Changed API of NestedAttributes to take an array, or hash with index keys, of hashes that have the id on the inside of the attributes hash and updated the FormBuilder to produce such hashes. Also fixed NestedAttributes with composite ids.

Signed-off-by: Michael Koziarski <michael@koziarski.com>
Signed-off-by: Eloy Duran <eloy.de.enige@gmail.com>
[#1892 state:committed]

1 files changed, 146 insertions, 100 deletions

diff --git a/activerecord/lib/active_record/nested_attributes.rb b/activerecord/lib/active_record/nested_attributes.rb
index 5778223c74..e3122d195a 100644
--- a/activerecord/lib/active_record/nested_attributes.rb
+++ b/activerecord/lib/active_record/nested_attributes.rb
@@ -41,15 +41,16 @@ module ActiveRecord
     # Enabling nested attributes on a one-to-one association allows you to
     # create the member and avatar in one go:
     #
-    #   params = { 'member' => { 'name' => 'Jack', 'avatar_attributes' => { 'icon' => 'smiling' } } }
+    #   params = { :member => { :name => 'Jack', :avatar_attributes => { :icon => 'smiling' } } }
     #   member = Member.create(params)
-    #   member.avatar.icon #=> 'smiling'
+    #   member.avatar.id # => 2
+    #   member.avatar.icon # => 'smiling'
     #
     # It also allows you to update the avatar through the member:
     #
-    #   params = { 'member' => { 'avatar_attributes' => { 'icon' => 'sad' } } }
+    #   params = { :member' => { :avatar_attributes => { :id => '2', :icon => 'sad' } } }
     #   member.update_attributes params['member']
-    #   member.avatar.icon #=> 'sad'
+    #   member.avatar.icon # => 'sad'
     #
     # By default you will only be able to set and update attributes on the
     # associated model. If you want to destroy the associated model through the
@@ -64,7 +65,7 @@ module ActiveRecord
     # Now, when you add the <tt>_delete</tt> key to the attributes hash, with a
     # value that evaluates to +true+, you will destroy the associated model:
     #
-    #   member.avatar_attributes = { '_delete' => '1' }
+    #   member.avatar_attributes = { :id => '2', :_delete => '1' }
     #   member.avatar.marked_for_destruction? # => true
     #   member.save
     #   member.avatar #=> nil
@@ -77,59 +78,80 @@ module ActiveRecord
     #
     #   class Member < ActiveRecord::Base
     #     has_many :posts
-    #     accepts_nested_attributes_for :posts, :reject_if => proc { |attributes| attributes['title'].blank? }
+    #     accepts_nested_attributes_for :posts
     #   end
     #
     # You can now set or update attributes on an associated post model through
     # the attribute hash.
     #
-    # For each key in the hash that starts with the string 'new' a new model
-    # will be instantiated. When the proc given with the <tt>:reject_if</tt>
-    # option evaluates to +false+ for a certain attribute hash no record will
-    # be built for that hash. (Rejecting new records can alternatively be done
-    # by utilizing the <tt>'_delete'</tt> key. Scroll down for more info.)
-    #
-    #   params = { 'member' => {
-    #     'name' => 'joe', 'posts_attributes' => {
-    #       'new_12345' => { 'title' => 'Kari, the awesome Ruby documentation browser!' },
-    #       'new_54321' => { 'title' => 'The egalitarian assumption of the modern citizen' },
-    #       'new_67890' => { 'title' => '' } # This one matches the :reject_if proc and will not be instantiated.
-    #     }
+    # For each hash that does _not_ have an <tt>id</tt> key a new record will
+    # be instantiated, unless the hash also contains a <tt>_delete</tt> key
+    # that evaluates to +true+.
+    #
+    #   params = { :member => {
+    #     :name => 'joe', :posts_attributes => [
+    #       { :title => 'Kari, the awesome Ruby documentation browser!' },
+    #       { :title => 'The egalitarian assumption of the modern citizen' },
+    #       { :title => '', :_delete => '1' } # this will be ignored
+    #     ]
     #   }}
     #
     #   member = Member.create(params['member'])
-    #   member.posts.length #=> 2
-    #   member.posts.first.title #=> 'Kari, the awesome Ruby documentation browser!'
-    #   member.posts.second.title #=> 'The egalitarian assumption of the modern citizen'
+    #   member.posts.length # => 2
+    #   member.posts.first.title # => 'Kari, the awesome Ruby documentation browser!'
+    #   member.posts.second.title # => 'The egalitarian assumption of the modern citizen'
+    #
+    # You may also set a :reject_if proc to silently ignore any new record
+    # hashes if they fail to pass your criteria. For example, the previous
+    # example could be rewritten as:
+    #
+    #    class Member < ActiveRecord::Base
+    #      has_many :posts
+    #      accepts_nested_attributes_for :posts, :reject_if => proc { |attributes| attributes['title'].blank? }
+    #    end
+    #
+    #   params = { :member => {
+    #     :name => 'joe', :posts_attributes => [
+    #       { :title => 'Kari, the awesome Ruby documentation browser!' },
+    #       { :title => 'The egalitarian assumption of the modern citizen' },
+    #       { :title => '' } # this will be ignored because of the :reject_if proc
+    #     ]
+    #   }}
+    #
+    #   member = Member.create(params['member'])
+    #   member.posts.length # => 2
+    #   member.posts.first.title # => 'Kari, the awesome Ruby documentation browser!'
+    #   member.posts.second.title # => 'The egalitarian assumption of the modern citizen'
     #
-    # When the key for post attributes is an integer, the associated post with
-    # that ID will be updated:
+    # If the hash contains an <tt>id</tt> key that matches an already
+    # associated record, the matching record will be modified:
     #
     #   member.attributes = {
-    #     'name' => 'Joe',
-    #     'posts_attributes' => {
-    #       '1' => { 'title' => '[UPDATED] An, as of yet, undisclosed awesome Ruby documentation browser!' },
-    #       '2' => { 'title' => '[UPDATED] other post' }
-    #     }
+    #     :name => 'Joe',
+    #     :posts_attributes => [
+    #       { :id => 1, :title => '[UPDATED] An, as of yet, undisclosed awesome Ruby documentation browser!' },
+    #       { :id => 2, :title => '[UPDATED] other post' }
+    #     ]
     #   }
     #
-    # By default the associated models are protected from being destroyed. If
-    # you want to destroy any of the associated models through the attributes
-    # hash, you have to enable it first using the <tt>:allow_destroy</tt>
-    # option.
+    #   member.posts.first.title # => '[UPDATED] An, as of yet, undisclosed awesome Ruby documentation browser!'
+    #   member.posts.second.title # => '[UPDATED] other post'
     #
-    # This will allow you to specify which models to destroy in the attributes
-    # hash by setting the '_delete' attribute to a value that evaluates to
-    # +true+:
+    # By default the associated records are protected from being destroyed. If
+    # you want to destroy any of the associated records through the attributes
+    # hash, you have to enable it first using the <tt>:allow_destroy</tt>
+    # option. This will allow you to also use the <tt>_delete</tt> key to
+    # destroy existing records:
     #
     #   class Member < ActiveRecord::Base
     #     has_many :posts
     #     accepts_nested_attributes_for :posts, :allow_destroy => true
     #   end
     #
-    #   params = {'member' => { 'name' => 'joe', 'posts_attributes' => {
-    #     '2' => { '_delete' => '1' }
-    #   }}}
+    #   params = { :member => {
+    #     :posts_attributes => [{ :id => '2', :_delete => '1' }]
+    #   }}
+    #
     #   member.attributes = params['member']
     #   member.posts.detect { |p| p.id == 2 }.marked_for_destruction? # => true
     #   member.posts.length #=> 2
@@ -143,24 +165,27 @@ module ActiveRecord
     # the parent model is saved. This happens inside the transaction initiated
     # by the parents save method. See ActiveRecord::AutosaveAssociation.
     module ClassMethods
-      # Defines an attributes writer for the specified association(s).
+      # Defines an attributes writer for the specified association(s). If you
+      # are using <tt>attr_protected</tt> or <tt>attr_accessible</tt>, then you
+      # will need to add the attribute writer to the allowed list.
       #
       # Supported options:
       # [:allow_destroy]
       #   If true, destroys any members from the attributes hash with a
-      #   <tt>_delete</tt> key and a value that converts to +true+
+      #   <tt>_delete</tt> key and a value that evaluates to +true+
       #   (eg. 1, '1', true, or 'true'). This option is off by default.
       # [:reject_if]
       #   Allows you to specify a Proc that checks whether a record should be
       #   built for a certain attribute hash. The hash is passed to the Proc
       #   and the Proc should return either +true+ or +false+. When no Proc
-      #   is specified a record will be built for all attribute hashes.
+      #   is specified a record will be built for all attribute hashes that
+      #   do not have a <tt>_delete</tt> that evaluates to true.
       #
       # Examples:
-      #   accepts_nested_attributes_for :avatar
-      #   accepts_nested_attributes_for :avatar, :allow_destroy => true
-      #   accepts_nested_attributes_for :avatar, :reject_if => proc { ... }
-      #   accepts_nested_attributes_for :avatar, :posts, :allow_destroy => true, :reject_if => proc { ... }
+      #   # creates avatar_attributes=
+      #   accepts_nested_attributes_for :avatar, :reject_if => proc { |attributes| attributes['name'].blank? }
+      #   # creates avatar_attributes= and posts_attributes=
+      #   accepts_nested_attributes_for :avatar, :posts, :allow_destroy => true
       def accepts_nested_attributes_for(*attr_names)
         options = { :allow_destroy => false }
         options.update(attr_names.extract_options!)
@@ -193,9 +218,9 @@ module ActiveRecord
       end
     end
 
-    # Returns ActiveRecord::AutosaveAssociation::marked_for_destruction?
-    # It's used in conjunction with fields_for to build a form element
-    # for the destruction of this association.
+    # Returns ActiveRecord::AutosaveAssociation::marked_for_destruction? It's
+    # used in conjunction with fields_for to build a form element for the
+    # destruction of this association.
     #
     # See ActionView::Helpers::FormHelper::fields_for for more info.
     def _delete
@@ -204,80 +229,101 @@ module ActiveRecord
 
     private
 
-    # Assigns the given attributes to the association. An association will be
-    # build if it doesn't exist yet.
+    # Attribute hash keys that should not be assigned as normal attributes.
+    # These hash keys are nested attributes implementation details.
+    UNASSIGNABLE_KEYS = %w{ id _delete }
+
+    # Assigns the given attributes to the association.
+    #
+    # If the given attributes include an <tt>:id</tt> that matches the existing
+    # record’s id, then the existing record will be modified. Otherwise a new
+    # record will be built.
+    #
+    # If the given attributes include a matching <tt>:id</tt> attribute _and_ a
+    # <tt>:_delete</tt> key set to a truthy value, then the existing record
+    # will be marked for destruction.
     def assign_nested_attributes_for_one_to_one_association(association_name, attributes, allow_destroy)
-      if should_destroy_nested_attributes_record?(allow_destroy, attributes)
-        send(association_name).mark_for_destruction
-      else
-        (send(association_name) || send("build_#{association_name}")).attributes = attributes
+      attributes = attributes.stringify_keys
+
+      if attributes['id'].blank?
+        unless reject_new_record?(association_name, attributes)
+          send("build_#{association_name}", attributes.except(*UNASSIGNABLE_KEYS))
+        end
+      elsif (existing_record = send(association_name)) && existing_record.id.to_s == attributes['id'].to_s
+        assign_to_or_mark_for_destruction(existing_record, attributes, allow_destroy)
       end
     end
 
     # Assigns the given attributes to the collection association.
     #
-    # Keys containing an ID for an associated record will update that record.
-    # Keys starting with <tt>new</tt> will instantiate a new record for that
-    # association.
+    # Hashes with an <tt>:id</tt> value matching an existing associated record
+    # will update that record. Hashes without an <tt>:id</tt> value will build
+    # a new record for the association. Hashes with a matching <tt>:id</tt>
+    # value and a <tt>:_delete</tt> key set to a truthy value will mark the
+    # matched record for destruction.
     #
     # For example:
     #
     #   assign_nested_attributes_for_collection_association(:people, {
-    #     '1' => { 'name' => 'Peter' },
-    #     'new_43' => { 'name' => 'John' }
+    #     '1' => { :id => '1', :name => 'Peter' },
+    #     '2' => { :name => 'John' },
+    #     '3' => { :id => '2', :_delete => true }
     #   })
     #
-    # Will update the name of the Person with ID 1 and create a new associated
-    # person with the name 'John'.
-    def assign_nested_attributes_for_collection_association(association_name, attributes, allow_destroy)
-      unless attributes.is_a?(Hash)
-        raise ArgumentError, "Hash expected, got #{attributes.class.name} (#{attributes.inspect})"
+    # Will update the name of the Person with ID 1, build a new associated
+    # person with the name `John', and mark the associatied Person with ID 2
+    # for destruction.
+    #
+    # Also accepts an Array of attribute hashes:
+    #
+    #   assign_nested_attributes_for_collection_association(:people, [
+    #     { :id => '1', :name => 'Peter' },
+    #     { :name => 'John' },
+    #     { :id => '2', :_delete => true }
+    #   ])
+    def assign_nested_attributes_for_collection_association(association_name, attributes_collection, allow_destroy)
+      unless attributes_collection.is_a?(Hash) || attributes_collection.is_a?(Array)
+        raise ArgumentError, "Hash or Array expected, got #{attributes_collection.class.name} (#{attributes_collection.inspect})"
       end
 
-      # Make sure any new records sorted by their id before they're build.
-      sorted_by_id = attributes.sort_by { |id, _| id.is_a?(String) ? id.sub(/^new_/, '').to_i : id }
-
-      sorted_by_id.each do |id, record_attributes|
-        if id.acts_like?(:string) && id.starts_with?('new_')
-          build_new_nested_attributes_record(association_name, record_attributes)
-        else
-          assign_to_or_destroy_nested_attributes_record(association_name, id, record_attributes, allow_destroy)
-        end
+      if attributes_collection.is_a? Hash
+        attributes_collection = attributes_collection.sort_by { |index, _| index.to_i }.map { |_, attributes| attributes }
       end
-    end
 
-    # Returns +true+ if <tt>allow_destroy</tt> is enabled and the attributes
-    # contains a truthy value for the key <tt>'_delete'</tt>.
-    #
-    # It will _always_ remove the <tt>'_delete'</tt> key, if present.
-    def should_destroy_nested_attributes_record?(allow_destroy, attributes)
-      ConnectionAdapters::Column.value_to_boolean(attributes.delete('_delete')) && allow_destroy
-    end
+      attributes_collection.each do |attributes|
+        attributes = attributes.stringify_keys
 
-    # Builds a new record with the given attributes.
-    #
-    # If a <tt>:reject_if</tt> proc exists for this association, it will be
-    # called with the attributes as its argument. If the proc returns a truthy
-    # value, the record is _not_ build.
-    #
-    # Alternatively, you can specify the <tt>'_delete'</tt> key to _not_ build
-    # a record. See should_destroy_nested_attributes_record? for more info.
-    def build_new_nested_attributes_record(association_name, attributes)
-      if reject_proc = self.class.reject_new_nested_attributes_procs[association_name]
-        return if reject_proc.call(attributes)
+        if attributes['id'].blank?
+          unless reject_new_record?(association_name, attributes)
+            send(association_name).build(attributes.except(*UNASSIGNABLE_KEYS))
+          end
+        elsif existing_record = send(association_name).detect { |record| record.id.to_s == attributes['id'].to_s }
+          assign_to_or_mark_for_destruction(existing_record, attributes, allow_destroy)
+        end
       end
-      send(association_name).build(attributes) unless should_destroy_nested_attributes_record?(true, attributes)
     end
 
-    # Assigns the attributes to the record specified by +id+. Or marks it for
-    # destruction if #should_destroy_nested_attributes_record? returns +true+.
-    def assign_to_or_destroy_nested_attributes_record(association_name, id, attributes, allow_destroy)
-      record = send(association_name).detect { |record| record.id == id.to_i }
-      if should_destroy_nested_attributes_record?(allow_destroy, attributes)
+    # Updates a record with the +attributes+ or marks it for destruction if
+    # +allow_destroy+ is +true+ and has_delete_flag? returns +true+.
+    def assign_to_or_mark_for_destruction(record, attributes, allow_destroy)
+      if has_delete_flag?(attributes) && allow_destroy
         record.mark_for_destruction
       else
-        record.attributes = attributes
+        record.attributes = attributes.except(*UNASSIGNABLE_KEYS)
       end
     end
+
+    # Determines if a hash contains a truthy _delete key.
+    def has_delete_flag?(hash)
+      ConnectionAdapters::Column.value_to_boolean hash['_delete']
+    end
+
+    # Determines if a new record should be build by checking for
+    # has_delete_flag? or if a <tt>:reject_if</tt> proc exists for this
+    # association and evaluates to +true+.
+    def reject_new_record?(association_name, attributes)
+      has_delete_flag?(attributes) ||
+        self.class.reject_new_nested_attributes_procs[association_name].try(:call, attributes)
+    end
   end
-end
\ No newline at end of file
+end