+++ /dev/null
-module ActiveRecord
- # AutosaveAssociation is a module that takes care of automatically saving
- # your associations when the parent is saved. In addition to saving, it
- # also destroys any associations that were marked for destruction.
- # (See mark_for_destruction and marked_for_destruction?)
- #
- # Saving of the parent, its associations, and the destruction of marked
- # associations, all happen inside 1 transaction. This should never leave the
- # database in an inconsistent state after, for instance, mass assigning
- # attributes and saving them.
- #
- # If validations for any of the associations fail, their error messages will
- # be applied to the parent.
- #
- # Note that it also means that associations marked for destruction won't
- # be destroyed directly. They will however still be marked for destruction.
- #
- # === One-to-one Example
- #
- # Consider a Post model with one Author:
- #
- # class Post
- # has_one :author, :autosave => true
- # end
- #
- # Saving changes to the parent and its associated model can now be performed
- # automatically _and_ atomically:
- #
- # post = Post.find(1)
- # post.title # => "The current global position of migrating ducks"
- # post.author.name # => "alloy"
- #
- # post.title = "On the migration of ducks"
- # post.author.name = "Eloy Duran"
- #
- # post.save
- # post.reload
- # post.title # => "On the migration of ducks"
- # post.author.name # => "Eloy Duran"
- #
- # Destroying an associated model, as part of the parent's save action, is as
- # simple as marking it for destruction:
- #
- # post.author.mark_for_destruction
- # post.author.marked_for_destruction? # => true
- #
- # Note that the model is _not_ yet removed from the database:
- # id = post.author.id
- # Author.find_by_id(id).nil? # => false
- #
- # post.save
- # post.reload.author # => nil
- #
- # Now it _is_ removed from the database:
- # Author.find_by_id(id).nil? # => true
- #
- # === One-to-many Example
- #
- # Consider a Post model with many Comments:
- #
- # class Post
- # has_many :comments, :autosave => true
- # end
- #
- # Saving changes to the parent and its associated model can now be performed
- # automatically _and_ atomically:
- #
- # post = Post.find(1)
- # post.title # => "The current global position of migrating ducks"
- # post.comments.first.body # => "Wow, awesome info thanks!"
- # post.comments.last.body # => "Actually, your article should be named differently."
- #
- # post.title = "On the migration of ducks"
- # post.comments.last.body = "Actually, your article should be named differently. [UPDATED]: You are right, thanks."
- #
- # post.save
- # post.reload
- # post.title # => "On the migration of ducks"
- # post.comments.last.body # => "Actually, your article should be named differently. [UPDATED]: You are right, thanks."
- #
- # Destroying one of the associated models members, as part of the parent's
- # save action, is as simple as marking it for destruction:
- #
- # post.comments.last.mark_for_destruction
- # post.comments.last.marked_for_destruction? # => true
- # post.comments.length # => 2
- #
- # Note that the model is _not_ yet removed from the database:
- # id = post.comments.last.id
- # Comment.find_by_id(id).nil? # => false
- #
- # post.save
- # post.reload.comments.length # => 1
- #
- # Now it _is_ removed from the database:
- # Comment.find_by_id(id).nil? # => true
- #
- # === Validation
- #
- # Validation is performed on the parent as usual, but also on all autosave
- # enabled associations. If any of the associations fail validation, its
- # error messages will be applied on the parents errors object and validation
- # of the parent will fail.
- #
- # Consider a Post model with Author which validates the presence of its name
- # attribute:
- #
- # class Post
- # has_one :author, :autosave => true
- # end
- #
- # class Author
- # validates_presence_of :name
- # end
- #
- # post = Post.find(1)
- # post.author.name = ''
- # post.save # => false
- # post.errors # => #<ActiveRecord::Errors:0x174498c @errors={"author_name"=>["can't be blank"]}, @base=#<Post ...>>
- #
- # No validations will be performed on the associated models when validations
- # are skipped for the parent:
- #
- # post = Post.find(1)
- # post.author.name = ''
- # post.save(false) # => true
- module AutosaveAssociation
- ASSOCIATION_TYPES = %w{ has_one belongs_to has_many has_and_belongs_to_many }
-
- def self.included(base)
- base.class_eval do
- base.extend(ClassMethods)
- alias_method_chain :reload, :autosave_associations
-
- ASSOCIATION_TYPES.each do |type|
- base.send("valid_keys_for_#{type}_association") << :autosave
- end
- end
- end
-
- module ClassMethods
- private
-
- # def belongs_to(name, options = {})
- # super
- # add_autosave_association_callbacks(reflect_on_association(name))
- # end
- ASSOCIATION_TYPES.each do |type|
- module_eval %{
- def #{type}(name, options = {})
- super
- add_autosave_association_callbacks(reflect_on_association(name))
- end
- }
- end
-
- # Adds a validate and save callback for the association as specified by
- # the +reflection+.
- def add_autosave_association_callbacks(reflection)
- save_method = "autosave_associated_records_for_#{reflection.name}"
- validation_method = "validate_associated_records_for_#{reflection.name}"
- validate validation_method
-
- case reflection.macro
- when :has_many, :has_and_belongs_to_many
- before_save :before_save_collection_association
-
- define_method(save_method) { save_collection_association(reflection) }
- # Doesn't use after_save as that would save associations added in after_create/after_update twice
- after_create save_method
- after_update save_method
-
- define_method(validation_method) { validate_collection_association(reflection) }
- else
- case reflection.macro
- when :has_one
- define_method(save_method) { save_has_one_association(reflection) }
- after_save save_method
- when :belongs_to
- define_method(save_method) { save_belongs_to_association(reflection) }
- before_save save_method
- end
- define_method(validation_method) { validate_single_association(reflection) }
- end
- end
- end
-
- # Reloads the attributes of the object as usual and removes a mark for destruction.
- def reload_with_autosave_associations(options = nil)
- @marked_for_destruction = false
- reload_without_autosave_associations(options)
- end
-
- # Marks this record to be destroyed as part of the parents save transaction.
- # This does _not_ actually destroy the record yet, rather it will be destroyed when <tt>parent.save</tt> is called.
- #
- # Only useful if the <tt>:autosave</tt> option on the parent is enabled for this associated model.
- def mark_for_destruction
- @marked_for_destruction = true
- end
-
- # Returns whether or not this record will be destroyed as part of the parents save transaction.
- #
- # Only useful if the <tt>:autosave</tt> option on the parent is enabled for this associated model.
- def marked_for_destruction?
- @marked_for_destruction
- end
-
- private
-
- # Returns the record for an association collection that should be validated
- # or saved. If +autosave+ is +false+ only new records will be returned,
- # unless the parent is/was a new record itself.
- def associated_records_to_validate_or_save(association, new_record, autosave)
- if new_record
- association
- elsif association.loaded?
- autosave ? association : association.select { |record| record.new_record? }
- else
- autosave ? association.target : association.target.select { |record| record.new_record? }
- end
- end
-
- # Validate the association if <tt>:validate</tt> or <tt>:autosave</tt> is
- # turned on for the association specified by +reflection+.
- def validate_single_association(reflection)
- if reflection.options[:validate] == true || reflection.options[:autosave] == true
- if (association = association_instance_get(reflection.name)) && !association.target.nil?
- association_valid?(reflection, association)
- end
- end
- end
-
- # Validate the associated records if <tt>:validate</tt> or
- # <tt>:autosave</tt> is turned on for the association specified by
- # +reflection+.
- def validate_collection_association(reflection)
- if reflection.options[:validate] != false && association = association_instance_get(reflection.name)
- if records = associated_records_to_validate_or_save(association, new_record?, reflection.options[:autosave])
- records.each { |record| association_valid?(reflection, record) }
- end
- end
- end
-
- # Returns whether or not the association is valid and applies any errors to
- # the parent, <tt>self</tt>, if it wasn't. Skips any <tt>:autosave</tt>
- # enabled records if they're marked_for_destruction?.
- def association_valid?(reflection, association)
- unless valid = association.valid?
- if reflection.options[:autosave]
- unless association.marked_for_destruction?
- association.errors.each do |attribute, message|
- attribute = "#{reflection.name}_#{attribute}"
- errors.add(attribute, message) unless errors.on(attribute)
- end
- end
- else
- errors.add(reflection.name)
- end
- end
- valid
- end
-
- # Is used as a before_save callback to check while saving a collection
- # association whether or not the parent was a new record before saving.
- def before_save_collection_association
- @new_record_before_save = new_record?
- true
- end
-
- # Saves any new associated records, or all loaded autosave associations if
- # <tt>:autosave</tt> is enabled on the association.
- #
- # In addition, it destroys all children that were marked for destruction
- # with mark_for_destruction.
- #
- # This all happens inside a transaction, _if_ the Transactions module is included into
- # ActiveRecord::Base after the AutosaveAssociation module, which it does by default.
- def save_collection_association(reflection)
- if association = association_instance_get(reflection.name)
- autosave = reflection.options[:autosave]
-
- if records = associated_records_to_validate_or_save(association, @new_record_before_save, autosave)
- records.each do |record|
- if autosave && record.marked_for_destruction?
- association.destroy(record)
- elsif @new_record_before_save || record.new_record?
- if autosave
- association.send(:insert_record, record, false, false)
- else
- association.send(:insert_record, record)
- end
- elsif autosave
- record.save(false)
- end
- end
- end
-
- # reconstruct the SQL queries now that we know the owner's id
- association.send(:construct_sql) if association.respond_to?(:construct_sql)
- end
- end
-
- # Saves the associated record if it's new or <tt>:autosave</tt> is enabled
- # on the association.
- #
- # In addition, it will destroy the association if it was marked for
- # destruction with mark_for_destruction.
- #
- # This all happens inside a transaction, _if_ the Transactions module is included into
- # ActiveRecord::Base after the AutosaveAssociation module, which it does by default.
- def save_has_one_association(reflection)
- if (association = association_instance_get(reflection.name)) && !association.target.nil?
- if reflection.options[:autosave] && association.marked_for_destruction?
- association.destroy
- elsif new_record? || association.new_record? || association[reflection.primary_key_name] != id || reflection.options[:autosave]
- association[reflection.primary_key_name] = id
- association.save(false)
- end
- end
- end
-
- # Saves the associated record if it's new or <tt>:autosave</tt> is enabled
- # on the association.
- #
- # In addition, it will destroy the association if it was marked for
- # destruction with mark_for_destruction.
- #
- # This all happens inside a transaction, _if_ the Transactions module is included into
- # ActiveRecord::Base after the AutosaveAssociation module, which it does by default.
- def save_belongs_to_association(reflection)
- if association = association_instance_get(reflection.name)
- if reflection.options[:autosave] && association.marked_for_destruction?
- association.destroy
- else
- association.save(false) if association.new_record? || reflection.options[:autosave]
-
- if association.updated?
- self[reflection.primary_key_name] = association.id
- # TODO: Removing this code doesn't seem to matter…
- if reflection.options[:polymorphic]
- self[reflection.options[:foreign_type]] = association.class.base_class.name.to_s
- end
- end
- end
- end
- end
- end
-end
\ No newline at end of file
projects / feedcatcher.git / blobdiff