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 files/README.html for more insight.
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 a 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 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 a 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, [
"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 })
All column values are automatically available through basic accessors on the Active Record object, but some times you want to specialize this behavior. This can be done by either by overwriting the default accessors (using the same name as the attribute) 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.
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 <attribute>_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 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, ["user_name = ?", user_name]), you just do Person.find_by_user_name(user_name). And instead of writing Person.find(:all, ["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, ["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. 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")
Use the find_or_initialize_by_ finder if you want to return a new record without saving it first. 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.
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
Active Record allows inheritance by storing the name of the class in a column that by default is called "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: www.martinfowler.com/eaaCatalog/singleTableInheritance.html
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 a 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.
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.
| VALID_FIND_OPTIONS | = | [ :conditions, :include, :joins, :limit, :offset, :order, :select, :readonly, :group, :from, :lock ] |
| set_table_name | -> | table_name= |
| set_primary_key | -> | primary_key= |
| set_inheritance_column | -> | inheritance_column= |
| set_sequence_name | -> | sequence_name= |
| sanitize_sql_for_conditions | -> | sanitize_sql |
| sanitize_sql_hash_for_conditions | -> | sanitize_sql_hash |
| sanitize_sql | -> | sanitize_conditions |
| abstract_class | [RW] | Set this to true if this is an abstract class (see abstract_class?). |
Overwrite the default class equality method to provide support for association proxies.
# File activerecord/lib/active_record/base.rb, line 967 def ===(object) object.is_a?(self) end
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.
# File activerecord/lib/active_record/base.rb, line 983 def abstract_class? abstract_class == true end
If this macro is used, only those attributes named in it will be accessible for mass-assignment, such as new(attributes) and attributes=(attributes). This is the more conservative choice for mass-assignment protection. If you’d rather start from an all-open default and restrict attributes as needed, have a look at attr_protected.
# File activerecord/lib/active_record/base.rb, line 630 def attr_accessible(*attributes) write_inheritable_array("attr_accessible", attributes - (accessible_attributes || [])) 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"
# File activerecord/lib/active_record/base.rb, line 617 def attr_protected(*attributes) write_inheritable_array("attr_protected", attributes - (protected_attributes || [])) end
Attributes listed as readonly can be set for a new record, but will be ignored in database updates afterwards.
# File activerecord/lib/active_record/base.rb, line 640 def attr_readonly(*attributes) write_inheritable_array("attr_readonly", attributes - (readonly_attributes || [])) 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.
# File activerecord/lib/active_record/base.rb, line 974 def base_class class_of_active_record_descendant(self) 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 matches 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.
# File activerecord/lib/active_record/base.rb, line 947 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
Clears the cache which maps classes to connections.
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 84 def clear_active_connections! clear_cache!(@@active_connections) do |name, conn| conn.disconnect! end end
Clears the cache which maps classes
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 91 def clear_reloadable_connections! @@active_connections.each do |name, conn| if conn.requires_reloading? conn.disconnect! @@active_connections.delete(name) end end end
Returns an array of column names as strings.
# File activerecord/lib/active_record/base.rb, line 860 def column_names @column_names ||= columns.map { |column| column.name } end
Returns an array of column objects for the table associated with this class.
# File activerecord/lib/active_record/base.rb, line 846 def columns unless @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.
# File activerecord/lib/active_record/base.rb, line 855 def columns_hash @columns_hash ||= columns.inject({}) { |hash, column| hash[column.name] = column; hash } end
Returns true if a connection that’s accessible to this class have already been opened.
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 260 def self.connected? active_connections[active_connection_name] ? true : false end
Returns the connection currently associated with the class. This can also be used to "borrow" the connection to do database work unrelated to any of the specific Active Records.
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 73 def connection if @active_connection_name && (conn = active_connections[@active_connection_name]) conn else # retrieve_connection sets the cache key. conn = retrieve_connection active_connections[@active_connection_name] = conn end 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.
# File activerecord/lib/active_record/base.rb, line 866 def content_columns @content_columns ||= columns.reject { |c| c.primary || c.name =~ /(_id|_count)$/ || c.name == inheritance_column } 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.
sql: An SQL statement which should return a count query from the database, see the example below
Product.count_by_sql "SELECT COUNT(*) FROM sales s, customers c WHERE s.customer_id = c.id"
# File activerecord/lib/active_record/base.rb, line 541 def count_by_sql(sql) sql = sanitize_conditions(sql) connection.select_value(sql, "#{name} Count").to_i end
Creates an object, instantly saves it as a record (if the validation permits it), and returns it. If the save fails under validations, the unsaved object is still returned.
# File activerecord/lib/active_record/base.rb, line 454 def create(attributes = nil) if attributes.is_a?(Array) attributes.collect { |attr| create(attr) } else object = new(attributes) object.save object end 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.
counter_name The name of the field that should be decremented id The id of the object that should be decremented
# Decrement the post_count column for the record with an id of 5 DiscussionBoard.decrement_counter(:post_count, 5)
# File activerecord/lib/active_record/base.rb, line 597 def decrement_counter(counter_name, id) update_counters(id, counter_name => -1) end
Deletes the record with the given id without instantiating an object first. If an array of ids is provided, all of them are deleted.
# File activerecord/lib/active_record/base.rb, line 489 def delete(id) delete_all([ "#{connection.quote_column_name(primary_key)} IN (?)", id ]) end
Deletes all the records that match the condition without instantiating the objects first (and hence not calling the destroy method). Example:
Post.delete_all "person_id = 5 AND (category = 'Something' OR category = 'Else')"
# File activerecord/lib/active_record/base.rb, line 524 def delete_all(conditions = nil) sql = "DELETE FROM #{table_name} " add_conditions!(sql, conditions, scope(:find)) connection.delete(sql, "#{name} Delete all") end
True if this isn’t a concrete subclass needing a STI type condition.
# File activerecord/lib/active_record/base.rb, line 902 def descends_from_active_record? if superclass.abstract_class? superclass.descends_from_active_record? else superclass == Base || !columns_hash.include?(inheritance_column) end end
Destroys the record with the given id by instantiating the object and calling destroy (all the callbacks are the triggered). If an array of ids is provided, all of them are destroyed.
# File activerecord/lib/active_record/base.rb, line 495 def destroy(id) id.is_a?(Array) ? id.each { |id| destroy(id) } : find(id).destroy end
Destroys the objects for all the records that match the condition by instantiating each object and calling the destroy method. Example:
Person.destroy_all "last_login < '2004-04-04'"
# File activerecord/lib/active_record/base.rb, line 517 def destroy_all(conditions = nil) find(:all, :conditions => conditions).each { |object| object.destroy } end
Establishes the connection to the database. Accepts a hash as input where the :adapter key must be specified with the name of a database adapter (in lower-case) example for regular databases (MySQL, Postgresql, etc):
ActiveRecord::Base.establish_connection(
:adapter => "mysql",
:host => "localhost",
:username => "myuser",
:password => "mypass",
:database => "somedatabase"
)
Example for SQLite database:
ActiveRecord::Base.establish_connection(
:adapter => "sqlite",
:database => "path/to/dbfile"
)
Also accepts keys as strings (for parsing from yaml for example):
ActiveRecord::Base.establish_connection(
"adapter" => "sqlite",
"database" => "path/to/dbfile"
)
The exceptions AdapterNotSpecified, AdapterNotFound and ArgumentError may be returned on an error.
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 191 def self.establish_connection(spec = nil) case spec when nil raise AdapterNotSpecified unless defined? RAILS_ENV establish_connection(RAILS_ENV) when ConnectionSpecification clear_active_connection_name @active_connection_name = name @@defined_connections[name] = spec when Symbol, String if configuration = configurations[spec.to_s] establish_connection(configuration) else raise AdapterNotSpecified, "#{spec} database is not configured" end else spec = spec.symbolize_keys unless spec.key?(:adapter) then raise AdapterNotSpecified, "database configuration does not specify adapter" end tried_gem = false begin require "active_record/connection_adapters/#{spec[:adapter]}_adapter" rescue LoadError raise if tried_gem begin require 'rubygems' gem "activerecord-#{spec[:adapter]}-adapter" rescue LoadError raise "Please install the #{spec[:adapter]} adapter: `gem install activerecord-#{spec[:adapter]}-adapter` (#{$!})" end tried_gem = true retry end adapter_method = "#{spec[:adapter]}_connection" if !respond_to?(adapter_method) raise AdapterNotFound, "database configuration specifies nonexistent #{spec[:adapter]} adapter" end remove_connection establish_connection(ConnectionSpecification.new(spec, adapter_method)) end end
Returns true if the given id represents the primary key of a record in the database, false otherwise. You can also pass a set of SQL conditions. Example:
Person.exists?(5)
Person.exists?('5')
Person.exists?(:name => "David")
Person.exists?(['name LIKE ?', "%#{query}%"])
# File activerecord/lib/active_record/base.rb, line 446 def exists?(id_or_conditions) !find(:first, :select => "#{table_name}.#{primary_key}", :conditions => expand_id_conditions(id_or_conditions)).nil? rescue ActiveRecord::ActiveRecordError false end
Find operates with three different retrieval approaches:
All approaches accept an option hash as their last parameter. The options are:
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 objects 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 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, :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
# File activerecord/lib/active_record/base.rb, line 420 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 :all then find_every(options) else find_from_ids(args, options) end end
Works like find(:all), but requires a complete SQL string. Examples:
Post.find_by_sql "SELECT p.*, c.author FROM posts p, comments c WHERE p.id = c.post_id" Post.find_by_sql ["SELECT * FROM posts WHERE author = ? AND created > ?", author_id, start_date]
# File activerecord/lib/active_record/base.rb, line 435 def find_by_sql(sql) connection.select_all(sanitize_sql(sql), "#{name} Load").collect! { |record| instantiate(record) } 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 a SQL query to find how many posts and comments there are.
counter_name The name of the field that should be incremented id The id of the object that should be incremented
# Increment the post_count column for the record with an id of 5 DiscussionBoard.increment_counter(:post_count, 5)
# File activerecord/lib/active_record/base.rb, line 580 def increment_counter(counter_name, id) update_counters(id, counter_name => 1) end
Defines the column name for use with single table inheritance — can be set in subclasses like so: self.inheritance_column = "type_id"
# File activerecord/lib/active_record/base.rb, line 741 def inheritance_column @inheritance_column ||= "type".freeze end
Returns a string like ‘Post id:integer, title:string, body:text’
# File activerecord/lib/active_record/base.rb, line 911 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
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.
# File activerecord/lib/active_record/base.rb, line 1659 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
Defines the primary key field — can be overridden in subclasses. Overwriting will negate any effect of the primary_key_prefix_type setting, though.
# File activerecord/lib/active_record/base.rb, line 723 def primary_key reset_primary_key end
Returns an array of all the attributes that have been specified as readonly.
# File activerecord/lib/active_record/base.rb, line 645 def readonly_attributes read_inheritable_attribute("attr_readonly") end
Remove the connection for this class. This will close the active connection and the defined connection (if they exist). The result can be used as argument for establish_connection, for easy re-establishing of the connection.
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 268 def self.remove_connection(klass=self) spec = @@defined_connections[klass.name] konn = active_connections[klass.name] @@defined_connections.delete_if { |key, value| value == spec } active_connections.delete_if { |key, value| value == konn } konn.disconnect! if konn spec.config if spec end
# File activerecord/lib/active_record/connection_adapters/mysql_adapter.rb, line 47 def self.require_mysql # Include the MySQL driver if one hasn't already been loaded unless defined? Mysql begin require_library_or_gem 'mysql' rescue LoadError => cannot_require_mysql # Use the bundled Ruby/MySQL driver if no driver is already in place begin ActiveRecord::Base.logger.info( "WARNING: You're using the Ruby-based MySQL library that ships with Rails. This library is not suited for production. " + "Please install the C-based MySQL library instead (gem install mysql)." ) if ActiveRecord::Base.logger require 'active_record/vendor/mysql' rescue LoadError raise cannot_require_mysql end end end # Define Mysql::Result.all_hashes MysqlCompat.define_all_hashes_method! end
Resets all the cached information about columns, which will cause them to be reloaded on the next request.
# File activerecord/lib/active_record/base.rb, line 885 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
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.
attr_name The field name that should be serialized class_name Optional, class name that the object should be equal to
# Serialize a preferences attribute
class User
serialize :preferences
end
# File activerecord/lib/active_record/base.rb, line 664 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.
# File activerecord/lib/active_record/base.rb, line 669 def serialized_attributes read_inheritable_attribute("attr_serialized") or write_inheritable_attribute("attr_serialized", {}) end
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
# File activerecord/lib/active_record/base.rb, line 795 def set_inheritance_column(value = nil, &block) define_attr_method :inheritance_column, value, &block end
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
# File activerecord/lib/active_record/base.rb, line 779 def set_primary_key(value = nil, &block) define_attr_method :primary_key, value, &block end
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
# File activerecord/lib/active_record/base.rb, line 816 def set_sequence_name(value = nil, &block) define_attr_method :sequence_name, value, &block 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
# File activerecord/lib/active_record/base.rb, line 765 def set_table_name(value = nil, &block) define_attr_method :table_name, value, &block end
Silences the logger for the duration of the block.
# File activerecord/lib/active_record/base.rb, line 959 def silence old_logger_level, logger.level = logger.level, Logger::ERROR if logger yield ensure logger.level = old_logger_level if logger end
Indicates whether the table associated with this class exists
# File activerecord/lib/active_record/base.rb, line 830 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
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 from 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 (report a bug if your inflection isn’t covered).
Nested classes are given table names prefixed by the singular form of the parent’s table name. Example:
file class table_name invoice.rb Invoice invoices invoice/lineitem.rb Invoice::Lineitem invoice_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
# File activerecord/lib/active_record/base.rb, line 696 def table_name reset_table_name end
Finds the record from the passed id, instantly saves it with the passed attributes (if the validation permits it), and returns it. If the save fails under validations, the unsaved object is still returned.
The arguments may also be given as arrays in which case the update method is called for each pair of id and attributes and an array of objects is returned.
Example of updating one record:
Person.update(15, {:user_name => 'Samuel', :group => 'expert'})
Example of updating multiple records:
people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy"} }
Person.update(people.keys, people.values)
# File activerecord/lib/active_record/base.rb, line 476 def update(id, attributes) if id.is_a?(Array) idx = -1 id.collect { |id| idx += 1; update(id, attributes[idx]) } else object = find(id) object.update_attributes(attributes) object end end
Updates all records with the SET-part of an SQL update statement in updates and returns an integer with the number of rows updated. A subset of the records can be selected by specifying conditions. Example:
Billing.update_all "category = 'authorized', approved = 1", "author = 'David'"
Optional :order and :limit options may be given as the third parameter, but their behavior is database-specific.
# File activerecord/lib/active_record/base.rb, line 505 def update_all(updates, conditions = nil, options = {}) sql = "UPDATE #{table_name} SET #{sanitize_sql_for_assignment(updates)} " scope = scope(:find) add_conditions!(sql, conditions, scope) add_order!(sql, options[:order], scope) add_limit!(sql, options, scope) connection.update(sql, "#{name} Update") 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:
Post.update_counters 5, :comment_count => -1, :action_count => 1 # UPDATE posts # SET comment_count = comment_count - 1, # action_count = action_count + 1 # WHERE id = 5
# File activerecord/lib/active_record/base.rb, line 557 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
Returns the class descending directly from ActiveRecord in the inheritance hierarchy.
# File activerecord/lib/active_record/base.rb, line 1505 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 class type of the record using the current module as a prefix. So descendents of MyApp::Business::Account would appear as MyApp::Business::AccountSubclass.
# File activerecord/lib/active_record/base.rb, line 1495 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
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'"
# File activerecord/lib/active_record/base.rb, line 1573 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
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'"
# File activerecord/lib/active_record/base.rb, line 1537 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
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'"
# File activerecord/lib/active_record/base.rb, line 1525 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
Sanitizes a hash of attribute/value pairs into SQL conditions for a SET clause.
{ :status => nil, :group_id => 1 }
# => "status = NULL , group_id = 1"
# File activerecord/lib/active_record/base.rb, line 1564 def sanitize_sql_hash_for_assignment(attrs) conditions = attrs.map do |attr, value| "#{connection.quote_column_name(attr)} = #{quote_bound_value(value)}" end.join(', ') 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"
# File activerecord/lib/active_record/base.rb, line 1552 def sanitize_sql_hash_for_conditions(attrs) conditions = attrs.map do |attr, value| "#{table_name}.#{connection.quote_column_name(attr)} #{attribute_condition(value)}" end.join(' AND ') replace_bind_variables(conditions, expand_range_bind_variables(attrs.values)) end
Works like with_scope, but discards any nested properties.
# File activerecord/lib/active_record/base.rb, line 1450 def with_exclusive_scope(method_scoping = {}, &block) with_scope(method_scoping, :overwrite, &block) end
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 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
# File activerecord/lib/active_record/base.rb, line 1398 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([ :conditions, :joins, :select, :include, :from, :offset, :limit, :order, :group, :readonly, :lock ]) 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] = [params[key], hash[method][key]].collect{ |sql| "( %s )" % sanitize_sql(sql) }.join(" AND ") 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
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.
# File activerecord/lib/active_record/base.rb, line 1197 def add_conditions!(sql, conditions, scope = :auto) scope = scope(:find) if :auto == scope segments = [] segments << sanitize_sql(scope[:conditions]) if scope && !scope[:conditions].blank? segments << sanitize_sql(conditions) unless conditions.blank? segments << type_condition unless descends_from_active_record? segments.compact! sql << "WHERE (#{segments.join(") AND (")}) " unless segments.all?(&:blank?) end
# File activerecord/lib/active_record/base.rb, line 1157 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.
# File activerecord/lib/active_record/base.rb, line 1189 def add_joins!(sql, options, scope = :auto) scope = scope(:find) if :auto == scope join = (scope && scope[:joins]) || options[:joins] sql << " #{join} " if join end
The optional scope argument is for the current :find scope.
# File activerecord/lib/active_record/base.rb, line 1169 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.
# File activerecord/lib/active_record/base.rb, line 1182 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
# File activerecord/lib/active_record/base.rb, line 1146 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
# File activerecord/lib/active_record/base.rb, line 1304 def all_attributes_exists?(attribute_names) attribute_names.all? { |name| column_methods_hash.include?(name.to_sym) } end
# File activerecord/lib/active_record/base.rb, line 1308 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
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 144 def clear_all_cached_connections! if @@allow_concurrency @@active_connections.each_value do |connection_hash_for_thread| connection_hash_for_thread.each_value {|conn| conn.disconnect! } connection_hash_for_thread.clear end else @@active_connections.each_value {|conn| conn.disconnect! } end @@active_connections.clear end
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 114 def clear_cache!(cache, thread_id = nil, &block) if cache if @@allow_concurrency thread_id ||= Thread.current.object_id thread_cache, cache = cache, cache[thread_id] return unless cache end cache.each(&block) if block_given? cache.clear end ensure if thread_cache && @@allow_concurrency thread_cache.delete(thread_id) end end
# File activerecord/lib/active_record/base.rb, line 1298 def construct_attributes_from_arguments(attribute_names, arguments) attributes = {} attribute_names.each_with_index { |name, idx| attributes[name] = arguments[idx] } attributes end
# File activerecord/lib/active_record/base.rb, line 1113 def construct_finder_sql(options) scope = scope(:find) sql = "SELECT #{(scope && scope[:select]) || options[:select] || (options[:joins] && table_name + '.*') || '*'} " sql << "FROM #{(scope && scope[:from]) || options[:from] || 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
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
# File activerecord/lib/active_record/base.rb, line 1344 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
# File activerecord/lib/active_record/base.rb, line 1286 def determine_finder(match) match.captures.first == 'all_by' ? :find_every : :find_initial end
# File activerecord/lib/active_record/base.rb, line 1290 def determine_instantiator(match) match.captures.first == 'initialize' ? :new : :create end
Interpret Array and Hash as conditions and anything else as an id.
# File activerecord/lib/active_record/base.rb, line 1318 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
# File activerecord/lib/active_record/base.rb, line 1294 def extract_attribute_names_from_match(match) match.captures.last.split('_and_') end
# File activerecord/lib/active_record/base.rb, line 993 def find_every(options) records = scoped?(:find, :include) || options[:include] ? find_with_associations(options) : find_by_sql(construct_finder_sql(options)) records.each { |record| record.readonly! } if options[:readonly] records end
# File activerecord/lib/active_record/base.rb, line 1003 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
# File activerecord/lib/active_record/base.rb, line 988 def find_initial(options) options.update(:limit => 1) unless options[:include] find_every(options).first end
# File activerecord/lib/active_record/base.rb, line 1020 def find_one(id, options) conditions = " AND (#{sanitize_sql(options[:conditions])})" if options[:conditions] options.update :conditions => "#{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
# File activerecord/lib/active_record/base.rb, line 1034 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 => "#{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.
# File activerecord/lib/active_record/base.rb, line 1064 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
Merges includes so that the result is a valid include
# File activerecord/lib/active_record/base.rb, line 1130 def merge_includes(first, second) (safe_to_array(first) + safe_to_array(second)).uniq 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), but using find_all_by_amount(50) that are 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.
# File activerecord/lib/active_record/base.rb, line 1235 def method_missing(method_id, *arguments) if match = /^find_(all_by|by)_([_a-zA-Z]\w*)$/.match(method_id.to_s) finder = determine_finder(match) attribute_names = extract_attribute_names_from_match(match) super unless all_attributes_exists?(attribute_names) self.class_eval %{ def self.#{method_id}(*args) options = args.last.is_a?(Hash) ? args.pop : {} attributes = construct_attributes_from_arguments([:#{attribute_names.join(',:')}], args) finder_options = { :conditions => attributes } validate_find_options(options) set_readonly_option!(options) if options[:conditions] with_scope(:find => finder_options) do ActiveSupport::Deprecation.silence { send(:#{finder}, options) } end else ActiveSupport::Deprecation.silence { send(:#{finder}, options.merge(finder_options)) } end end } send(method_id, *arguments) elsif match = /^find_or_(initialize|create)_by_([_a-zA-Z]\w*)$/.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) if args[0].is_a?(Hash) 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) find_initial(options) || send(:#{instantiator}, attributes) end } send(method_id, *arguments) else super end end
# File activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb, line 28 def parse_sqlite_config!(config) config[:database] ||= config[:dbfile] # Require database. unless config[:database] raise ArgumentError, "No database file specified. Missing argument: database" end # Allow database path relative to RAILS_ROOT, but only if # the database path is not the special path that tells # Sqlite build a database only in memory. if Object.const_defined?(:RAILS_ROOT) && ':memory:' != config[:database] config[:database] = File.expand_path(config[:database], RAILS_ROOT) end end
Remove stale threads from the cache.
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 132 def remove_stale_cached_threads!(cache, &block) stale = Set.new(cache.keys) Thread.list.each do |thread| stale.delete(thread.object_id) if thread.alive? end stale.each do |thread_id| clear_cache!(cache, thread_id, &block) end end
Object#to_a is deprecated, though it does have the desired behavior
# File activerecord/lib/active_record/base.rb, line 1135 def safe_to_array(o) case o when NilClass [] when Array o else [o] end end
# File activerecord/lib/active_record/base.rb, line 1207 def type_condition quoted_inheritance_column = connection.quote_column_name(inheritance_column) type_condition = subclasses.inject("#{table_name}.#{quoted_inheritance_column} = '#{name.demodulize}' ") do |condition, subclass| condition << "OR #{table_name}.#{quoted_inheritance_column} = '#{subclass.name.demodulize}' " end " (#{type_condition}) " end
Nest the type name in the same module as this class. Bar is "MyApp::Business::Bar" relative to MyApp::Business::Foo
# File activerecord/lib/active_record/base.rb, line 1109 def type_name_with_module(type_name) (/^::/ =~ type_name) ? type_name : "#{parent.name}::#{type_name}" end
Guesses the table name, but does not decorate it with prefix and suffix information.
# File activerecord/lib/active_record/base.rb, line 1217 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
Returns true if the comparison_object is the same object, or is of the same type and has the same id.
# File activerecord/lib/active_record/base.rb, line 1908 def ==(comparison_object) comparison_object.equal?(self) || (comparison_object.instance_of?(self.class) && comparison_object.id == id && !comparison_object.new_record?) 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).
# File activerecord/lib/active_record/base.rb, line 1817 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).
# File activerecord/lib/active_record/base.rb, line 1823 def []=(attr_name, value) write_attribute(attr_name, value) end
Format attributes nicely for inspect.
# File activerecord/lib/active_record/base.rb, line 1873 def attribute_for_inspect(attr_name) value = read_attribute(attr_name) if value.is_a?(String) && value.length > 50 %("#{value[0..50]}...") elsif value.is_a?(Date) || value.is_a?(Time) %("#{value.to_s(:db)}") else value.inspect end end
Returns an array of names for the attributes available on this object sorted alphabetically.
# File activerecord/lib/active_record/base.rb, line 1898 def attribute_names @attributes.keys.sort 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).
# File activerecord/lib/active_record/base.rb, line 1887 def attribute_present?(attribute) value = read_attribute(attribute) !value.blank? end
Returns a hash of all the attributes with their names as keys and clones of their objects as values.
# File activerecord/lib/active_record/base.rb, line 1847 def attributes(options = nil) attributes = clone_attributes :read_attribute if options.nil? attributes else if except = options[:except] except = Array(except).collect { |attribute| attribute.to_s } except.each { |attribute_name| attributes.delete(attribute_name) } attributes elsif only = options[:only] only = Array(only).collect { |attribute| attribute.to_s } attributes.delete_if { |key, value| !only.include?(key) } attributes else raise ArgumentError, "Options does not specify :except or :only (#{options.keys.inspect})" end end 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 in with the attr_accessible macro. Then all the attributes not included in that won’t be allowed to be mass-assigned.
# File activerecord/lib/active_record/base.rb, line 1832 def attributes=(new_attributes) return if new_attributes.nil? attributes = new_attributes.dup attributes.stringify_keys! multi_parameter_attributes = [] remove_attributes_protected_from_mass_assignment(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 cloned attributes before typecasting and deserialization.
# File activerecord/lib/active_record/base.rb, line 1868 def attributes_before_type_cast clone_attributes :read_attribute_before_type_cast 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.
# File activerecord/lib/active_record/base.rb, line 1738 def clone attrs = self.attributes_before_type_cast attrs.delete(self.class.primary_key) self.class.new do |record| record.send :instance_variable_set, '@attributes', attrs end end
Returns the column object for the named attribute.
# File activerecord/lib/active_record/base.rb, line 1903 def column_for_attribute(name) self.class.columns_hash[name.to_s] end
Returns the connection currently associated with the class. This can also be used to "borrow" the connection to do database work that isn’t easily done without going straight to SQL.
# File activerecord/lib/active_record/connection_adapters/abstract/connection_specification.rb, line 160 def connection self.class.connection end
Initializes the attribute to zero if nil and subtracts one. Only makes sense for number-based attributes. Returns self.
# File activerecord/lib/active_record/base.rb, line 1780 def decrement(attribute) self[attribute] ||= 0 self[attribute] -= 1 self end
Decrements the attribute and saves the record.
# File activerecord/lib/active_record/base.rb, line 1787 def decrement!(attribute) decrement(attribute).update_attribute(attribute, self[attribute]) 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).
# File activerecord/lib/active_record/base.rb, line 1721 def destroy unless new_record? connection.delete "DELETE FROM \#{self.class.table_name}\nWHERE \#{connection.quote_column_name(self.class.primary_key)} = \#{quoted_id}\n", "#{self.class.name} Destroy" end freeze end
Delegates to ==
# File activerecord/lib/active_record/base.rb, line 1916 def eql?(comparison_object) self == (comparison_object) end
Just freeze the attributes hash, such that associations are still accessible even on destroyed records.
# File activerecord/lib/active_record/base.rb, line 1927 def freeze @attributes.freeze; self end
Returns true if the given attribute is in the attributes hash
# File activerecord/lib/active_record/base.rb, line 1893 def has_attribute?(attr_name) @attributes.has_key?(attr_name.to_s) end
Delegates to id in order to allow two records of the same type and id to work with something like:
[ Person.find(1), Person.find(2), Person.find(3) ] & [ Person.find(1), Person.find(4) ] # => [ Person.find(1) ]
# File activerecord/lib/active_record/base.rb, line 1922 def hash id.hash 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.
# File activerecord/lib/active_record/base.rb, line 1673 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
Sets the primary ID.
# File activerecord/lib/active_record/base.rb, line 1698 def id=(value) write_attribute(self.class.primary_key, value) end
Initializes the attribute to zero if nil and adds one. Only makes sense for number-based attributes. Returns self.
# File activerecord/lib/active_record/base.rb, line 1768 def increment(attribute) self[attribute] ||= 0 self[attribute] += 1 self end
Increments the attribute and saves the record.
# File activerecord/lib/active_record/base.rb, line 1775 def increment!(attribute) increment(attribute).update_attribute(attribute, self[attribute]) end
Nice pretty inspect.
# File activerecord/lib/active_record/base.rb, line 1945 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
Returns true if this object hasn’t been saved yet — that is, a record for the object doesn’t exist yet.
# File activerecord/lib/active_record/base.rb, line 1703 def new_record? @new_record end
Records loaded through joins with piggy-back attributes will be marked as read only as they cannot be saved and return true to this query.
# File activerecord/lib/active_record/base.rb, line 1936 def readonly? @readonly == true 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.
# File activerecord/lib/active_record/base.rb, line 1806 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
# File activerecord/lib/active_record/base.rb, line 1709 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
# File activerecord/lib/active_record/base.rb, line 1715 def save! create_or_update || raise(RecordNotSaved) end
Enables Active Record objects to be used as URL parameters in Action Pack automatically.
# File activerecord/lib/active_record/base.rb, line 1684 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
Turns an attribute that’s currently true into false and vice versa. Returns self.
# File activerecord/lib/active_record/base.rb, line 1792 def toggle(attribute) self[attribute] = !send("#{attribute}?") self end
Toggles the attribute and saves the record.
# File activerecord/lib/active_record/base.rb, line 1798 def toggle!(attribute) toggle(attribute).update_attribute(attribute, self[attribute]) 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.
# File activerecord/lib/active_record/base.rb, line 1749 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.
# File activerecord/lib/active_record/base.rb, line 1756 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.
# File activerecord/lib/active_record/base.rb, line 1762 def update_attributes!(attributes) self.attributes = attributes save! 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 is empty, the attribute will be set to nil.
# File activerecord/lib/active_record/base.rb, line 2078 def assign_multiparameter_attributes(pairs) execute_callstack_for_multiparameter_attributes( extract_callstack_for_multiparameter_attributes(pairs) ) 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.
# File activerecord/lib/active_record/base.rb, line 2065 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
The primary key and inheritance column can never be set by mass-assignment for security reasons.
# File activerecord/lib/active_record/base.rb, line 2032 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 copy of the attributes hash where all the values have been safely quoted for use in an SQL statement.
# File activerecord/lib/active_record/base.rb, line 2040 def attributes_with_quotes(include_primary_key = true, include_readonly_attributes = true) quoted = attributes.inject({}) do |quoted, (name, value)| if column = column_for_attribute(name) quoted[name] = quote_value(value, column) unless !include_primary_key && column.primary end quoted end include_readonly_attributes ? quoted : remove_readonly_attributes(quoted) end
# File activerecord/lib/active_record/base.rb, line 2163 def clone_attribute_value(reader_method, attribute_name) value = send(reader_method, attribute_name) case value when nil, Fixnum, true, false value else value.clone end rescue TypeError, NoMethodError value end
# File activerecord/lib/active_record/base.rb, line 2156 def clone_attributes(reader_method = :read_attribute, attributes = {}) self.attribute_names.inject(attributes) do |attributes, name| attributes[name] = clone_attribute_value(reader_method, name) attributes end end
Returns a comma-separated pair list, like "key1 = val1, key2 = val2".
# File activerecord/lib/active_record/base.rb, line 2130 def comma_pair_list(hash) hash.inject([]) { |list, pair| list << "#{pair.first} = #{pair.last}" }.join(", ") end
# File activerecord/lib/active_record/base.rb, line 2001 def convert_number_column_value(value) case value when FalseClass; 0 when TrueClass; 1 when ''; nil else value end end
Creates a record with values matching those of the instance attributes and returns its id.
# File activerecord/lib/active_record/base.rb, line 1974 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 self.id = connection.insert( "INSERT INTO #{self.class.table_name} " + "(#{quoted_column_names.join(', ')}) " + "VALUES(#{attributes_with_quotes.values.join(', ')})", "#{self.class.name} Create", self.class.primary_key, self.id, self.class.sequence_name ) @new_record = false id end
# File activerecord/lib/active_record/base.rb, line 1955 def create_or_update raise ReadOnlyRecord if readonly? result = new_record? ? create : update result != false 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" yourself. No such attribute would be set for objects of the Message class in that example.
# File activerecord/lib/active_record/base.rb, line 1995 def ensure_proper_type unless self.class.descends_from_active_record? write_attribute(self.class.inheritance_column, Inflector.demodulize(self.class.name)) end end
Includes an ugly hack for Time.local instead of Time.new because the latter is reserved by Time itself.
# File activerecord/lib/active_record/base.rb, line 2085 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 send(name + "=", Time == klass ? (@@default_timezone == :utc ? klass.utc(*values) : klass.local(*values)) : klass.new(*values)) 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
# File activerecord/lib/active_record/base.rb, line 2104 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
# File activerecord/lib/active_record/base.rb, line 2125 def find_parameter_position(multiparameter_name) multiparameter_name.scan(/\(([0-9]*).*\)/).first.first end
Interpolate custom sql string in instance context. Optional record argument is meant for custom insert_sql.
# File activerecord/lib/active_record/base.rb, line 2057 def interpolate_sql(sql, record = nil) instance_eval("%@#{sql.gsub('@', '\@')}@") end
# File activerecord/lib/active_record/base.rb, line 2151 def object_from_yaml(string) return string unless string.is_a?(String) YAML::load(string) rescue string end
# File activerecord/lib/active_record/base.rb, line 2140 def quote_columns(quoter, hash) hash.inject({}) do |quoted, (name, value)| quoted[quoter.quote_column_name(name)] = value quoted end end
Quote strings appropriately for SQL statements.
# File activerecord/lib/active_record/base.rb, line 2051 def quote_value(value, column = nil) self.class.connection.quote(value, column) end
# File activerecord/lib/active_record/base.rb, line 2134 def quoted_column_names(attributes = attributes_with_quotes) attributes.keys.collect do |column_name| self.class.connection.quote_column_name(column_name) end end
# File activerecord/lib/active_record/base.rb, line 2147 def quoted_comma_pair_list(quoter, hash) comma_pair_list(quote_columns(quoter, hash)) end
# File activerecord/lib/active_record/base.rb, line 2010 def remove_attributes_protected_from_mass_assignment(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(/\(.+/, "").intern) || attributes_protected_by_default.include?(key.gsub(/\(.+/, "")) } elsif self.class.accessible_attributes.nil? attributes.reject { |key, value| self.class.protected_attributes.include?(key.gsub(/\(.+/,"").intern) || attributes_protected_by_default.include?(key.gsub(/\(.+/, "")) } else raise "Declare either attr_protected or attr_accessible for #{self.class}, but not both." end end
Removes attributes which have been marked as readonly.
# File activerecord/lib/active_record/base.rb, line 2023 def remove_readonly_attributes(attributes) unless self.class.readonly_attributes.nil? attributes.delete_if { |key, value| self.class.readonly_attributes.include?(key.gsub(/\(.+/,"").intern) } else attributes end end
# File activerecord/lib/active_record/base.rb, line 2121 def type_cast_attribute_value(multiparameter_name, value) multiparameter_name =~ /\([0-9]*([a-z])\)/ ? value.send("to_" + $1) : value end
Updates the associated record with values matching those of the instance attributes. Returns the number of affected rows.
# File activerecord/lib/active_record/base.rb, line 1963 def update connection.update( "UPDATE #{self.class.table_name} " + "SET #{quoted_comma_pair_list(connection, attributes_with_quotes(false, false))} " + "WHERE #{connection.quote_column_name(self.class.primary_key)} = #{quote_value(id)}", "#{self.class.name} Update" ) end