/usr/lib/ruby/vendor_ruby/active_record/scoping/named.rb is in ruby-activerecord-3.2 3.2.16-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 | require 'active_support/core_ext/array'
require 'active_support/core_ext/hash/except'
require 'active_support/core_ext/kernel/singleton_class'
require 'active_support/core_ext/object/blank'
require 'active_support/core_ext/class/attribute'
module ActiveRecord
# = Active Record Named \Scopes
module Scoping
module Named
extend ActiveSupport::Concern
module ClassMethods
# Returns an anonymous \scope.
#
# posts = Post.scoped
# posts.size # Fires "select count(*) from posts" and returns the count
# posts.each {|p| puts p.name } # Fires "select * from posts" and loads post objects
#
# fruits = Fruit.scoped
# fruits = fruits.where(:color => 'red') if options[:red_only]
# fruits = fruits.limit(10) if limited?
#
# Anonymous \scopes tend to be useful when procedurally generating complex
# queries, where passing intermediate values (\scopes) around as first-class
# objects is convenient.
#
# You can define a \scope that applies to all finders using
# ActiveRecord::Base.default_scope.
def scoped(options = nil)
if options
scoped.apply_finder_options(options)
else
if current_scope
current_scope.clone
else
scope = relation
scope.default_scoped = true
scope
end
end
end
##
# Collects attributes from scopes that should be applied when creating
# an AR instance for the particular class this is called on.
def scope_attributes # :nodoc:
if current_scope
current_scope.scope_for_create
else
scope = relation
scope.default_scoped = true
scope.scope_for_create
end
end
##
# Are there default attributes associated with this scope?
def scope_attributes? # :nodoc:
current_scope || default_scopes.any?
end
# Adds a class method for retrieving and querying objects. A \scope represents a narrowing of a database query,
# such as <tt>where(:color => :red).select('shirts.*').includes(:washing_instructions)</tt>.
#
# class Shirt < ActiveRecord::Base
# scope :red, where(:color => 'red')
# scope :dry_clean_only, joins(:washing_instructions).where('washing_instructions.dry_clean_only = ?', true)
# end
#
# The above calls to <tt>scope</tt> define class methods Shirt.red and Shirt.dry_clean_only. Shirt.red,
# in effect, represents the query <tt>Shirt.where(:color => 'red')</tt>.
#
# Note that this is simply 'syntactic sugar' for defining an actual class method:
#
# class Shirt < ActiveRecord::Base
# def self.red
# where(:color => 'red')
# end
# end
#
# Unlike <tt>Shirt.find(...)</tt>, however, the object returned by Shirt.red is not an Array; it
# resembles the association object constructed by a <tt>has_many</tt> declaration. For instance,
# you can invoke <tt>Shirt.red.first</tt>, <tt>Shirt.red.count</tt>, <tt>Shirt.red.where(:size => 'small')</tt>.
# Also, just as with the association objects, named \scopes act like an Array, implementing Enumerable;
# <tt>Shirt.red.each(&block)</tt>, <tt>Shirt.red.first</tt>, and <tt>Shirt.red.inject(memo, &block)</tt>
# all behave as if Shirt.red really was an Array.
#
# These named \scopes are composable. For instance, <tt>Shirt.red.dry_clean_only</tt> will produce
# all shirts that are both red and dry clean only.
# Nested finds and calculations also work with these compositions: <tt>Shirt.red.dry_clean_only.count</tt>
# returns the number of garments for which these criteria obtain. Similarly with
# <tt>Shirt.red.dry_clean_only.average(:thread_count)</tt>.
#
# All \scopes are available as class methods on the ActiveRecord::Base descendant upon which
# the \scopes were defined. But they are also available to <tt>has_many</tt> associations. If,
#
# class Person < ActiveRecord::Base
# has_many :shirts
# end
#
# then <tt>elton.shirts.red.dry_clean_only</tt> will return all of Elton's red, dry clean
# only shirts.
#
# Named \scopes can also be procedural:
#
# class Shirt < ActiveRecord::Base
# scope :colored, lambda { |color| where(:color => color) }
# end
#
# In this example, <tt>Shirt.colored('puce')</tt> finds all puce shirts.
#
# On Ruby 1.9 you can use the 'stabby lambda' syntax:
#
# scope :colored, ->(color) { where(:color => color) }
#
# Note that scopes defined with \scope will be evaluated when they are defined, rather than
# when they are used. For example, the following would be incorrect:
#
# class Post < ActiveRecord::Base
# scope :recent, where('published_at >= ?', Time.current - 1.week)
# end
#
# The example above would be 'frozen' to the <tt>Time.current</tt> value when the <tt>Post</tt>
# class was defined, and so the resultant SQL query would always be the same. The correct
# way to do this would be via a lambda, which will re-evaluate the scope each time
# it is called:
#
# class Post < ActiveRecord::Base
# scope :recent, lambda { where('published_at >= ?', Time.current - 1.week) }
# end
#
# Named \scopes can also have extensions, just as with <tt>has_many</tt> declarations:
#
# class Shirt < ActiveRecord::Base
# scope :red, where(:color => 'red') do
# def dom_id
# 'red_shirts'
# end
# end
# end
#
# Scopes can also be used while creating/building a record.
#
# class Article < ActiveRecord::Base
# scope :published, where(:published => true)
# end
#
# Article.published.new.published # => true
# Article.published.create.published # => true
#
# Class methods on your model are automatically available
# on scopes. Assuming the following setup:
#
# class Article < ActiveRecord::Base
# scope :published, where(:published => true)
# scope :featured, where(:featured => true)
#
# def self.latest_article
# order('published_at desc').first
# end
#
# def self.titles
# pluck(:title)
# end
# end
#
# We are able to call the methods like this:
#
# Article.published.featured.latest_article
# Article.featured.titles
def scope(name, scope_options = {})
name = name.to_sym
valid_scope_name?(name)
extension = Module.new(&Proc.new) if block_given?
scope_proc = lambda do |*args|
options = scope_options.respond_to?(:call) ? unscoped { scope_options.call(*args) } : scope_options
options = scoped.apply_finder_options(options) if options.is_a?(Hash)
relation = scoped.merge(options)
extension ? relation.extending(extension) : relation
end
singleton_class.send(:redefine_method, name, &scope_proc)
end
protected
def valid_scope_name?(name)
if logger && respond_to?(name, true)
logger.warn "Creating scope :#{name}. " \
"Overwriting existing method #{self.name}.#{name}."
end
end
end
end
end
end
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