require 'yaml'
require 'set'
module ActiveRecord #:nodoc:
# Generic ActiveRecord exception class.
class ActiveRecordError < StandardError
end
# Raised when the single-table inheritance mechanism failes to locate the subclass
# (for example due to improper usage of column that +inheritance_column+ points to).
class SubclassNotFound < ActiveRecordError #:nodoc:
end
# Raised when object assigned to association is of incorrect type.
#
# Example:
#
# class Ticket < ActiveRecord::Base
# has_many :patches
# end
#
# class Patch < ActiveRecord::Base
# belongs_to :ticket
# end
#
# and somewhere in the code:
#
# @ticket.patches << Comment.new(:content => "Please attach tests to your patch.")
# @ticket.save
class AssociationTypeMismatch < ActiveRecordError
end
# Raised when unserialized object's type mismatches one specified for serializable field.
class SerializationTypeMismatch < ActiveRecordError
end
# Raised when adapter not specified on connection (or configuration file config/database.yml misses adapter field).
class AdapterNotSpecified < ActiveRecordError
end
# Raised when ActiveRecord cannot find database adapter specified in config/database.yml or programmatically.
class AdapterNotFound < ActiveRecordError
end
# Raised when connection to the database could not been established (for example when connection= is given a nil object).
class ConnectionNotEstablished < ActiveRecordError
end
# Raised when ActiveRecord cannot find record by given id or set of ids.
class RecordNotFound < ActiveRecordError
end
# Raised by ActiveRecord::Base.save! and ActiveRecord::Base.create! methods when record cannot be
# saved because record is invalid.
class RecordNotSaved < ActiveRecordError
end
# Raised when SQL statement cannot be executed by the database (for example, it's often the case for MySQL when Ruby driver used is too old).
class StatementInvalid < ActiveRecordError
end
# Raised when number of bind variables in statement given to :condition key (for example, when using +find+ method)
# does not match number of expected variables.
#
# Example:
#
# Location.find :all, :conditions => ["lat = ? AND lng = ?", 53.7362]
#
# in example above two placeholders are given but only one variable to fill them.
class PreparedStatementInvalid < ActiveRecordError
end
# Raised on attempt to save stale record. Record is stale when it's being saved in another query after
# instantiation, for example, when two users edit the same wiki page and one starts editing and saves
# the page before the other.
#
# Read more about optimistic locking in +ActiveRecord::Locking+ module RDoc.
class StaleObjectError < ActiveRecordError
end
# Raised when association is being configured improperly or
# user tries to use offset and limit together with has_many or has_and_belongs_to_many associations.
class ConfigurationError < ActiveRecordError
end
# Raised on attempt to update record that is instantiated as read only.
class ReadOnlyRecord < ActiveRecordError
end
# Used by ActiveRecord transaction mechanism to distinguish rollback from other exceptional situations.
# You can use it to roll your transaction back explicitly in the block passed to +transaction+ method.
class Rollback < ActiveRecordError
end
# Raised when attribute has a name reserved by ActiveRecord (when attribute has name of one of ActiveRecord instance methods).
class DangerousAttributeError < ActiveRecordError
end
# Raised when you've tried to access a column which wasn't
# loaded by your finder. Typically this is because :select
# has been specified
class MissingAttributeError < NoMethodError
end
class AttributeAssignmentError < ActiveRecordError #:nodoc:
attr_reader :exception, :attribute
def initialize(message, exception, attribute)
@exception = exception
@attribute = attribute
@message = message
end
end
class MultiparameterAssignmentErrors < ActiveRecordError #:nodoc:
attr_reader :errors
def initialize(errors)
@errors = errors
end
end
# 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/README.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)
# find(:first, :conditions => "user_name = '#{user_name}' AND password = '#{password}'")
# end
#
# def self.authenticate_safely(user_name, password)
# find(:first, :conditions => [ "user_name = ? AND password = ?", user_name, password ])
# end
#
# def self.authenticate_safely_simply(user_name, password)
# find(:first, :conditions => { :user_name => user_name, :password => password })
# end
# end
#
# The authenticate_unsafely method inserts the parameters directly into the query and is thus susceptible to SQL-injection
# attacks if the user_name and +password+ parameters come directly from an HTTP request. The authenticate_safely and
# authenticate_safely_simply both will sanitize the user_name 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.find(:first, :conditions => [
# "id = :id AND name = :name AND division = :division AND created_at > :accounting_date",
# { :id => 3, :name => "37signals", :division => "First", :accounting_date => '2005-01-01' }
# ])
#
# Similarly, a simple hash without a statement will generate conditions based on equality with the SQL AND
# operator. For instance:
#
# Student.find(:all, :conditions => { :first_name => "Harvey", :status => 1 })
# Student.find(:all, :conditions => params[:student])
#
# A range may be used in the hash to use the SQL BETWEEN operator:
#
# Student.find(:all, :conditions => { :grade => 9..12 })
#
# An array may be used in the hash to use the SQL IN operator:
#
# Student.find(:all, :conditions => { :grade => [9,11,12] })
#
# == 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 read_attribute(attr_name) and write_attribute(attr_name, value) to actually change things.
# Example:
#
# class Song < ActiveRecord::Base
# # Uses an integer of seconds to hold the length of the song
#
# def length=(minutes)
# write_attribute(:length, minutes * 60)
# end
#
# def length
# read_attribute(:length) / 60
# end
# end
#
# You can alternatively use self[:attribute]=(value) and self[:attribute] instead of write_attribute(:attribute, value) and
# read_attribute(:attribute) as a shorter form.
#
# == 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 name attribute has a name? 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 _before_type_cast accessors that all attributes have. For example, if your Account model
# has a balance attribute, you can call account.balance_before_type_cast or account.id_before_type_cast.
#
# 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 find_by_ or find_all_by_, so you get finders like Person.find_by_user_name,
# Person.find_all_by_last_name, Payment.find_by_transaction_id. So instead of writing
# Person.find(:first, :conditions => ["user_name = ?", user_name]), you just do Person.find_by_user_name(user_name).
# And instead of writing Person.find(:all, :conditions => ["last_name = ?", last_name]), you just do Person.find_all_by_last_name(last_name).
#
# It's also possible to use multiple attributes in the same find by separating them with "_and_", so you get finders like
# Person.find_by_user_name_and_password or even Payment.find_by_purchaser_and_state_and_country. So instead of writing
# Person.find(:first, :conditions => ["user_name = ? AND password = ?", user_name, password]), you just do
# Person.find_by_user_name_and_password(user_name, password).
#
# It's even possible to use all the additional parameters to find. For example, the full interface for Payment.find_all_by_amount
# is actually Payment.find_all_by_amount(amount, options). And the full interface to Person.find_by_user_name is
# actually Person.find_by_user_name(user_name, options). So you could call Payment.find_all_by_amount(50, :order => "created_on").
#
# The same dynamic finder style can be used to create the object if it doesn't already exist. This dynamic finder is called with
# find_or_create_by_ 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. For example:
#
# # 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 find_or_initialize_by_ finder if you want to return a new record without saving it first. Protected attributes won't be setted unless they are given in a block. For example:
#
# # No 'Winter' tag exists
# winter = Tag.find_or_initialize_by_name("Winter")
# winter.new_record? # true
#
# 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. For example:
#
# 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.
#
# == 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. Example:
#
# 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
# descendent of a class not in the hierarchy. Example:
#
# class User < ActiveRecord::Base
# serialize :preferences, Hash
# end
#
# user = User.create(:preferences => %w( one two three ))
# User.find(user.id).preferences # raises SerializationTypeMismatch
#
# == 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 Base.inheritance_column). 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 Firm.create(:name => "37signals"), this record will be saved in the companies table with type = "Firm". You can then
# fetch this row again using Company.find(:first, "name = '37signals'") 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 Course.establish_connection
# and Course *and all 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 establish_connection didn't include an
# :adapter key.
# * +AdapterNotFound+ -- the :adapter key used in establish_connection 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 establish_connection 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.
# * +StatementInvalid+ -- the database server rejected the SQL statement. The precise error is added in the message.
# Either the record with the given ID doesn't exist or the record didn't meet the additional restrictions.
# * +MultiparameterAssignmentErrors+ -- collection of errors that occurred during a mass assignment using the
# +attributes=+ 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 +attributes=+ 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 Base.logger= which will then be used by all
# instances in the current object space.
class Base
# 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
def self.inherited(child) #:nodoc:
@@subclasses[self] ||= []
@@subclasses[self] << child
super
end
def self.reset_subclasses #:nodoc:
nonreloadables = []
subclasses.each do |klass|
unless Dependencies.autoloaded? klass
nonreloadables << klass
next
end
klass.instance_variables.each { |var| klass.send(:remove_instance_variable, var) }
klass.instance_methods(false).each { |m| klass.send :undef_method, m }
end
@@subclasses = {}
nonreloadables.each { |klass| (@@subclasses[klass.superclass] ||= []) << klass }
end
@@subclasses = {}
cattr_accessor :configurations, :instance_writer => false
@@configurations = {}
# 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
# 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.
cattr_accessor :table_name_prefix, :instance_writer => false
@@table_name_prefix = ""
# 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.
cattr_accessor :table_name_suffix, :instance_writer => false
@@table_name_suffix = ""
# 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
# Determines whether to use ANSI codes to colorize the logging statements committed by the connection adapter. These colors
# make it much easier to overview things during debugging (when used through a reader like +tail+ and on a black background), but
# may complicate matters if you use software like syslog. This is true, by default.
cattr_accessor :colorize_logging, :instance_writer => false
@@colorize_logging = true
# 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
# Determines whether to use a connection for each thread, or a single shared connection for all threads.
# Defaults to false. Set to true if you're writing a threaded application.
cattr_accessor :allow_concurrency, :instance_writer => false
@@allow_concurrency = false
# 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
class << self # Class methods
# Find operates with four different retrieval approaches:
#
# * Find by id: This can either be a specific id (1), a list of ids (1, 5, 6), or an array of ids ([5, 6, 10]).
# If no record can be found for all of the listed ids, then RecordNotFound will be raised.
# * Find first: This will return the first record matched by the options used. These options can either be specific
# conditions or merely an order. If no record can be matched, nil is returned.
# * Find last: This will return the last record matched by the options used. These options can either be specific
# conditions or merely an order. If no record can be matched, nil is returned.
# * Find all: This will return all the records matched by the options used. If no records are found, an empty array is returned.
#
# All approaches accept an options hash as their last parameter. The options are:
#
# * :conditions: An SQL fragment like "administrator = 1" or [ "user_name = ?", username ]. See conditions in the intro.
# * :order: An SQL fragment like "created_at DESC, name".
# * :group: An attribute name by which the result should be grouped. Uses the GROUP BY SQL-clause.
# * :limit: An integer determining the limit on the number of rows that should be returned.
# * :offset: An integer determining the offset from where the rows should be fetched. So at 5, it would skip rows 0 through 4.
# * :joins: Either an SQL fragment for additional joins like "LEFT JOIN comments ON comments.post_id = id" (rarely needed)
# or named associations in the same form used for the :include option, which will perform an INNER JOIN on the associated table(s).
# If the value is a string, then the records will be returned read-only since they will have attributes that do not correspond to the table's columns.
# Pass :readonly => false to override.
# * :include: Names associations that should be loaded alongside using LEFT OUTER JOINs. The symbols named refer
# to already defined associations. See eager loading under Associations.
# * :select: By default, this is * as in SELECT * FROM, but can be changed if you, for example, want to do a join but not
# include the joined columns.
# * :from: By default, this is the table name of the class, but can be changed to an alternate table name (or even the name
# of a database view).
# * :readonly: Mark the returned records read-only so they cannot be saved or updated.
# * :lock: An SQL fragment like "FOR UPDATE" or "LOCK IN SHARE MODE".
# :lock => true gives connection's default exclusive lock, usually "FOR UPDATE".
#
# Examples for find by id:
# Person.find(1) # returns the object for ID = 1
# Person.find(1, 2, 6) # returns an array for objects with IDs in (1, 2, 6)
# Person.find([7, 17]) # returns an array for objects with IDs in (7, 17)
# Person.find([1]) # returns an array for the object with ID = 1
# Person.find(1, :conditions => "administrator = 1", :order => "created_on DESC")
#
# Note that returned records may not be in the same order as the ids you
# provide since database rows are unordered. Give an explicit :order
# to ensure the results are sorted.
#
# Examples for find first:
# Person.find(:first) # returns the first object fetched by SELECT * FROM people
# Person.find(:first, :conditions => [ "user_name = ?", user_name])
# Person.find(:first, :order => "created_on DESC", :offset => 5)
#
# Examples for find last:
# Person.find(:last) # returns the last object fetched by SELECT * FROM people
# Person.find(:last, :conditions => [ "user_name = ?", user_name])
# Person.find(:last, :order => "created_on DESC", :offset => 5)
#
# Examples for find all:
# Person.find(:all) # returns an array of objects for all the rows fetched by SELECT * FROM people
# Person.find(:all, :conditions => [ "category IN (?)", categories], :limit => 50)
# Person.find(:all, :conditions => { :friends => ["Bob", "Steve", "Fred"] }
# Person.find(:all, :offset => 10, :limit => 10)
# Person.find(:all, :include => [ :account, :friends ])
# Person.find(:all, :group => "category")
#
# Example for find with a lock. Imagine two concurrent transactions:
# each will read person.visits == 2, add 1 to it, and save, resulting
# in two saves of person.visits = 3. By locking the row, the second
# transaction has to wait until the first is finished; we get the
# expected person.visits == 4.
# Person.transaction do
# person = Person.find(1, :lock => true)
# person.visits += 1
# person.save!
# end
def find(*args)
options = args.extract_options!
validate_find_options(options)
set_readonly_option!(options)
case args.first
when :first then find_initial(options)
when :last then find_last(options)
when :all then find_every(options)
else find_from_ids(args, options)
end
end
# This is an alias for find(:first). You can pass in all the same arguments to this method as you can
# to find(:first)
def first(*args)
find(:first, *args)
end
# This is an alias for find(:last). You can pass in all the same arguments to this method as you can
# to find(:last)
def last(*args)
find(:last, *args)
end
#
# 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 +Product.find_by_sql+ 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"
# > [#"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]
# > [#"The Cheap Man Buys Twice"}>, ...]
def find_by_sql(sql)
connection.select_all(sanitize_sql(sql), "#{name} Load").collect! { |record| instantiate(record) }
end
# Checks whether a record exists in the database that matches conditions given. These conditions
# can either be a single integer representing a primary key id to be found, or a condition to be
# matched like using ActiveRecord#find.
#
# The +id_or_conditions+ parameter can be an Integer or a String if you want to search the primary key
# column of the table for a matching id, or if you're looking to match against a condition you can use
# an Array or a Hash.
#
# Possible gotcha: You can't pass in a condition as a string e.g. "name = 'Jamie'", this would be
# sanitized and then queried against the primary key column as "id = 'name = \'Jamie"
#
# ==== Examples
# Person.exists?(5)
# Person.exists?('5')
# Person.exists?(:name => "David")
# Person.exists?(['name LIKE ?', "%#{query}%"])
def exists?(id_or_conditions)
connection.select_all(
construct_finder_sql(
:select => "#{quoted_table_name}.#{primary_key}",
:conditions => expand_id_conditions(id_or_conditions),
:limit => 1
),
"#{name} Exists"
).size > 0
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'}])
def create(attributes = nil)
if attributes.is_a?(Array)
attributes.collect { |attr| create(attr) }
else
object = new(attributes)
object.save
object
end
end
# Updates 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.
#
# ==== Options
#
# +id+ This should be the id or an array of ids to be updated
# +attributes+ This should be a Hash of attributes to be set on the object, or an array of Hashes.
#
# ==== Examples
#
# # Updating one record:
# Person.update(15, {:user_name => 'Samuel', :group => 'expert'})
#
# # Updating multiple records:
# people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy"} }
# Person.update(people.keys, people.values)
def update(id, attributes)
if id.is_a?(Array)
idx = -1
id.collect { |one_id| idx += 1; update(one_id, attributes[idx]) }
else
object = find(id)
object.update_attributes(attributes)
object
end
end
# Delete an object (or multiple objects) where the +id+ given matches the primary_key. A SQL +DELETE+ command
# is executed on the database which means that no callbacks are fired off running this. This is an efficient method
# of deleting records that don't need cleaning up after or other actions to be taken.
#
# Objects are _not_ instantiated with this method.
#
# ==== Options
#
# +id+ Can be either an Integer or an Array of Integers
#
# ==== Examples
#
# # Delete a single object
# Todo.delete(1)
#
# # Delete multiple objects
# todos = [1,2,3]
# Todo.delete(todos)
def delete(id)
delete_all([ "#{connection.quote_column_name(primary_key)} IN (?)", id ])
end
# Destroy an object (or multiple objects) that has the given id, the object is instantiated first,
# therefore all callbacks and filters are fired off before the object is deleted. This method is
# less efficient than ActiveRecord#delete but allows cleanup methods and other actions to be run.
#
# This essentially finds the object (or multiple objects) with the given id, creates a new object
# from the attributes, and then calls destroy on it.
#
# ==== Options
#
# +id+ Can be either an Integer or an Array of Integers
#
# ==== Examples
#
# # Destroy a single object
# Todo.destroy(1)
#
# # Destroy multiple objects
# todos = [1,2,3]
# Todo.destroy(todos)
def destroy(id)
if id.is_a?(Array)
id.map { |one_id| destroy(one_id) }
else
find(id).destroy
end
end
# Updates all records with details given if they match a set of conditions supplied, limits and order can
# also be supplied.
#
# ==== Options
#
# +updates+ A String of column and value pairs that will be set on any records that match conditions
# +conditions+ An SQL fragment like "administrator = 1" or [ "user_name = ?", username ].
# See conditions in the intro for more info.
# +options+ Additional options are :limit and/or :order, see the examples for usage.
#
# ==== Examples
#
# # Update all billing objects with the 3 different attributes given
# Billing.update_all( "category = 'authorized', approved = 1, author = 'David'" )
#
# # Update records that match our conditions
# Billing.update_all( "author = 'David'", "title LIKE '%Rails%'" )
#
# # Update records that match our conditions but limit it to 5 ordered by date
# Billing.update_all( "author = 'David'", "title LIKE '%Rails%'",
# :order => 'created_at', :limit => 5 )
def update_all(updates, conditions = nil, options = {})
sql = "UPDATE #{quoted_table_name} SET #{sanitize_sql_for_assignment(updates)} "
scope = scope(:find)
add_conditions!(sql, conditions, scope)
add_order!(sql, options[:order], nil)
add_limit!(sql, options, nil)
connection.update(sql, "#{name} Update")
end
# Destroys the records matching +conditions+ by instantiating each record and calling the destroy method.
# This means at least 2*N database queries to destroy N records, so avoid destroy_all if you are deleting
# many records. If you want to simply delete records without worrying about dependent associations or
# callbacks, use the much faster +delete_all+ method instead.
#
# ==== Options
#
# +conditions+ Conditions are specified the same way as with +find+ method.
#
# ==== Example
#
# Person.destroy_all "last_login < '2004-04-04'"
#
# This loads and destroys each person one by one, including its dependent associations and before_ and
# after_destroy callbacks.
def destroy_all(conditions = nil)
find(:all, :conditions => conditions).each { |object| object.destroy }
end
# Deletes the records matching +conditions+ without instantiating the records first, and hence not
# calling the destroy method and invoking callbacks. This is a single SQL query, much more efficient
# than destroy_all.
#
# ==== Options
#
# +conditions+ Conditions are specified the same way as with +find+ method.
#
# ==== Example
#
# Post.delete_all "person_id = 5 AND (category = 'Something' OR category = 'Else')"
#
# This deletes the affected posts all at once with a single DELETE query. If you need to destroy dependent
# associations or call your before_ or after_destroy callbacks, use the +destroy_all+ method instead.
def delete_all(conditions = nil)
sql = "DELETE FROM #{quoted_table_name} "
add_conditions!(sql, conditions, scope(:find))
connection.delete(sql, "#{name} Delete all")
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.
#
# ==== Options
#
# +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
# A generic "counter updater" implementation, intended primarily to be
# used by increment_counter and decrement_counter, but which may also
# be useful on its own. It simply does a direct SQL update for the record
# with the given ID, altering the given hash of counters by the amount
# given by the corresponding value:
#
# ==== Options
#
# +id+ The id of the object you wish to update a counter on
# +counters+ An Array of Hashes containing the names of the fields
# to update as keys and the amount to update the field by as
# values
#
# ==== Examples
#
# # For the Post with id of 5, decrement the comment_count by 1, and
# # increment the action_count by 1
# Post.update_counters 5, :comment_count => -1, :action_count => 1
# # Executes the following SQL:
# # UPDATE posts
# # SET comment_count = comment_count - 1,
# # action_count = action_count + 1
# # WHERE id = 5
def update_counters(id, counters)
updates = counters.inject([]) { |list, (counter_name, increment)|
sign = increment < 0 ? "-" : "+"
list << "#{connection.quote_column_name(counter_name)} = #{connection.quote_column_name(counter_name)} #{sign} #{increment.abs}"
}.join(", ")
update_all(updates, "#{connection.quote_column_name(primary_key)} = #{quote_value(id)}")
end
# Increment a number field by one, usually representing a count.
#
# This is used for caching aggregate values, so that they don't need to be computed every time.
# For example, a DiscussionBoard may cache post_count and comment_count otherwise every time the board is
# shown it would have to run an SQL query to find how many posts and comments there are.
#
# ==== Options
#
# +counter_name+ The name of the field that should be incremented
# +id+ The id of the object that should be incremented
#
# ==== Examples
#
# # Increment the post_count column for the record with an id of 5
# DiscussionBoard.increment_counter(:post_count, 5)
def increment_counter(counter_name, id)
update_counters(id, counter_name => 1)
end
# Decrement a number field by one, usually representing a count.
#
# This works the same as increment_counter but reduces the column value by 1 instead of increasing it.
#
# ==== Options
#
# +counter_name+ The name of the field that should be decremented
# +id+ The id of the object that should be decremented
#
# ==== Examples
#
# # Decrement the post_count column for the record with an id of 5
# DiscussionBoard.decrement_counter(:post_count, 5)
def decrement_counter(counter_name, id)
update_counters(id, counter_name => -1)
end
# Attributes named in this macro are protected from mass-assignment, such as new(attributes) and
# attributes=(attributes). Their assignment will simply be ignored. Instead, you can use the direct writer
# methods to do assignment. This is meant to protect sensitive attributes from being overwritten by URL/form hackers. Example:
#
# class Customer < ActiveRecord::Base
# attr_protected :credit_rating
# end
#
# customer = Customer.new("name" => David, "credit_rating" => "Excellent")
# customer.credit_rating # => nil
# customer.attributes = { "description" => "Jolly fellow", "credit_rating" => "Superb" }
# customer.credit_rating # => nil
#
# customer.credit_rating = "Average"
# customer.credit_rating # => "Average"
#
# To start from an all-closed default and enable attributes as needed, have a look at attr_accessible.
def attr_protected(*attributes)
write_inheritable_attribute("attr_protected", Set.new(attributes.map(&:to_s)) + (protected_attributes || []))
end
# Returns an array of all the attributes that have been protected from mass-assignment.
def protected_attributes # :nodoc:
read_inheritable_attribute("attr_protected")
end
# Similar to the attr_protected macro, this protects attributes of your model from mass-assignment,
# such as new(attributes) and attributes=(attributes)
# however, it does it in the opposite way. This locks all attributes and only allows access to the
# attributes specified. Assignment to attributes not in this list will be ignored and need to be set
# using the direct writer methods instead. This is meant to protect sensitive attributes from being
# overwritten by URL/form hackers. If you'd rather start from an all-open default and restrict
# attributes as needed, have a look at attr_protected.
#
# ==== Options
#
# *attributes A comma separated list of symbols that represent columns _not_ to be protected
#
# ==== Examples
#
# class Customer < ActiveRecord::Base
# attr_accessible :name, :nickname
# end
#
# customer = Customer.new(:name => "David", :nickname => "Dave", :credit_rating => "Excellent")
# customer.credit_rating # => nil
# customer.attributes = { :name => "Jolly fellow", :credit_rating => "Superb" }
# customer.credit_rating # => nil
#
# customer.credit_rating = "Average"
# customer.credit_rating # => "Average"
def attr_accessible(*attributes)
write_inheritable_attribute("attr_accessible", Set.new(attributes.map(&:to_s)) + (accessible_attributes || []))
end
# Returns an array of all the attributes that have been made accessible to mass-assignment.
def accessible_attributes # :nodoc:
read_inheritable_attribute("attr_accessible")
end
# Attributes listed as readonly can be set for a new record, but will be ignored in database updates afterwards.
def attr_readonly(*attributes)
write_inheritable_attribute("attr_readonly", Set.new(attributes.map(&:to_s)) + (readonly_attributes || []))
end
# Returns an array of all the attributes that have been specified as readonly.
def readonly_attributes
read_inheritable_attribute("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.
#
# ==== Options
#
# +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)
serialized_attributes[attr_name.to_s] = class_name
end
# Returns a hash of all the attributes that have been specified for serialization as keys and their class restriction as values.
def serialized_attributes
read_inheritable_attribute("attr_serialized") or write_inheritable_attribute("attr_serialized", {})
end
# Guesses the table name (in forced lower-case) based on the name of the class in the inheritance hierarchy descending
# directly from ActiveRecord. So if the hierarchy looks like: Reply < Message < ActiveRecord, 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
def reset_table_name #:nodoc:
base = base_class
name =
# STI subclasses always use their superclass' table.
unless self == base
base.table_name
else
# 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
name = "#{table_name_prefix}#{contained}#{undecorated_table_name(base.name)}#{table_name_suffix}"
end
set_table_name(name)
name
end
# Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
# primary_key_prefix_type setting, though.
def primary_key
reset_primary_key
end
def reset_primary_key #:nodoc:
key = get_primary_key(base_class.name)
set_primary_key(key)
key
end
def get_primary_key(base_name) #:nodoc:
key = 'id'
case primary_key_prefix_type
when :table_name
key = Inflector.foreign_key(base_name, false)
when :table_name_with_underscore
key = Inflector.foreign_key(base_name)
end
key
end
# Defines the column name for use with single table inheritance
# -- can be set in subclasses like so: self.inheritance_column = "type_id"
def inheritance_column
@inheritance_column ||= "type".freeze
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 to use to the given value, or (if the value
# is nil or false) to the value returned by the given block.
#
# Example:
#
# class Project < ActiveRecord::Base
# set_table_name "project"
# end
def set_table_name(value = nil, &block)
define_attr_method :table_name, value, &block
end
alias :table_name= :set_table_name
# Sets the name of the primary key column to use to the given value,
# or (if the value is nil or false) to the value returned by the given
# block.
#
# Example:
#
# class Project < ActiveRecord::Base
# set_primary_key "sysid"
# end
def set_primary_key(value = nil, &block)
define_attr_method :primary_key, value, &block
end
alias :primary_key= :set_primary_key
# 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.
#
# Example:
#
# 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.
#
# Example:
#
# 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
# Turns the +table_name+ back into a class name following the reverse rules of +table_name+.
def class_name(table_name = table_name) # :nodoc:
# remove any prefix and/or suffix from the table name
class_name = table_name[table_name_prefix.length..-(table_name_suffix.length + 1)].camelize
class_name = class_name.singularize if pluralize_table_names
class_name
end
# Indicates whether the table associated with this class exists
def table_exists?
if connection.respond_to?(:tables)
connection.tables.include? table_name
else
# if the connection adapter hasn't implemented tables, there are two crude tests that can be
# used - see if getting column info raises an error, or if the number of columns returned is zero
begin
reset_column_information
columns.size > 0
rescue ActiveRecord::StatementInvalid
false
end
end
end
# Returns an array of column objects for the table associated with this class.
def columns
unless defined?(@columns) && @columns
@columns = connection.columns(table_name, "#{name} Columns")
@columns.each { |column| column.primary = column.name == primary_key }
end
@columns
end
# Returns a hash of column objects for the table associated with this class.
def columns_hash
@columns_hash ||= columns.inject({}) { |hash, column| hash[column.name] = column; hash }
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.
def reset_column_information
generated_methods.each { |name| undef_method(name) }
@column_names = @columns = @columns_hash = @content_columns = @dynamic_methods_hash = @generated_methods = @inheritance_column = nil
end
def reset_column_information_and_inheritable_attributes_for_all_subclasses#:nodoc:
subclasses.each { |klass| klass.reset_inheritable_attributes; klass.reset_column_information }
end
# Transforms attribute key names into a more humane format, such as "First name" instead of "first_name". Example:
# Person.human_attribute_name("first_name") # => "First name"
# Deprecated in favor of just calling "first_name".humanize
def human_attribute_name(attribute_key_name) #:nodoc:
attribute_key_name.humanize
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 connection.quote.
def sanitize(object) #:nodoc:
connection.quote(object)
end
# Log and benchmark multiple statements in a single block. Example:
#
# Project.benchmark("Creating project") do
# project = Project.create("name" => "stuff")
# project.create_manager("name" => "David")
# project.milestones << Milestone.find(:all)
# end
#
# The benchmark is only recorded if the current level of the logger is less than or equal to the log_level,
# which makes it easy to include benchmarking statements in production software that will remain inexpensive because
# the benchmark will only be conducted if the log level is low enough.
#
# The logging of the multiple statements is turned off unless use_silence is set to false.
def benchmark(title, log_level = Logger::DEBUG, use_silence = true)
if logger && logger.level <= log_level
result = nil
seconds = Benchmark.realtime { result = use_silence ? silence { yield } : yield }
logger.add(log_level, "#{title} (#{'%.5f' % seconds})")
result
else
yield
end
end
# Silences the logger for the duration of the block.
def silence
old_logger_level, logger.level = logger.level, Logger::ERROR if logger
yield
ensure
logger.level = old_logger_level if logger
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.
def base_class
class_of_active_record_descendant(self)
end
# Set this to true if this is an abstract class (see #abstract_class?).
attr_accessor :abstract_class
# Returns whether this class is a base AR class. If A is a base class and
# B descends from A, then B.base_class will return B.
def abstract_class?
defined?(@abstract_class) && @abstract_class == true
end
private
def find_initial(options)
options.update(:limit => 1) unless options[:include]
find_every(options).first
end
def find_last(options)
order = options[:order]
if order
order = reverse_sql_order(order)
elsif !scoped?(:find, :order)
order = "#{table_name}.#{primary_key} DESC"
end
if scoped?(:find, :order)
scoped_order = reverse_sql_order(scope(:find, :order))
scoped_methods.select { |s| s[:find].update(:order => scoped_order) }
end
find_initial(options.merge({ :order => order }))
end
def reverse_sql_order(order_query)
reversed_query = order_query.split(/,/).each { |s|
if s.match(/\s(asc|ASC)$/)
s.gsub!(/\s(asc|ASC)$/, ' DESC')
elsif s.match(/\s(desc|DESC)$/)
s.gsub!(/\s(desc|DESC)$/, ' ASC')
elsif !s.match(/\s(asc|ASC|desc|DESC)$/)
s.concat(' DESC')
end
}.join(',')
end
def find_every(options)
include_associations = merge_includes(scope(:find, :include), options[:include])
if include_associations.any? && references_eager_loaded_tables?(options)
records = find_with_associations(options)
else
records = find_by_sql(construct_finder_sql(options))
if include_associations.any?
preload_associations(records, include_associations)
end
end
records.each { |record| record.readonly! } if options[:readonly]
records
end
def find_from_ids(ids, options)
expects_array = ids.first.kind_of?(Array)
return ids.first if expects_array && ids.first.empty?
ids = ids.flatten.compact.uniq
case ids.size
when 0
raise RecordNotFound, "Couldn't find #{name} without an ID"
when 1
result = find_one(ids.first, options)
expects_array ? [ result ] : result
else
find_some(ids, options)
end
end
def find_one(id, options)
conditions = " AND (#{sanitize_sql(options[:conditions])})" if options[:conditions]
options.update :conditions => "#{quoted_table_name}.#{connection.quote_column_name(primary_key)} = #{quote_value(id,columns_hash[primary_key])}#{conditions}"
# Use find_every(options).first since the primary key condition
# already ensures we have a single record. Using find_initial adds
# a superfluous :limit => 1.
if result = find_every(options).first
result
else
raise RecordNotFound, "Couldn't find #{name} with ID=#{id}#{conditions}"
end
end
def find_some(ids, options)
conditions = " AND (#{sanitize_sql(options[:conditions])})" if options[:conditions]
ids_list = ids.map { |id| quote_value(id,columns_hash[primary_key]) }.join(',')
options.update :conditions => "#{quoted_table_name}.#{connection.quote_column_name(primary_key)} IN (#{ids_list})#{conditions}"
result = find_every(options)
# Determine expected size from limit and offset, not just ids.size.
expected_size =
if options[:limit] && ids.size > options[:limit]
options[:limit]
else
ids.size
end
# 11 ids with limit 3, offset 9 should give 2 results.
if options[:offset] && (ids.size - options[:offset] < expected_size)
expected_size = ids.size - options[:offset]
end
if result.size == expected_size
result
else
raise RecordNotFound, "Couldn't find all #{name.pluralize} with IDs (#{ids_list})#{conditions} (found #{result.size} results, but was looking for #{expected_size})"
end
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)
object =
if subclass_name = record[inheritance_column]
# No type given.
if subclass_name.empty?
allocate
else
# Ignore type if no column is present since it was probably
# pulled in from a sloppy join.
unless columns_hash.include?(inheritance_column)
allocate
else
begin
compute_type(subclass_name).allocate
rescue NameError
raise SubclassNotFound,
"The single-table inheritance mechanism failed to locate the subclass: '#{record[inheritance_column]}'. " +
"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 #{self.to_s}.inheritance_column to use another column for that information."
end
end
end
else
allocate
end
object.instance_variable_set("@attributes", record)
object.instance_variable_set("@attributes_cache", Hash.new)
if object.respond_to_without_attributes?(:after_find)
object.send(:callback, :after_find)
end
if object.respond_to_without_attributes?(:after_initialize)
object.send(:callback, :after_initialize)
end
object
end
# Nest the type name in the same module as this class.
# Bar is "MyApp::Business::Bar" relative to MyApp::Business::Foo
def type_name_with_module(type_name)
(/^::/ =~ type_name) ? type_name : "#{parent.name}::#{type_name}"
end
def construct_finder_sql(options)
scope = scope(:find)
sql = "SELECT #{(scope && scope[:select]) || options[:select] || (options[:joins] && quoted_table_name + '.*') || '*'} "
sql << "FROM #{(scope && scope[:from]) || options[:from] || quoted_table_name} "
add_joins!(sql, options, scope)
add_conditions!(sql, options[:conditions], scope)
add_group!(sql, options[:group], scope)
add_order!(sql, options[:order], scope)
add_limit!(sql, options, scope)
add_lock!(sql, options, scope)
sql
end
# Merges includes so that the result is a valid +include+
def merge_includes(first, second)
(safe_to_array(first) + safe_to_array(second)).uniq
end
# Merges conditions so that the result is a valid +condition+
def merge_conditions(*conditions)
segments = []
conditions.each do |condition|
unless condition.blank?
sql = sanitize_sql(condition)
segments << sql unless sql.blank?
end
end
"(#{segments.join(') AND (')})" unless segments.empty?
end
# Object#to_a is deprecated, though it does have the desired behavior
def safe_to_array(o)
case o
when NilClass
[]
when Array
o
else
[o]
end
end
def add_order!(sql, order, scope = :auto)
scope = scope(:find) if :auto == scope
scoped_order = scope[:order] if scope
if order
sql << " ORDER BY #{order}"
sql << ", #{scoped_order}" if scoped_order
else
sql << " ORDER BY #{scoped_order}" if scoped_order
end
end
def add_group!(sql, group, scope = :auto)
if group
sql << " GROUP BY #{group}"
else
scope = scope(:find) if :auto == scope
if scope && (scoped_group = scope[:group])
sql << " GROUP BY #{scoped_group}"
end
end
end
# The optional scope argument is for the current :find scope.
def add_limit!(sql, options, scope = :auto)
scope = scope(:find) if :auto == scope
if scope
options[:limit] ||= scope[:limit]
options[:offset] ||= scope[:offset]
end
connection.add_limit_offset!(sql, options)
end
# The optional scope argument is for the current :find scope.
# The :lock option has precedence over a scoped :lock.
def add_lock!(sql, options, scope = :auto)
scope = scope(:find) if :auto == scope
options = options.reverse_merge(:lock => scope[:lock]) if scope
connection.add_lock!(sql, options)
end
# The optional scope argument is for the current :find scope.
def add_joins!(sql, options, scope = :auto)
scope = scope(:find) if :auto == scope
[(scope && scope[:joins]), options[:joins]].each do |join|
case join
when Symbol, Hash, Array
join_dependency = ActiveRecord::Associations::ClassMethods::InnerJoinDependency.new(self, join, nil)
sql << " #{join_dependency.join_associations.collect { |assoc| assoc.association_join }.join} "
else
sql << " #{join} "
end
end
end
# Adds a sanitized version of +conditions+ to the +sql+ string. Note that the passed-in +sql+ string is changed.
# The optional scope argument is for the current :find scope.
def add_conditions!(sql, conditions, scope = :auto)
scope = scope(:find) if :auto == scope
conditions = [conditions]
conditions << scope[:conditions] if scope
conditions << type_condition if finder_needs_type_condition?
merged_conditions = merge_conditions(*conditions)
sql << "WHERE #{merged_conditions} " unless merged_conditions.blank?
end
def type_condition
quoted_inheritance_column = connection.quote_column_name(inheritance_column)
type_condition = subclasses.inject("#{quoted_table_name}.#{quoted_inheritance_column} = '#{name.demodulize}' ") do |condition, subclass|
condition << "OR #{quoted_table_name}.#{quoted_inheritance_column} = '#{subclass.name.demodulize}' "
end
" (#{type_condition}) "
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 = Inflector.underscore(Inflector.demodulize(class_name))
table_name = Inflector.pluralize(table_name) if pluralize_table_names
table_name
end
# Enables dynamic finders like find_by_user_name(user_name) and find_by_user_name_and_password(user_name, password) that are turned into
# find(:first, :conditions => ["user_name = ?", user_name]) and find(:first, :conditions => ["user_name = ? AND password = ?", user_name, password])
# respectively. Also works for find(:all) by using find_all_by_amount(50) that is turned into find(:all, :conditions => ["amount = ?", 50]).
#
# It's even possible to use all the additional parameters to find. For example, the full interface for find_all_by_amount
# is actually find_all_by_amount(amount, options).
#
# This also enables you to initialize a record if it is not found, such as find_or_initialize_by_amount(amount)
# or find_or_create_by_user_and_password(user, password).
#
# Each dynamic finder or initializer/creator 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)
if match = /^find_(all_by|by)_([_a-zA-Z]\w*)$/.match(method_id.to_s)
finder = determine_finder(match)
attribute_names = extract_attribute_names_from_match(match)
super unless all_attributes_exists?(attribute_names)
self.class_eval %{
def self.#{method_id}(*args)
options = args.extract_options!
attributes = construct_attributes_from_arguments([:#{attribute_names.join(',:')}], args)
finder_options = { :conditions => attributes }
validate_find_options(options)
set_readonly_option!(options)
if options[:conditions]
with_scope(:find => finder_options) do
ActiveSupport::Deprecation.silence { send(:#{finder}, options) }
end
else
ActiveSupport::Deprecation.silence { send(:#{finder}, options.merge(finder_options)) }
end
end
}, __FILE__, __LINE__
send(method_id, *arguments)
elsif match = /^find_or_(initialize|create)_by_([_a-zA-Z]\w*)$/.match(method_id.to_s)
instantiator = determine_instantiator(match)
attribute_names = extract_attribute_names_from_match(match)
super unless all_attributes_exists?(attribute_names)
self.class_eval %{
def self.#{method_id}(*args)
guard_protected_attributes = false
if args[0].is_a?(Hash)
guard_protected_attributes = true
attributes = args[0].with_indifferent_access
find_attributes = attributes.slice(*[:#{attribute_names.join(',:')}])
else
find_attributes = attributes = construct_attributes_from_arguments([:#{attribute_names.join(',:')}], args)
end
options = { :conditions => find_attributes }
set_readonly_option!(options)
record = find_initial(options)
if record.nil?
record = self.new { |r| r.send(:attributes=, attributes, guard_protected_attributes) }
#{'yield(record) if block_given?'}
#{'record.save' if instantiator == :create}
record
else
record
end
end
}, __FILE__, __LINE__
send(method_id, *arguments)
else
super
end
end
def determine_finder(match)
match.captures.first == 'all_by' ? :find_every : :find_initial
end
def determine_instantiator(match)
match.captures.first == 'initialize' ? :new : :create
end
def extract_attribute_names_from_match(match)
match.captures.last.split('_and_')
end
def construct_attributes_from_arguments(attribute_names, arguments)
attributes = {}
attribute_names.each_with_index { |name, idx| attributes[name] = arguments[idx] }
attributes
end
# Similar in purpose to +expand_hash_conditions_for_aggregates+.
def expand_attribute_names_for_aggregates(attribute_names)
expanded_attribute_names = []
attribute_names.each do |attribute_name|
unless (aggregation = reflect_on_aggregation(attribute_name.to_sym)).nil?
aggregate_mapping(aggregation).each do |field_attr, aggregate_attr|
expanded_attribute_names << field_attr
end
else
expanded_attribute_names << attribute_name
end
end
expanded_attribute_names
end
def all_attributes_exists?(attribute_names)
attribute_names = expand_attribute_names_for_aggregates(attribute_names)
attribute_names.all? { |name| column_methods_hash.include?(name.to_sym) }
end
def attribute_condition(argument)
case argument
when nil then "IS ?"
when Array, ActiveRecord::Associations::AssociationCollection then "IN (?)"
when Range then "BETWEEN ? AND ?"
else "= ?"
end
end
# Interpret Array and Hash as conditions and anything else as an id.
def expand_id_conditions(id_or_conditions)
case id_or_conditions
when Array, Hash then id_or_conditions
else sanitize_sql(primary_key => id_or_conditions)
end
end
# Defines an "attribute" method (like #inheritance_column or
# #table_name). A new (class) method will be created with the
# given name. If a value is specified, the new method will
# return that value (as a string). Otherwise, the given block
# will be used to compute the value of the method.
#
# The original method will be aliased, with the new name being
# prefixed with "original_". This allows the new method to
# access the original value.
#
# Example:
#
# class A < ActiveRecord::Base
# define_attr_method :primary_key, "sysid"
# define_attr_method( :inheritance_column ) do
# original_inheritance_column + "_id"
# end
# end
def define_attr_method(name, value=nil, &block)
sing = class << self; self; end
sing.send :alias_method, "original_#{name}", name
if block_given?
sing.send :define_method, name, &block
else
# use eval instead of a block to work around a memory leak in dev
# mode in fcgi
sing.class_eval "def #{name}; #{value.to_s.inspect}; end"
end
end
protected
# Scope parameters to method calls within the block. Takes a hash of method_name => parameters hash.
# method_name may be :find or :create. :find parameters may include the :conditions, :joins,
# :include, :offset, :limit, and :readonly options. :create parameters are an attributes hash.
#
# class Article < ActiveRecord::Base
# def self.create_with_scope
# with_scope(:find => { :conditions => "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
# :conditions and :include options in :find, which are merged.
#
# class Article < ActiveRecord::Base
# def self.find_with_scope
# with_scope(:find => { :conditions => "blog_id = 1", :limit => 1 }, :create => { :blog_id => 1 }) do
# with_scope(:find => { :limit => 10})
# find(:all) # => SELECT * from articles WHERE blog_id = 1 LIMIT 10
# end
# with_scope(:find => { :conditions => "author_id = 3" })
# find(: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 with_exclusive_scope method.
#
# class Article < ActiveRecord::Base
# def self.find_with_exclusive_scope
# with_scope(:find => { :conditions => "blog_id = 1", :limit => 1 }) do
# with_exclusive_scope(:find => { :limit => 10 })
# find(:all) # => SELECT * from articles LIMIT 10
# end
# end
# end
# end
def with_scope(method_scoping = {}, action = :merge, &block)
method_scoping = method_scoping.method_scoping if method_scoping.respond_to?(:method_scoping)
# Dup first and second level of hash (method and params).
method_scoping = method_scoping.inject({}) do |hash, (method, params)|
hash[method] = (params == true) ? params : params.dup
hash
end
method_scoping.assert_valid_keys([ :find, :create ])
if f = method_scoping[:find]
f.assert_valid_keys(VALID_FIND_OPTIONS)
set_readonly_option! f
end
# Merge scopings
if action == :merge && current_scoped_methods
method_scoping = current_scoped_methods.inject(method_scoping) do |hash, (method, params)|
case hash[method]
when Hash
if method == :find
(hash[method].keys + params.keys).uniq.each do |key|
merge = hash[method][key] && params[key] # merge if both scopes have the same key
if key == :conditions && merge
hash[method][key] = merge_conditions(params[key], hash[method][key])
elsif key == :include && merge
hash[method][key] = merge_includes(hash[method][key], params[key]).uniq
else
hash[method][key] = hash[method][key] || params[key]
end
end
else
hash[method] = params.merge(hash[method])
end
else
hash[method] = params
end
hash
end
end
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)
with_scope(method_scoping, :overwrite, &block)
end
def subclasses #:nodoc:
@@subclasses[self] ||= []
@@subclasses[self] + extra = @@subclasses[self].inject([]) {|list, subclass| list + subclass.subclasses }
end
# Test whether the given method and optional key are scoped.
def scoped?(method, key = nil) #:nodoc:
if current_scoped_methods && (scope = current_scoped_methods[method])
!key || scope.has_key?(key)
end
end
# Retrieve the scope for the given method and optional key.
def scope(method, key = nil) #:nodoc:
if current_scoped_methods && (scope = current_scoped_methods[method])
key ? scope[key] : scope
end
end
def thread_safe_scoped_methods #:nodoc:
scoped_methods = (Thread.current[:scoped_methods] ||= {})
scoped_methods[self] ||= []
end
def single_threaded_scoped_methods #:nodoc:
@scoped_methods ||= []
end
# pick up the correct scoped_methods version from @@allow_concurrency
if @@allow_concurrency
alias_method :scoped_methods, :thread_safe_scoped_methods
else
alias_method :scoped_methods, :single_threaded_scoped_methods
end
def current_scoped_methods #:nodoc:
scoped_methods.last
end
# Returns the class type of the record using the current module as a prefix. So descendents of
# MyApp::Business::Account would appear as MyApp::Business::AccountSubclass.
def compute_type(type_name)
modularized_name = type_name_with_module(type_name)
begin
class_eval(modularized_name, __FILE__, __LINE__)
rescue NameError
class_eval(type_name, __FILE__, __LINE__)
end
end
# Returns the class descending directly from ActiveRecord 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
# Returns the name of the class descending directly from ActiveRecord in the inheritance hierarchy.
def class_name_of_active_record_descendant(klass) #:nodoc:
klass.base_class.name
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)
case condition
when Array; sanitize_sql_array(condition)
when Hash; sanitize_sql_hash_for_conditions(condition)
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"
# 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)
attrs = expand_hash_conditions_for_aggregates(attrs)
conditions = attrs.map do |attr, value|
attr = attr.to_s
# Extract table name from qualified attribute names.
if attr.include?('.')
table_name, attr = attr.split('.', 2)
table_name = connection.quote_table_name(table_name)
else
table_name = quoted_table_name
end
"#{table_name}.#{connection.quote_column_name(attr)} #{attribute_condition(value)}"
end.join(' AND ')
replace_bind_variables(conditions, expand_range_bind_variables(attrs.values))
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) and statement =~ /:\w+/
replace_named_bind_variables(statement, values.first)
elsif statement.include?('?')
replace_bind_variables(statement, values)
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
statement.gsub('?') { quote_bound_value(bound.shift) }
end
def replace_named_bind_variables(statement, bind_vars) #:nodoc:
statement.gsub(/:([a-zA-Z]\w*)/) do
match = $1.to_sym
if bind_vars.include?(match)
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:
bind_vars.sum do |var|
if var.is_a?(Range)
[var.first, var.last]
else
[var]
end
end
end
def quote_bound_value(value) #:nodoc:
if value.respond_to?(:map) && !value.is_a?(String)
if value.respond_to?(:empty?) && value.empty?
connection.quote(nil)
else
value.map { |v| connection.quote(v) }.join(',')
end
else
connection.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
VALID_FIND_OPTIONS = [ :conditions, :include, :joins, :limit, :offset,
:order, :select, :readonly, :group, :from, :lock ]
def validate_find_options(options) #:nodoc:
options.assert_valid_keys(VALID_FIND_OPTIONS)
end
def set_readonly_option!(options) #:nodoc:
# Inherit :readonly from finder scope if set. Otherwise,
# if :joins is not blank then :readonly defaults to true.
unless options.has_key?(:readonly)
if scoped_readonly = scope(:find, :readonly)
options[:readonly] = scoped_readonly
elsif !options[:joins].blank? && !options[:select]
options[:readonly] = true
end
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
@attributes_cache = {}
@new_record = true
ensure_proper_type
self.attributes = attributes unless attributes.nil?
self.class.send(:scope, :create).each { |att,value| self.send("#{att}=", value) } if self.class.send(:scoped?, :create)
result = yield self if block_given?
callback(:after_initialize) if respond_to_without_attributes?(:after_initialize)
result
end
# A model instance's primary key is always available as model.id
# whether you name it the default 'id' or set it to something else.
def id
attr_name = self.class.primary_key
column = column_for_attribute(attr_name)
self.class.send(:define_read_method, :id, attr_name, column)
# now that the method exists, call it
self.send attr_name.to_sym
end
# Enables Active Record objects to be used as URL parameters in Action Pack automatically.
def to_param
# We can't use alias_method here, because method 'id' optimizes itself on the fly.
(id = self.id) ? id.to_s : nil # 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.name.tableize}/new"
when self[:updated_at]
"#{self.class.name.tableize}/#{id}-#{updated_at.to_s(:number)}"
else
"#{self.class.name.tableize}/#{id}"
end
end
def id_before_type_cast #:nodoc:
read_attribute_before_type_cast(self.class.primary_key)
end
def quoted_id #:nodoc:
quote_value(id, column_for_attribute(self.class.primary_key))
end
# Sets the primary ID.
def id=(value)
write_attribute(self.class.primary_key, value)
end
# Returns true if this object hasn't been saved yet -- that is, a record for the object doesn't exist yet.
def new_record?
defined?(@new_record) && @new_record
end
# * No record exists: Creates a new record with values matching those of the object attributes.
# * A record does exist: Updates the record with values matching those of the object attributes.
#
# Note: If your model specifies any validations then the method declaration dynamically
# changes to:
# save(perform_validation=true)
# Calling save(false) saves the model without running validations.
# See ActiveRecord::Validations for more information.
def save
create_or_update
end
# Attempts to save the record, but instead of just returning false if it couldn't happen, it raises a
# RecordNotSaved exception
def save!
create_or_update || raise(RecordNotSaved)
end
# Deletes the record in the database and freezes this instance to reflect that no changes should
# be made (since they can't be persisted).
def destroy
unless new_record?
connection.delete <<-end_sql, "#{self.class.name} Destroy"
DELETE FROM #{self.class.quoted_table_name}
WHERE #{connection.quote_column_name(self.class.primary_key)} = #{quoted_id}
end_sql
end
freeze
end
# Returns a clone of the record that hasn't been assigned an id yet and
# is treated as a new record. Note that this is a "shallow" clone:
# it copies the object's attributes only, not its associations.
# The extent of a "deep" clone is application-specific and is therefore
# left to the application to implement according to its need.
def clone
attrs = clone_attributes(:read_attribute_before_type_cast)
attrs.delete(self.class.primary_key)
record = self.class.new
record.send :instance_variable_set, '@attributes', attrs
record
end
# Returns an instance of the specified klass with the attributes of the current record. This is mostly useful in relation to
# single-table inheritance structures where you want a subclass to appear as the superclass. This can be used along with record
# identification in Action Pack to allow, say, Client < Company to do something like render :partial => @client.becomes(Company)
# to render that instance using the companies/company partial instead of clients/client.
#
# Note: The new instance will share a link to the same attributes as the original class. So any change to the attributes in either
# instance will affect the other.
def becomes(klass)
returning klass.new do |became|
became.instance_variable_set("@attributes", @attributes)
became.instance_variable_set("@attributes_cache", @attributes_cache)
became.instance_variable_set("@new_record", new_record?)
end
end
# Updates a single attribute and saves the record. This is especially useful for boolean flags on existing records.
# Note: This method is overwritten by the Validation module that'll make sure that updates made with this method
# aren't subjected to validation checks. Hence, attributes can be updated even if the full object isn't valid.
def update_attribute(name, value)
send(name.to_s + '=', value)
save
end
# Updates all the attributes from the passed-in Hash and saves the record. If the object is invalid, the saving will
# fail and false will be returned.
def update_attributes(attributes)
self.attributes = attributes
save
end
# Updates an object just like Base.update_attributes but calls save! instead of save so an exception is raised if the record is invalid.
def update_attributes!(attributes)
self.attributes = attributes
save!
end
# Initializes the +attribute+ to zero if nil and adds the value passed as +by+ (default is one). Only makes sense for number-based attributes. Returns self.
def increment(attribute, by = 1)
self[attribute] ||= 0
self[attribute] += by
self
end
# Increments the +attribute+ and saves the record.
# Note: Updates made with this method aren't subjected to validation checks
def increment!(attribute, by = 1)
increment(attribute, by).update_attribute(attribute, self[attribute])
end
# Initializes the +attribute+ to zero if nil and subtracts the value passed as +by+ (default is one). Only makes sense for number-based attributes. Returns self.
def decrement(attribute, by = 1)
self[attribute] ||= 0
self[attribute] -= by
self
end
# Decrements the +attribute+ and saves the record.
# Note: Updates made with this method aren't subjected to validation checks
def decrement!(attribute, by = 1)
decrement(attribute, by).update_attribute(attribute, self[attribute])
end
# Turns an +attribute+ that's currently true into false and vice versa. Returns self.
def toggle(attribute)
self[attribute] = !send("#{attribute}?")
self
end
# Toggles the +attribute+ and saves the record.
# Note: Updates made with this method aren't subjected to validation checks
def toggle!(attribute)
toggle(attribute).update_attribute(attribute, self[attribute])
end
# Reloads the attributes of this object from the database.
# The optional options argument is passed to find when reloading so you
# may do e.g. record.reload(:lock => true) to reload the same record with
# an exclusive row lock.
def reload(options = nil)
clear_aggregation_cache
clear_association_cache
@attributes.update(self.class.find(self.id, options).instance_variable_get('@attributes'))
@attributes_cache = {}
self
end
# Returns the value of the attribute identified by attr_name 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).
def [](attr_name)
read_attribute(attr_name)
end
# Updates the attribute identified by attr_name with the specified +value+.
# (Alias for the protected write_attribute method).
def []=(attr_name, value)
write_attribute(attr_name, value)
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). 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.
def attributes=(new_attributes, guard_protected_attributes = true)
return if new_attributes.nil?
attributes = new_attributes.dup
attributes.stringify_keys!
multi_parameter_attributes = []
attributes = remove_attributes_protected_from_mass_assignment(attributes) if guard_protected_attributes
attributes.each do |k, v|
k.include?("(") ? multi_parameter_attributes << [ k, v ] : send(k + "=", v)
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(options = nil)
self.attribute_names.inject({}) do |attrs, name|
attrs[name] = read_attribute(name)
attrs
end
end
# Returns a hash of attributes before typecasting and deserialization.
def attributes_before_type_cast
self.attribute_names.inject({}) do |attrs, name|
attrs[name] = read_attribute_before_type_cast(name)
attrs
end
end
# Format attributes nicely for inspect.
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)
value = read_attribute(attribute)
!value.blank?
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 sorted alphabetically.
def attribute_names
@attributes.keys.sort
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 the +comparison_object+ is the same object, or is of the same type and has the same id.
def ==(comparison_object)
comparison_object.equal?(self) ||
(comparison_object.instance_of?(self.class) &&
comparison_object.id == id &&
!comparison_object.new_record?)
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
# 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?
defined?(@readonly) && @readonly == true
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) || new_record?
"#{name}: #{attribute_for_inspect(name)}"
end
}.compact.join(", ")
"#<#{self.class} #{attributes_as_nice_string}>"
end
private
def create_or_update
raise ReadOnlyRecord if readonly?
result = new_record? ? create : update
result != false
end
# Updates the associated record with values matching those of the instance attributes.
# Returns the number of affected rows.
def update(attribute_names = @attributes.keys)
quoted_attributes = attributes_with_quotes(false, false, attribute_names)
return 0 if quoted_attributes.empty?
connection.update(
"UPDATE #{self.class.quoted_table_name} " +
"SET #{quoted_comma_pair_list(connection, quoted_attributes)} " +
"WHERE #{connection.quote_column_name(self.class.primary_key)} = #{quote_value(id)}",
"#{self.class.name} Update"
)
end
# Creates a record with values matching those of the instance attributes
# and returns its id.
def create
if self.id.nil? && connection.prefetch_primary_key?(self.class.table_name)
self.id = connection.next_sequence_value(self.class.sequence_name)
end
quoted_attributes = attributes_with_quotes
statement = if quoted_attributes.empty?
connection.empty_insert_statement(self.class.table_name)
else
"INSERT INTO #{self.class.quoted_table_name} " +
"(#{quoted_column_names.join(', ')}) " +
"VALUES(#{quoted_attributes.values.join(', ')})"
end
self.id = connection.insert(statement, "#{self.class.name} Create",
self.class.primary_key, self.id, self.class.sequence_name)
@new_record = false
id
end
# Sets the attribute used for single table inheritance to this class name if this is not the ActiveRecord descendent.
# Considering the hierarchy Reply < Message < ActiveRecord, this makes it possible to do Reply.new without having to
# set Reply[Reply.inheritance_column] = "Reply" 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, Inflector.demodulize(self.class.name))
end
end
def convert_number_column_value(value)
case value
when FalseClass; 0
when TrueClass; 1
when ''; nil
else value
end
end
def remove_attributes_protected_from_mass_assignment(attributes)
safe_attributes =
if self.class.accessible_attributes.nil? && self.class.protected_attributes.nil?
attributes.reject { |key, value| attributes_protected_by_default.include?(key.gsub(/\(.+/, "")) }
elsif self.class.protected_attributes.nil?
attributes.reject { |key, value| !self.class.accessible_attributes.include?(key.gsub(/\(.+/, "")) || attributes_protected_by_default.include?(key.gsub(/\(.+/, "")) }
elsif self.class.accessible_attributes.nil?
attributes.reject { |key, value| self.class.protected_attributes.include?(key.gsub(/\(.+/,"")) || attributes_protected_by_default.include?(key.gsub(/\(.+/, "")) }
else
raise "Declare either attr_protected or attr_accessible for #{self.class}, but not both."
end
removed_attributes = attributes.keys - safe_attributes.keys
if removed_attributes.any?
logger.debug "WARNING: Can't mass-assign these protected attributes: #{removed_attributes.join(', ')}"
end
safe_attributes
end
# Removes attributes which have been marked as readonly.
def remove_readonly_attributes(attributes)
unless self.class.readonly_attributes.nil?
attributes.delete_if { |key, value| self.class.readonly_attributes.include?(key.gsub(/\(.+/,"")) }
else
attributes
end
end
# The primary key and inheritance column can never be set by mass-assignment for security reasons.
def attributes_protected_by_default
default = [ self.class.primary_key, self.class.inheritance_column ]
default << 'id' unless self.class.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 SQL statement.
def attributes_with_quotes(include_primary_key = true, include_readonly_attributes = true, attribute_names = @attributes.keys)
quoted = {}
connection = self.class.connection
attribute_names.each do |name|
if column = column_for_attribute(name)
quoted[name] = connection.quote(read_attribute(name), column) unless !include_primary_key && column.primary
end
end
include_readonly_attributes ? quoted : remove_readonly_attributes(quoted)
end
# Quote strings appropriately for SQL statements.
def quote_value(value, column = nil)
self.class.connection.quote(value, column)
end
# Interpolate custom sql string in instance context.
# Optional record argument is meant for custom insert_sql.
def interpolate_sql(sql, record = nil)
instance_eval("%@#{sql.gsub('@', '\@')}@")
end
# Initializes the attributes array with keys matching the columns from the linked table and
# the values matching the corresponding default value of that column, so
# that a new instance, or one populated from a passed-in Hash, still has all the attributes
# that instances loaded from the database would.
def attributes_from_column_definition
self.class.columns.inject({}) do |attributes, column|
attributes[column.name] = column.default unless column.name == self.class.primary_key
attributes
end
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 Time.zone && self.class.time_zone_aware_attributes && !self.class.skip_time_zone_conversion_for_attributes.include?(name.to_sym)
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|
klass = (self.class.reflect_on_aggregation(name.to_sym) || column_for_attribute(name)).klass
if values.empty?
send(name + "=", nil)
else
begin
value = if Time == klass
instantiate_time_object(name, values)
elsif Date == klass
begin
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)
rescue => ex
errors << AttributeAssignmentError.new("error on assignment #{values.inspect} to #{name}", ex, name)
end
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)
unless value.empty?
attributes[attribute_name] <<
[ find_parameter_position(multiparameter_name), type_cast_attribute_value(multiparameter_name, value) ]
end
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 =~ /\([0-9]*([a-z])\)/ ? 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.inject([]) { |list, pair| list << "#{pair.first} = #{pair.last}" }.join(", ")
end
def quoted_column_names(attributes = attributes_with_quotes)
connection = self.class.connection
attributes.keys.collect do |column_name|
connection.quote_column_name(column_name)
end
end
def self.quoted_table_name
self.connection.quote_table_name(self.table_name)
end
def quote_columns(quoter, hash)
hash.inject({}) do |quoted, (name, value)|
quoted[quoter.quote_column_name(name)] = value
quoted
end
end
def quoted_comma_pair_list(quoter, hash)
comma_pair_list(quote_columns(quoter, hash))
end
def object_from_yaml(string)
return string unless string.is_a?(String)
YAML::load(string) rescue string
end
def clone_attributes(reader_method = :read_attribute, attributes = {})
self.attribute_names.inject(attributes) do |attrs, name|
attrs[name] = clone_attribute_value(reader_method, name)
attrs
end
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
end
end