_attribute
public :[], :[]=
end
end
# TODO: Remove this and make it work with LAZY flag
require 'active_record/connection_adapters/abstract_adapter'
ActiveSupport.run_load_hooks(:active_record, ActiveRecord::Base)