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require "active_record/relation/from_clause"
require "active_record/relation/query_attribute"
require "active_record/relation/where_clause"
require "active_record/relation/where_clause_factory"
require 'active_model/forbidden_attributes_protection'
require 'active_support/core_ext/string/filters'
module ActiveRecord
module QueryMethods
extend ActiveSupport::Concern
include ActiveModel::ForbiddenAttributesProtection
# WhereChain objects act as placeholder for queries in which #where does not have any parameter.
# In this case, #where must be chained with #not to return a new relation.
class WhereChain
def initialize(scope)
@scope = scope
end
# Returns a new relation expressing WHERE + NOT condition according to
# the conditions in the arguments.
#
# +not+ accepts conditions as a string, array, or hash. See #where for
# more details on each format.
#
# User.where.not("name = 'Jon'")
# # SELECT * FROM users WHERE NOT (name = 'Jon')
#
# User.where.not(["name = ?", "Jon"])
# # SELECT * FROM users WHERE NOT (name = 'Jon')
#
# User.where.not(name: "Jon")
# # SELECT * FROM users WHERE name != 'Jon'
#
# User.where.not(name: nil)
# # SELECT * FROM users WHERE name IS NOT NULL
#
# User.where.not(name: %w(Ko1 Nobu))
# # SELECT * FROM users WHERE name NOT IN ('Ko1', 'Nobu')
#
# User.where.not(name: "Jon", role: "admin")
# # SELECT * FROM users WHERE name != 'Jon' AND role != 'admin'
def not(opts, *rest)
where_clause = @scope.send(:where_clause_factory).build(opts, rest)
@scope.references!(PredicateBuilder.references(opts)) if Hash === opts
@scope.where_clause += where_clause.invert
@scope
end
end
Relation::MULTI_VALUE_METHODS.each do |name|
class_eval <<-CODE, __FILE__, __LINE__ + 1
def #{name}_values # def select_values
@values[:#{name}] || [] # @values[:select] || []
end # end
#
def #{name}_values=(values) # def select_values=(values)
assert_mutability! # assert_mutability!
@values[:#{name}] = values # @values[:select] = values
end # end
CODE
end
(Relation::SINGLE_VALUE_METHODS - [:create_with]).each do |name|
class_eval <<-CODE, __FILE__, __LINE__ + 1
def #{name}_value # def readonly_value
@values[:#{name}] # @values[:readonly]
end # end
CODE
end
Relation::SINGLE_VALUE_METHODS.each do |name|
class_eval <<-CODE, __FILE__, __LINE__ + 1
def #{name}_value=(value) # def readonly_value=(value)
assert_mutability! # assert_mutability!
@values[:#{name}] = value # @values[:readonly] = value
end # end
CODE
end
Relation::CLAUSE_METHODS.each do |name|
class_eval <<-CODE, __FILE__, __LINE__ + 1
def #{name}_clause # def where_clause
@values[:#{name}] || new_#{name}_clause # @values[:where] || new_where_clause
end # end
#
def #{name}_clause=(value) # def where_clause=(value)
assert_mutability! # assert_mutability!
@values[:#{name}] = value # @values[:where] = value
end # end
CODE
end
def bound_attributes
from_clause.binds + arel.bind_values + where_clause.binds + having_clause.binds
end
def create_with_value # :nodoc:
@values[:create_with] || {}
end
alias extensions extending_values
# Specify relationships to be included in the result set. For
# example:
#
# users = User.includes(:address)
# users.each do |user|
# user.address.city
# end
#
# allows you to access the +address+ attribute of the +User+ model without
# firing an additional query. This will often result in a
# performance improvement over a simple +join+.
#
# You can also specify multiple relationships, like this:
#
# users = User.includes(:address, :friends)
#
# Loading nested relationships is possible using a Hash:
#
# users = User.includes(:address, friends: [:address, :followers])
#
# === conditions
#
# If you want to add conditions to your included models you'll have
# to explicitly reference them. For example:
#
# User.includes(:posts).where('posts.name = ?', 'example')
#
# Will throw an error, but this will work:
#
# User.includes(:posts).where('posts.name = ?', 'example').references(:posts)
#
# Note that +includes+ works with association names while +references+ needs
# the actual table name.
def includes(*args)
check_if_method_has_arguments!(:includes, args)
spawn.includes!(*args)
end
def includes!(*args) # :nodoc:
args.reject!(&:blank?)
args.flatten!
self.includes_values |= args
self
end
# Forces eager loading by performing a LEFT OUTER JOIN on +args+:
#
# User.eager_load(:posts)
# => SELECT "users"."id" AS t0_r0, "users"."name" AS t0_r1, ...
# FROM "users" LEFT OUTER JOIN "posts" ON "posts"."user_id" =
# "users"."id"
def eager_load(*args)
check_if_method_has_arguments!(:eager_load, args)
spawn.eager_load!(*args)
end
def eager_load!(*args) # :nodoc:
self.eager_load_values += args
self
end
# Allows preloading of +args+, in the same way that +includes+ does:
#
# User.preload(:posts)
# => SELECT "posts".* FROM "posts" WHERE "posts"."user_id" IN (1, 2, 3)
def preload(*args)
check_if_method_has_arguments!(:preload, args)
spawn.preload!(*args)
end
def preload!(*args) # :nodoc:
self.preload_values += args
self
end
# Use to indicate that the given +table_names+ are referenced by an SQL string,
# and should therefore be JOINed in any query rather than loaded separately.
# This method only works in conjunction with +includes+.
# See #includes for more details.
#
# User.includes(:posts).where("posts.name = 'foo'")
# # => Doesn't JOIN the posts table, resulting in an error.
#
# User.includes(:posts).where("posts.name = 'foo'").references(:posts)
# # => Query now knows the string references posts, so adds a JOIN
def references(*table_names)
check_if_method_has_arguments!(:references, table_names)
spawn.references!(*table_names)
end
def references!(*table_names) # :nodoc:
table_names.flatten!
table_names.map!(&:to_s)
self.references_values |= table_names
self
end
# Works in two unique ways.
#
# First: takes a block so it can be used just like Array#select.
#
# Model.all.select { |m| m.field == value }
#
# This will build an array of objects from the database for the scope,
# converting them into an array and iterating through them using Array#select.
#
# Second: Modifies the SELECT statement for the query so that only certain
# fields are retrieved:
#
# Model.select(:field)
# # => [#<Model id: nil, field: "value">]
#
# Although in the above example it looks as though this method returns an
# array, it actually returns a relation object and can have other query
# methods appended to it, such as the other methods in ActiveRecord::QueryMethods.
#
# The argument to the method can also be an array of fields.
#
# Model.select(:field, :other_field, :and_one_more)
# # => [#<Model id: nil, field: "value", other_field: "value", and_one_more: "value">]
#
# You can also use one or more strings, which will be used unchanged as SELECT fields.
#
# Model.select('field AS field_one', 'other_field AS field_two')
# # => [#<Model id: nil, field: "value", other_field: "value">]
#
# If an alias was specified, it will be accessible from the resulting objects:
#
# Model.select('field AS field_one').first.field_one
# # => "value"
#
# Accessing attributes of an object that do not have fields retrieved by a select
# except +id+ will throw <tt>ActiveModel::MissingAttributeError</tt>:
#
# Model.select(:field).first.other_field
# # => ActiveModel::MissingAttributeError: missing attribute: other_field
def select(*fields)
return super if block_given?
raise ArgumentError, 'Call this with at least one field' if fields.empty?
spawn._select!(*fields)
end
def _select!(*fields) # :nodoc:
fields.flatten!
fields.map! do |field|
klass.attribute_alias?(field) ? klass.attribute_alias(field) : field
end
self.select_values += fields
self
end
# Allows to specify a group attribute:
#
# User.group(:name)
# => SELECT "users".* FROM "users" GROUP BY name
#
# Returns an array with distinct records based on the +group+ attribute:
#
# User.select([:id, :name])
# => [#<User id: 1, name: "Oscar">, #<User id: 2, name: "Oscar">, #<User id: 3, name: "Foo">
#
# User.group(:name)
# => [#<User id: 3, name: "Foo", ...>, #<User id: 2, name: "Oscar", ...>]
#
# User.group('name AS grouped_name, age')
# => [#<User id: 3, name: "Foo", age: 21, ...>, #<User id: 2, name: "Oscar", age: 21, ...>, #<User id: 5, name: "Foo", age: 23, ...>]
#
# Passing in an array of attributes to group by is also supported.
# User.select([:id, :first_name]).group(:id, :first_name).first(3)
# => [#<User id: 1, first_name: "Bill">, #<User id: 2, first_name: "Earl">, #<User id: 3, first_name: "Beto">]
def group(*args)
check_if_method_has_arguments!(:group, args)
spawn.group!(*args)
end
def group!(*args) # :nodoc:
args.flatten!
self.group_values += args
self
end
# Allows to specify an order attribute:
#
# User.order(:name)
# => SELECT "users".* FROM "users" ORDER BY "users"."name" ASC
#
# User.order(email: :desc)
# => SELECT "users".* FROM "users" ORDER BY "users"."email" DESC
#
# User.order(:name, email: :desc)
# => SELECT "users".* FROM "users" ORDER BY "users"."name" ASC, "users"."email" DESC
#
# User.order('name')
# => SELECT "users".* FROM "users" ORDER BY name
#
# User.order('name DESC')
# => SELECT "users".* FROM "users" ORDER BY name DESC
#
# User.order('name DESC, email')
# => SELECT "users".* FROM "users" ORDER BY name DESC, email
def order(*args)
check_if_method_has_arguments!(:order, args)
spawn.order!(*args)
end
def order!(*args) # :nodoc:
preprocess_order_args(args)
self.order_values += args
self
end
# Replaces any existing order defined on the relation with the specified order.
#
# User.order('email DESC').reorder('id ASC') # generated SQL has 'ORDER BY id ASC'
#
# Subsequent calls to order on the same relation will be appended. For example:
#
# User.order('email DESC').reorder('id ASC').order('name ASC')
#
# generates a query with 'ORDER BY id ASC, name ASC'.
def reorder(*args)
check_if_method_has_arguments!(:reorder, args)
spawn.reorder!(*args)
end
def reorder!(*args) # :nodoc:
preprocess_order_args(args)
self.reordering_value = true
self.order_values = args
self
end
VALID_UNSCOPING_VALUES = Set.new([:where, :select, :group, :order, :lock,
:limit, :offset, :joins, :includes, :from,
:readonly, :having])
# Removes an unwanted relation that is already defined on a chain of relations.
# This is useful when passing around chains of relations and would like to
# modify the relations without reconstructing the entire chain.
#
# User.order('email DESC').unscope(:order) == User.all
#
# The method arguments are symbols which correspond to the names of the methods
# which should be unscoped. The valid arguments are given in VALID_UNSCOPING_VALUES.
# The method can also be called with multiple arguments. For example:
#
# User.order('email DESC').select('id').where(name: "John")
# .unscope(:order, :select, :where) == User.all
#
# One can additionally pass a hash as an argument to unscope specific :where values.
# This is done by passing a hash with a single key-value pair. The key should be
# :where and the value should be the where value to unscope. For example:
#
# User.where(name: "John", active: true).unscope(where: :name)
# == User.where(active: true)
#
# This method is similar to <tt>except</tt>, but unlike
# <tt>except</tt>, it persists across merges:
#
# User.order('email').merge(User.except(:order))
# == User.order('email')
#
# User.order('email').merge(User.unscope(:order))
# == User.all
#
# This means it can be used in association definitions:
#
# has_many :comments, -> { unscope where: :trashed }
#
def unscope(*args)
check_if_method_has_arguments!(:unscope, args)
spawn.unscope!(*args)
end
def unscope!(*args) # :nodoc:
args.flatten!
self.unscope_values += args
args.each do |scope|
case scope
when Symbol
symbol_unscoping(scope)
when Hash
scope.each do |key, target_value|
if key != :where
raise ArgumentError, "Hash arguments in .unscope(*args) must have :where as the key."
end
target_values = Array(target_value).map(&:to_s)
self.where_clause = where_clause.except(*target_values)
end
else
raise ArgumentError, "Unrecognized scoping: #{args.inspect}. Use .unscope(where: :attribute_name) or .unscope(:order), for example."
end
end
self
end
# Performs a joins on +args+:
#
# User.joins(:posts)
# => SELECT "users".* FROM "users" INNER JOIN "posts" ON "posts"."user_id" = "users"."id"
#
# You can use strings in order to customize your joins:
#
# User.joins("LEFT JOIN bookmarks ON bookmarks.bookmarkable_type = 'Post' AND bookmarks.user_id = users.id")
# => SELECT "users".* FROM "users" LEFT JOIN bookmarks ON bookmarks.bookmarkable_type = 'Post' AND bookmarks.user_id = users.id
def joins(*args)
check_if_method_has_arguments!(:joins, args)
spawn.joins!(*args)
end
def joins!(*args) # :nodoc:
args.compact!
args.flatten!
self.joins_values += args
self
end
# Returns a new relation, which is the result of filtering the current relation
# according to the conditions in the arguments.
#
# #where accepts conditions in one of several formats. In the examples below, the resulting
# SQL is given as an illustration; the actual query generated may be different depending
# on the database adapter.
#
# === string
#
# A single string, without additional arguments, is passed to the query
# constructor as an SQL fragment, and used in the where clause of the query.
#
# Client.where("orders_count = '2'")
# # SELECT * from clients where orders_count = '2';
#
# Note that building your own string from user input may expose your application
# to injection attacks if not done properly. As an alternative, it is recommended
# to use one of the following methods.
#
# === array
#
# If an array is passed, then the first element of the array is treated as a template, and
# the remaining elements are inserted into the template to generate the condition.
# Active Record takes care of building the query to avoid injection attacks, and will
# convert from the ruby type to the database type where needed. Elements are inserted
# into the string in the order in which they appear.
#
# User.where(["name = ? and email = ?", "Joe", "joe@example.com"])
# # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
#
# Alternatively, you can use named placeholders in the template, and pass a hash as the
# second element of the array. The names in the template are replaced with the corresponding
# values from the hash.
#
# User.where(["name = :name and email = :email", { name: "Joe", email: "joe@example.com" }])
# # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
#
# This can make for more readable code in complex queries.
#
# Lastly, you can use sprintf-style % escapes in the template. This works slightly differently
# than the previous methods; you are responsible for ensuring that the values in the template
# are properly quoted. The values are passed to the connector for quoting, but the caller
# is responsible for ensuring they are enclosed in quotes in the resulting SQL. After quoting,
# the values are inserted using the same escapes as the Ruby core method <tt>Kernel::sprintf</tt>.
#
# User.where(["name = '%s' and email = '%s'", "Joe", "joe@example.com"])
# # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
#
# If #where is called with multiple arguments, these are treated as if they were passed as
# the elements of a single array.
#
# User.where("name = :name and email = :email", { name: "Joe", email: "joe@example.com" })
# # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com';
#
# When using strings to specify conditions, you can use any operator available from
# the database. While this provides the most flexibility, you can also unintentionally introduce
# dependencies on the underlying database. If your code is intended for general consumption,
# test with multiple database backends.
#
# === hash
#
# #where will also accept a hash condition, in which the keys are fields and the values
# are values to be searched for.
#
# Fields can be symbols or strings. Values can be single values, arrays, or ranges.
#
# User.where({ name: "Joe", email: "joe@example.com" })
# # SELECT * FROM users WHERE name = 'Joe' AND email = 'joe@example.com'
#
# User.where({ name: ["Alice", "Bob"]})
# # SELECT * FROM users WHERE name IN ('Alice', 'Bob')
#
# User.where({ created_at: (Time.now.midnight - 1.day)..Time.now.midnight })
# # SELECT * FROM users WHERE (created_at BETWEEN '2012-06-09 07:00:00.000000' AND '2012-06-10 07:00:00.000000')
#
# In the case of a belongs_to relationship, an association key can be used
# to specify the model if an ActiveRecord object is used as the value.
#
# author = Author.find(1)
#
# # The following queries will be equivalent:
# Post.where(author: author)
# Post.where(author_id: author)
#
# This also works with polymorphic belongs_to relationships:
#
# treasure = Treasure.create(name: 'gold coins')
# treasure.price_estimates << PriceEstimate.create(price: 125)
#
# # The following queries will be equivalent:
# PriceEstimate.where(estimate_of: treasure)
# PriceEstimate.where(estimate_of_type: 'Treasure', estimate_of_id: treasure)
#
# === Joins
#
# If the relation is the result of a join, you may create a condition which uses any of the
# tables in the join. For string and array conditions, use the table name in the condition.
#
# User.joins(:posts).where("posts.created_at < ?", Time.now)
#
# For hash conditions, you can either use the table name in the key, or use a sub-hash.
#
# User.joins(:posts).where({ "posts.published" => true })
# User.joins(:posts).where({ posts: { published: true } })
#
# === no argument
#
# If no argument is passed, #where returns a new instance of WhereChain, that
# can be chained with #not to return a new relation that negates the where clause.
#
# User.where.not(name: "Jon")
# # SELECT * FROM users WHERE name != 'Jon'
#
# See WhereChain for more details on #not.
#
# === blank condition
#
# If the condition is any blank-ish object, then #where is a no-op and returns
# the current relation.
def where(opts = :chain, *rest)
if opts == :chain
WhereChain.new(spawn)
elsif opts.blank?
self
else
spawn.where!(opts, *rest)
end
end
def where!(opts, *rest) # :nodoc:
if Hash === opts
opts = sanitize_forbidden_attributes(opts)
references!(PredicateBuilder.references(opts))
end
self.where_clause += where_clause_factory.build(opts, rest)
self
end
# Allows you to change a previously set where condition for a given attribute, instead of appending to that condition.
#
# Post.where(trashed: true).where(trashed: false) # => WHERE `trashed` = 1 AND `trashed` = 0
# Post.where(trashed: true).rewhere(trashed: false) # => WHERE `trashed` = 0
# Post.where(active: true).where(trashed: true).rewhere(trashed: false) # => WHERE `active` = 1 AND `trashed` = 0
#
# This is short-hand for unscope(where: conditions.keys).where(conditions). Note that unlike reorder, we're only unscoping
# the named conditions -- not the entire where statement.
def rewhere(conditions)
unscope(where: conditions.keys).where(conditions)
end
# Returns a new relation, which is the logical union of this relation and the one passed as an
# argument.
#
# The two relations must be structurally compatible: they must be scoping the same model, and
# they must differ only by +where+ (if no +group+ has been defined) or +having+ (if a +group+ is
# present). Neither relation may have a +limit+, +offset+, or +distinct+ set.
#
# Post.where("id = 1").or(Post.where("id = 2"))
# # SELECT `posts`.* FROM `posts` WHERE (('id = 1' OR 'id = 2'))
#
def or(other)
spawn.or!(other)
end
def or!(other) # :nodoc:
unless structurally_compatible_for_or?(other)
raise ArgumentError, 'Relation passed to #or must be structurally compatible'
end
self.where_clause = self.where_clause.or(other.where_clause)
self.having_clause = self.having_clause.or(other.having_clause)
self
end
private def structurally_compatible_for_or?(other) # :nodoc:
Relation::SINGLE_VALUE_METHODS.all? { |m| send("#{m}_value") == other.send("#{m}_value") } &&
(Relation::MULTI_VALUE_METHODS - [:extending]).all? { |m| send("#{m}_values") == other.send("#{m}_values") } &&
(Relation::CLAUSE_METHODS - [:having, :where]).all? { |m| send("#{m}_clause") != other.send("#{m}_clause") }
end
# Allows to specify a HAVING clause. Note that you can't use HAVING
# without also specifying a GROUP clause.
#
# Order.having('SUM(price) > 30').group('user_id')
def having(opts, *rest)
opts.blank? ? self : spawn.having!(opts, *rest)
end
def having!(opts, *rest) # :nodoc:
references!(PredicateBuilder.references(opts)) if Hash === opts
self.having_clause += having_clause_factory.build(opts, rest)
self
end
# Specifies a limit for the number of records to retrieve.
#
# User.limit(10) # generated SQL has 'LIMIT 10'
#
# User.limit(10).limit(20) # generated SQL has 'LIMIT 20'
def limit(value)
spawn.limit!(value)
end
def limit!(value) # :nodoc:
self.limit_value = value
self
end
# Specifies the number of rows to skip before returning rows.
#
# User.offset(10) # generated SQL has "OFFSET 10"
#
# Should be used with order.
#
# User.offset(10).order("name ASC")
def offset(value)
spawn.offset!(value)
end
def offset!(value) # :nodoc:
self.offset_value = value
self
end
# Specifies locking settings (default to +true+). For more information
# on locking, please see +ActiveRecord::Locking+.
def lock(locks = true)
spawn.lock!(locks)
end
def lock!(locks = true) # :nodoc:
case locks
when String, TrueClass, NilClass
self.lock_value = locks || true
else
self.lock_value = false
end
self
end
# Returns a chainable relation with zero records.
#
# The returned relation implements the Null Object pattern. It is an
# object with defined null behavior and always returns an empty array of
# records without querying the database.
#
# Any subsequent condition chained to the returned relation will continue
# generating an empty relation and will not fire any query to the database.
#
# Used in cases where a method or scope could return zero records but the
# result needs to be chainable.
#
# For example:
#
# @posts = current_user.visible_posts.where(name: params[:name])
# # => the visible_posts method is expected to return a chainable Relation
#
# def visible_posts
# case role
# when 'Country Manager'
# Post.where(country: country)
# when 'Reviewer'
# Post.published
# when 'Bad User'
# Post.none # It can't be chained if [] is returned.
# end
# end
#
def none
where("1=0").extending!(NullRelation)
end
def none! # :nodoc:
where!("1=0").extending!(NullRelation)
end
# Sets readonly attributes for the returned relation. If value is
# true (default), attempting to update a record will result in an error.
#
# users = User.readonly
# users.first.save
# => ActiveRecord::ReadOnlyRecord: ActiveRecord::ReadOnlyRecord
def readonly(value = true)
spawn.readonly!(value)
end
def readonly!(value = true) # :nodoc:
self.readonly_value = value
self
end
# Sets attributes to be used when creating new records from a
# relation object.
#
# users = User.where(name: 'Oscar')
# users.new.name # => 'Oscar'
#
# users = users.create_with(name: 'DHH')
# users.new.name # => 'DHH'
#
# You can pass +nil+ to +create_with+ to reset attributes:
#
# users = users.create_with(nil)
# users.new.name # => 'Oscar'
def create_with(value)
spawn.create_with!(value)
end
def create_with!(value) # :nodoc:
if value
value = sanitize_forbidden_attributes(value)
self.create_with_value = create_with_value.merge(value)
else
self.create_with_value = {}
end
self
end
# Specifies table from which the records will be fetched. For example:
#
# Topic.select('title').from('posts')
# # => SELECT title FROM posts
#
# Can accept other relation objects. For example:
#
# Topic.select('title').from(Topic.approved)
# # => SELECT title FROM (SELECT * FROM topics WHERE approved = 't') subquery
#
# Topic.select('a.title').from(Topic.approved, :a)
# # => SELECT a.title FROM (SELECT * FROM topics WHERE approved = 't') a
#
def from(value, subquery_name = nil)
spawn.from!(value, subquery_name)
end
def from!(value, subquery_name = nil) # :nodoc:
self.from_clause = Relation::FromClause.new(value, subquery_name)
self
end
# Specifies whether the records should be unique or not. For example:
#
# User.select(:name)
# # => Might return two records with the same name
#
# User.select(:name).distinct
# # => Returns 1 record per distinct name
#
# User.select(:name).distinct.distinct(false)
# # => You can also remove the uniqueness
def distinct(value = true)
spawn.distinct!(value)
end
alias uniq distinct
deprecate uniq: :distinct
# Like #distinct, but modifies relation in place.
def distinct!(value = true) # :nodoc:
self.distinct_value = value
self
end
alias uniq! distinct!
deprecate uniq!: :distinct!
# Used to extend a scope with additional methods, either through
# a module or through a block provided.
#
# The object returned is a relation, which can be further extended.
#
# === Using a module
#
# module Pagination
# def page(number)
# # pagination code goes here
# end
# end
#
# scope = Model.all.extending(Pagination)
# scope.page(params[:page])
#
# You can also pass a list of modules:
#
# scope = Model.all.extending(Pagination, SomethingElse)
#
# === Using a block
#
# scope = Model.all.extending do
# def page(number)
# # pagination code goes here
# end
# end
# scope.page(params[:page])
#
# You can also use a block and a module list:
#
# scope = Model.all.extending(Pagination) do
# def per_page(number)
# # pagination code goes here
# end
# end
def extending(*modules, &block)
if modules.any? || block
spawn.extending!(*modules, &block)
else
self
end
end
def extending!(*modules, &block) # :nodoc:
modules << Module.new(&block) if block
modules.flatten!
self.extending_values += modules
extend(*extending_values) if extending_values.any?
self
end
# Reverse the existing order clause on the relation.
#
# User.order('name ASC').reverse_order # generated SQL has 'ORDER BY name DESC'
def reverse_order
spawn.reverse_order!
end
def reverse_order! # :nodoc:
orders = order_values.uniq
orders.reject!(&:blank?)
self.order_values = reverse_sql_order(orders)
self
end
# Returns the Arel object associated with the relation.
def arel # :nodoc:
@arel ||= build_arel
end
private
def assert_mutability!
raise ImmutableRelation if @loaded
raise ImmutableRelation if defined?(@arel) && @arel
end
def build_arel
arel = Arel::SelectManager.new(table)
build_joins(arel, joins_values.flatten) unless joins_values.empty?
arel.where(where_clause.ast) unless where_clause.empty?
arel.having(having_clause.ast) unless having_clause.empty?
arel.take(connection.sanitize_limit(limit_value)) if limit_value
arel.skip(offset_value.to_i) if offset_value
arel.group(*arel_columns(group_values.uniq.reject(&:blank?))) unless group_values.empty?
build_order(arel)
build_select(arel)
arel.distinct(distinct_value)
arel.from(build_from) unless from_clause.empty?
arel.lock(lock_value) if lock_value
arel
end
def symbol_unscoping(scope)
if !VALID_UNSCOPING_VALUES.include?(scope)
raise ArgumentError, "Called unscope() with invalid unscoping argument ':#{scope}'. Valid arguments are :#{VALID_UNSCOPING_VALUES.to_a.join(", :")}."
end
clause_method = Relation::CLAUSE_METHODS.include?(scope)
multi_val_method = Relation::MULTI_VALUE_METHODS.include?(scope)
if clause_method
unscope_code = "#{scope}_clause="
else
unscope_code = "#{scope}_value#{'s' if multi_val_method}="
end
case scope
when :order
result = []
else
result = [] if multi_val_method
end
self.send(unscope_code, result)
end
def association_for_table(table_name)
table_name = table_name.to_s
@klass._reflect_on_association(table_name) ||
@klass._reflect_on_association(table_name.singularize)
end
def build_from
opts = from_clause.value
name = from_clause.name
case opts
when Relation
name ||= 'subquery'
opts.arel.as(name.to_s)
else
opts
end
end
def build_joins(manager, joins)
buckets = joins.group_by do |join|
case join
when String
:string_join
when Hash, Symbol, Array
:association_join
when ActiveRecord::Associations::JoinDependency
:stashed_join
when Arel::Nodes::Join
:join_node
else
raise 'unknown class: %s' % join.class.name
end
end
buckets.default = []
association_joins = buckets[:association_join]
stashed_association_joins = buckets[:stashed_join]
join_nodes = buckets[:join_node].uniq
string_joins = buckets[:string_join].map(&:strip).uniq
join_list = join_nodes + convert_join_strings_to_ast(manager, string_joins)
join_dependency = ActiveRecord::Associations::JoinDependency.new(
@klass,
association_joins,
join_list
)
join_infos = join_dependency.join_constraints stashed_association_joins
join_infos.each do |info|
info.joins.each { |join| manager.from(join) }
manager.bind_values.concat info.binds
end
manager.join_sources.concat(join_list)
manager
end
def convert_join_strings_to_ast(table, joins)
joins
.flatten
.reject(&:blank?)
.map { |join| table.create_string_join(Arel.sql(join)) }
end
def build_select(arel)
if select_values.any?
arel.project(*arel_columns(select_values.uniq))
else
arel.project(@klass.arel_table[Arel.star])
end
end
def arel_columns(columns)
columns.map do |field|
if (Symbol === field || String === field) && columns_hash.key?(field.to_s) && !from_clause.value
arel_table[field]
elsif Symbol === field
connection.quote_table_name(field.to_s)
else
field
end
end
end
def reverse_sql_order(order_query)
order_query = ["#{quoted_table_name}.#{quoted_primary_key} ASC"] if order_query.empty?
order_query.flat_map do |o|
case o
when Arel::Nodes::Ordering
o.reverse
when String
o.to_s.split(',').map! do |s|
s.strip!
s.gsub!(/\sasc\Z/i, ' DESC') || s.gsub!(/\sdesc\Z/i, ' ASC') || s.concat(' DESC')
end
else
o
end
end
end
def build_order(arel)
orders = order_values.uniq
orders.reject!(&:blank?)
arel.order(*orders) unless orders.empty?
end
VALID_DIRECTIONS = [:asc, :desc, :ASC, :DESC,
'asc', 'desc', 'ASC', 'DESC'] # :nodoc:
def validate_order_args(args)
args.each do |arg|
next unless arg.is_a?(Hash)
arg.each do |_key, value|
raise ArgumentError, "Direction \"#{value}\" is invalid. Valid " \
"directions are: #{VALID_DIRECTIONS.inspect}" unless VALID_DIRECTIONS.include?(value)
end
end
end
def preprocess_order_args(order_args)
order_args.flatten!
validate_order_args(order_args)
references = order_args.grep(String)
references.map! { |arg| arg =~ /^([a-zA-Z]\w*)\.(\w+)/ && $1 }.compact!
references!(references) if references.any?
# if a symbol is given we prepend the quoted table name
order_args.map! do |arg|
case arg
when Symbol
arg = klass.attribute_alias(arg) if klass.attribute_alias?(arg)
table[arg].asc
when Hash
arg.map { |field, dir|
field = klass.attribute_alias(field) if klass.attribute_alias?(field)
table[field].send(dir.downcase)
}
else
arg
end
end.flatten!
end
# Checks to make sure that the arguments are not blank. Note that if some
# blank-like object were initially passed into the query method, then this
# method will not raise an error.
#
# Example:
#
# Post.references() # => raises an error
# Post.references([]) # => does not raise an error
#
# This particular method should be called with a method_name and the args
# passed into that method as an input. For example:
#
# def references(*args)
# check_if_method_has_arguments!("references", args)
# ...
# end
def check_if_method_has_arguments!(method_name, args)
if args.blank?
raise ArgumentError, "The method .#{method_name}() must contain arguments."
end
end
def new_where_clause
Relation::WhereClause.empty
end
alias new_having_clause new_where_clause
def where_clause_factory
@where_clause_factory ||= Relation::WhereClauseFactory.new(klass, predicate_builder)
end
alias having_clause_factory where_clause_factory
def new_from_clause
Relation::FromClause.empty
end
end
end
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