Allow configuration of embedded models to fire callbacks on parent save (#237)

lib/mongoid/callbacks.rb

@@ -21,5 +21,54 @@ module Callbacks
       define_model_callbacks :initialize, :only => :after
       define_model_callbacks :create, :destroy, :save, :update
     end
+
+    def run_callbacks(kind, *args, &block)
+      _run_callbacks_with_cascade(_cascade_targets(kind), kind, *args) do
+        super(kind, *args, &block)
+      end
+    end
+
+    protected
+
+    def _cascade_targets(kind)
+      cascadable_children = []
+      self.relations.each_pair do |name, metadata|
+        next unless metadata.embedded? && metadata.cascade_callbacks
+
+        target = self.send(name)
+
+        if metadata.macro == :embeds_many
+          cascadable_children += target
+        elsif metadata.macro == :embeds_one && target.present?
+          cascadable_children << target
+        end
+      end
+      cascadable_children.select { |child| _should_cascade(kind, child) }
+    end
+
+    def _should_cascade(kind, child)
+      [:create, :destroy].include?(kind) || child.changed? || child.new_record?
+    end
+
+    def _normalize_callback_kind(original_kind, child)
+      if original_kind == :update && child.new_record?
+        :create
+      else
+        original_kind
+      end
+    end
+
+    def _run_callbacks_with_cascade(children, kind, *args, &block)
+      if child = children.pop
+        _run_callbacks_with_cascade(children, kind, *args) do
+          kind = _normalize_callback_kind(kind, child)
+          child.run_callbacks(kind, *args) do
+            block.call
+          end
+        end
+      else
+        block.call
+      end
+    end
   end
 end

lib/mongoid/relations/embedded/many.rb

@@ -499,7 +499,7 @@ def stores_foreign_key?
           #
           # @since 2.1.0
           def valid_options
-            [ :as, :cyclic, :order, :versioned ]
+            [ :as, :cyclic, :order, :versioned, :cascade_callbacks ]
           end
 
           # Get the default validation setting for the relation. Determines if

lib/mongoid/relations/embedded/one.rb

@@ -183,7 +183,7 @@ def stores_foreign_key?
           #
           # @since 2.1.0
           def valid_options
-            [ :as, :cyclic ]
+            [ :as, :cyclic, :cascade_callbacks ]
           end
 
           # Get the default validation setting for the relation. Determines if

lib/mongoid/relations/metadata.rb

@@ -719,6 +719,18 @@ def order?
         !!order
       end
 
+      # Should embedded association cascade parent callbacks?
+      #
+      # @example Perform parent callbacks cascading?
+      #   metadata.cascade_callbacks
+      #
+      # @return [ true, false ] If the cascade_callbacks is set.
+      #
+      # @since 2.1.0
+      def cascade_callbacks
+        !!self[:cascade_callbacks]
+      end
+
       private
 
       # Returns the class name for the relation.

spec/models/callbacks.rb

@@ -2,7 +2,9 @@ class Artist
   include Mongoid::Document
   field :name
   embeds_many :songs
-  embeds_many :labels
+  embeds_many :labels, :cascade_callbacks => true
+  embeds_one  :instrument, :cascade_callbacks => true
+  embeds_one  :address
 
   before_create :before_create_stub
   after_create :create_songs
@@ -27,10 +29,48 @@ def create_songs
   end
 end
 
+class Address
+  include Mongoid::Document
+  field :street
+  embedded_in :artist
+
+  after_save :after_save_stub
+
+  private
+  def after_save_stub
+  end
+end
+
+class Instrument
+  include Mongoid::Document
+  field :name
+  field :key
+  embedded_in :artist
+
+  after_save :after_save_stub
+  before_create :upcase_name
+  before_update :tune_to_g_sharp
+
+  private
+  def after_save_stub; end
+  def upcase_name
+    self.name = self.name.upcase
+  end
+  def tune_to_g_sharp
+    self.key = "G#"
+  end
+end
+
 class Song
   include Mongoid::Document
   field :title
   embedded_in :artist
+
+  after_save :after_save_stub
+
+  private
+  def after_save_stub
+  end
 end
 
 class Label
@@ -39,10 +79,15 @@ class Label
   embedded_in :artist
   before_validation :cleanup
 
+  after_save :after_save_stub
+
   private
   def cleanup
     self.name = self.name.downcase.capitalize
   end
+
+  def after_save_stub
+  end
 end
 
 class ValidationCallback

spec/unit/mongoid/callbacks_spec.rb

@@ -84,6 +84,125 @@ class TestClass
     end
   end
 
+  describe "cascaded callbacks" do
+
+    let(:artist) do
+      Artist.new(:name => "Foo Fighters")
+    end
+
+    context "on parent update" do
+
+      before do
+        artist.save!
+        artist.build_instrument(:name => "Piano")
+      end
+
+      context "child is new" do
+
+        it "should trigger create" do
+          artist.save!
+          artist.instrument.name.should == 'PIANO'
+        end
+
+        it "should not trigger update" do
+          artist.save!
+          artist.instrument.key.should_not == 'G#'
+        end
+      end
+
+      context "child is persisted" do
+
+        before do
+          artist.save!
+        end
+
+        context "child is dirty" do
+
+          before do
+            artist.instrument.name = 'Tuba'
+          end
+
+          it "should trigger update" do
+            artist.save!
+            artist.instrument.key.should == 'G#'
+          end
+        end
+
+        context "child is not dirty" do
+
+          it "should not trigger update" do
+            artist.save!
+            artist.instrument.key.should_not == 'G#'
+          end
+        end
+      end
+    end
+
+    context "when enabled" do
+
+      let(:label) do
+        Label.new(:name => "Tower Records")
+      end
+
+      let(:instrument) do
+        Instrument.new(:name => "Harpsichord")
+      end
+
+      before do
+        artist.labels << label
+        artist.instrument = instrument
+      end
+
+      context "embeds_many" do
+
+        it "should cascade callbacks" do
+          label.expects(:after_save_stub)
+          artist.save!
+        end
+      end
+
+      context "embeds_one" do
+
+        it "should cascade callbacks" do
+          instrument.expects(:after_save_stub)
+          artist.save!
+        end
+      end
+    end
+
+    context "when disabled" do
+
+      let(:song) do
+        Song.new
+      end
+
+      let(:address) do
+        Address.new
+      end
+
+      before do
+        artist.songs << song
+        artist.address = address
+      end
+
+      context "embeds_many" do
+
+        it "should not cascade callbacks" do
+          song.expects(:after_save_stub).never
+          artist.save!
+        end
+      end
+
+      context "embeds_one" do
+
+        it "should not cascade callbacks" do
+          address.expects(:after_save_stub).never
+          artist.save!
+        end
+      end
+    end
+  end
+
   describe ".before_create" do
 
     before do

spec/unit/mongoid/relations/embedded/many_spec.rb

@@ -591,7 +591,7 @@
 
     it "returns the valid options" do
       described_class.valid_options.should ==
-        [ :as, :cyclic, :order, :versioned ]
+        [ :as, :cyclic, :order, :versioned, :cascade_callbacks ]
     end
   end
 

spec/unit/mongoid/relations/embedded/one_spec.rb

@@ -126,7 +126,7 @@
 
     it "returns the valid options" do
       described_class.valid_options.should ==
-        [ :as, :cyclic ]
+        [ :as, :cyclic, :cascade_callbacks ]
     end
   end