module ActiveFedora::AutosaveAssociation
Active Fedora
Autosave Association¶ ↑
AutosaveAssociation
is a module that takes care of automatically saving associacted records when their parent is saved. In addition to saving, it also destroys any associated records 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 a transaction. This should never leave the database in an inconsistent state.
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.
Note that :autosave => false
is not same as not declaring :autosave
. When the :autosave
option is not present new associations are saved.
One-to-many Example¶ ↑
When :autosave
is not declared new children are saved when their parent is saved:
class Post has_many :comments # :autosave option is no declared end post = Post.new(:title => 'ruby rocks') post.comments.build(:body => 'hello world') post.save # => saves both post and comment post = Post.create(:title => 'ruby rocks') post.comments.build(:body => 'hello world') post.save # => saves both post and comment post = Post.create(:title => 'ruby rocks') post.comments.create(:body => 'hello world') post.save # => saves both post and comment
When :autosave
is true all children is saved, no matter whether they are new records:
class Post has_many :comments, :autosave => true end post = Post.create(:title => 'ruby rocks') post.comments.create(:body => 'hello world') post.comments[0].body = 'hi everyone' post.save # => saves both post and comment, with 'hi everyone' as body
Destroying one of the associated models 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¶ ↑
Children records are validated unless :validate
is false
.
Constants
- ASSOCIATION_TYPES
Public Instance Methods
Returns whether or not this record has been changed in any way (including whether any of its nested autosave associations are likewise changed)
# File lib/active_fedora/autosave_association.rb, line 191 def changed_for_autosave? new_record? || changed? || marked_for_destruction? || nested_records_changed_for_autosave? end
Returns the association for the parent being destroyed.
Used to avoid updating the counter cache unnecessarily.
# File lib/active_fedora/autosave_association.rb, line 185 def destroyed_by_association @destroyed_by_association end
Records the association that is being destroyed and destroying this record in the process.
# File lib/active_fedora/autosave_association.rb, line 178 def destroyed_by_association=(reflection) @destroyed_by_association = reflection end
Marks this record to be destroyed as part of the parents save transaction. This does not actually destroy the record instantly, rather child record will be destroyed when parent.save
is called.
Only useful if the :autosave
option on the parent is enabled for this associated model.
# File lib/active_fedora/autosave_association.rb, line 165 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 :autosave
option on the parent is enabled for this associated model.
# File lib/active_fedora/autosave_association.rb, line 172 def marked_for_destruction? @marked_for_destruction end
Reloads the attributes of the object as usual and clears marked_for_destruction
flag.
# File lib/active_fedora/autosave_association.rb, line 154 def reload @marked_for_destruction = false @destroyed_by_association = nil super end
Private Instance Methods
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.
# File lib/active_fedora/autosave_association.rb, line 200 def associated_records_to_validate_or_save(association, new_record, autosave) if new_record association&.target elsif autosave association.target.find_all(&:changed_for_autosave?) else association.target.find_all(&:new_record?) end end
Returns whether or not the association is valid and applies any errors to the parent, self
, if it wasn’t. Skips any :autosave
enabled records if they’re marked_for_destruction? or destroyed.
# File lib/active_fedora/autosave_association.rb, line 241 def association_valid?(reflection, record) return true if record.destroyed? || record.marked_for_destruction? unless valid = record.valid? if reflection.options[:autosave] record.errors.messages.each do |attribute, messages| attribute = "#{reflection.name}.#{attribute}" messages.map { |message| errors.add(attribute, message: message) } 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.
# File lib/active_fedora/autosave_association.rb, line 259 def before_save_collection_association @new_record_before_save = new_record? true end
go through nested autosave associations that are loaded in memory (without loading any new ones), and return true if is changed for autosave
# File lib/active_fedora/autosave_association.rb, line 212 def nested_records_changed_for_autosave? self.class.reflect_on_all_autosave_associations.any? do |reflection| association = association_instance_get(reflection.name) association && Array(association.target).any?(&:changed_for_autosave?) end end
Saves the associated record if it’s new or :autosave
is enabled.
In addition, it will destroy the association if it was marked for destruction.
# File lib/active_fedora/autosave_association.rb, line 306 def save_belongs_to_association(reflection) association = association_instance_get(reflection.name) record = association&.load_target if record && !record.destroyed? autosave = reflection.options[:autosave] if autosave && record.marked_for_destruction? record.destroy elsif autosave != false saved = record.save(validate: !autosave) if record.new_record? || (autosave && record.changed_for_autosave?) if association.updated? self[reflection.foreign_key] = record.id association.loaded! end saved if autosave end end end
Saves any new associated records, or all loaded autosave associations if :autosave
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 ActiveFedora::Base
after the AutosaveAssociation
module, which it does by default.
# File lib/active_fedora/autosave_association.rb, line 272 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| next if record.destroyed? saved = true if autosave && record.marked_for_destruction? association.proxy.destroy(record) elsif autosave != false && (@new_record_before_save || record.new_record?) if autosave saved = association.insert_record(record, false) else association.insert_record(record) end elsif autosave saved = record.save(validate: false) end raise ActiveFedora::Rollback unless saved end end # reconstruct the scope now that we know the owner's id association.send(:reset_scope) if association.respond_to?(:reset_scope) end end
Validate the associated records if :validate
or :autosave
is turned on for the association specified by reflection
.
# File lib/active_fedora/autosave_association.rb, line 230 def validate_collection_association(reflection) if 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
Validate the association if :validate
or :autosave
is turned on for the association.
# File lib/active_fedora/autosave_association.rb, line 221 def validate_single_association(reflection) association = association_instance_get(reflection.name) record = association&.target association_valid?(reflection, record) if record end