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-rw-r--r--activerecord/lib/active_record/associations.rb33
1 files changed, 22 insertions, 11 deletions
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 7ec7eb1b24..945f22d3c8 100644
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1052,7 +1052,7 @@ module ActiveRecord
# Specifies a one-to-many association. The following methods for retrieval and query of
# collections of associated objects will be added:
#
- # +collection+ is a placeholder for the symbol passed as the first argument, so
+ # +collection+ is a placeholder for the symbol passed as the +name+ argument, so
# <tt>has_many :clients</tt> would add among others <tt>clients.empty?</tt>.
#
# [collection(force_reload = false)]
@@ -1131,7 +1131,7 @@ module ActiveRecord
# * <tt>Firm#clients.build</tt> (similar to <tt>Client.new("firm_id" => id)</tt>)
# * <tt>Firm#clients.create</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save; c</tt>)
# * <tt>Firm#clients.create!</tt> (similar to <tt>c = Client.new("firm_id" => id); c.save!</tt>)
- # The declaration can also include an options hash to specialize the behavior of the association.
+ # The declaration can also include an +options+ hash to specialize the behavior of the association.
#
# === Options
# [:class_name]
@@ -1209,7 +1209,7 @@ module ActiveRecord
# Option examples:
# has_many :comments, -> { order "posted_on" }
# has_many :comments, -> { includes :author }
- # has_many :people, -> { where("deleted = 0").order("name") }, class_name: "Person"
+ # has_many :people, -> { where(deleted: false).order("name") }, class_name: "Person"
# has_many :tracks, -> { order "position" }, dependent: :destroy
# has_many :comments, dependent: :nullify
# has_many :tags, as: :taggable
@@ -1227,7 +1227,7 @@ module ActiveRecord
#
# The following methods for retrieval and query of a single associated object will be added:
#
- # +association+ is a placeholder for the symbol passed as the first argument, so
+ # +association+ is a placeholder for the symbol passed as the +name+ argument, so
# <tt>has_one :manager</tt> would add among others <tt>manager.nil?</tt>.
#
# [association(force_reload = false)]
@@ -1259,7 +1259,7 @@ module ActiveRecord
#
# === Options
#
- # The declaration can also include an options hash to specialize the behavior of the association.
+ # The declaration can also include an +options+ hash to specialize the behavior of the association.
#
# Options are:
# [:class_name]
@@ -1338,7 +1338,7 @@ module ActiveRecord
# Methods will be added for retrieval and query for a single associated object, for which
# this object holds an id:
#
- # +association+ is a placeholder for the symbol passed as the first argument, so
+ # +association+ is a placeholder for the symbol passed as the +name+ argument, so
# <tt>belongs_to :author</tt> would add among others <tt>author.nil?</tt>.
#
# [association(force_reload = false)]
@@ -1364,7 +1364,18 @@ module ActiveRecord
# * <tt>Post#build_author</tt> (similar to <tt>post.author = Author.new</tt>)
# * <tt>Post#create_author</tt> (similar to <tt>post.author = Author.new; post.author.save; post.author</tt>)
# * <tt>Post#create_author!</tt> (similar to <tt>post.author = Author.new; post.author.save!; post.author</tt>)
- # The declaration can also include an options hash to specialize the behavior of the association.
+ # The declaration can also include an +options+ hash to specialize the behavior of the association.
+ #
+ # === Scopes
+ #
+ # You can pass a second argument +scope+ as a callable (i.e. proc or
+ # lambda) to retrieve a specific record or customize the generated query
+ # when you access the associated object.
+ #
+ # Scope examples:
+ # belongs_to :user, -> { where(id: 2) }
+ # belongs_to :user, -> { joins(:friends) }
+ # belongs_to :level, ->(level) { where("game_level > ?", level.current) }
#
# === Options
#
@@ -1418,7 +1429,7 @@ module ActiveRecord
#
# Note that <tt>accepts_nested_attributes_for</tt> sets <tt>:autosave</tt> to <tt>true</tt>.
# [:touch]
- # If true, the associated object will be touched (the updated_at/on attributes set to now)
+ # If true, the associated object will be touched (the updated_at/on attributes set to current time)
# when this record is either saved or destroyed. If you specify a symbol, that attribute
# will be updated with the current time in addition to the updated_at/on attribute.
# [:inverse_of]
@@ -1435,7 +1446,7 @@ module ActiveRecord
# belongs_to :firm, foreign_key: "client_of"
# belongs_to :person, primary_key: "name", foreign_key: "person_name"
# belongs_to :author, class_name: "Person", foreign_key: "author_id"
- # belongs_to :valid_coupon, ->(o) { where "discounts > #{o.payments_count}" },
+ # belongs_to :valid_coupon, ->(o) { where "discounts > ?", o.payments_count },
# class_name: "Coupon", foreign_key: "coupon_id"
# belongs_to :attachable, polymorphic: true
# belongs_to :project, readonly: true
@@ -1480,7 +1491,7 @@ module ActiveRecord
#
# Adds the following methods for retrieval and query:
#
- # +collection+ is a placeholder for the symbol passed as the first argument, so
+ # +collection+ is a placeholder for the symbol passed as the +name+ argument, so
# <tt>has_and_belongs_to_many :categories</tt> would add among others <tt>categories.empty?</tt>.
#
# [collection(force_reload = false)]
@@ -1541,7 +1552,7 @@ module ActiveRecord
# * <tt>Developer#projects.exists?(...)</tt>
# * <tt>Developer#projects.build</tt> (similar to <tt>Project.new("developer_id" => id)</tt>)
# * <tt>Developer#projects.create</tt> (similar to <tt>c = Project.new("developer_id" => id); c.save; c</tt>)
- # The declaration may include an options hash to specialize the behavior of the association.
+ # The declaration may include an +options+ hash to specialize the behavior of the association.
#
# === Options
#