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Diffstat (limited to 'activerecord/lib/active_record/observer.rb')
| -rw-r--r-- | activerecord/lib/active_record/observer.rb | 126 |
1 files changed, 0 insertions, 126 deletions
diff --git a/activerecord/lib/active_record/observer.rb b/activerecord/lib/active_record/observer.rb deleted file mode 100644 index 6b2f6f98a5..0000000000 --- a/activerecord/lib/active_record/observer.rb +++ /dev/null @@ -1,126 +0,0 @@ - -module ActiveRecord - # = Active Record Observer - # - # Observer classes respond to life cycle callbacks to implement trigger-like - # behavior outside the original class. This is a great way to reduce the - # clutter that normally comes when the model class is burdened with - # functionality that doesn't pertain to the core responsibility of the - # class. Example: - # - # class CommentObserver < ActiveRecord::Observer - # def after_save(comment) - # Notifications.comment("admin@do.com", "New comment was posted", comment).deliver - # end - # end - # - # This Observer sends an email when a Comment#save is finished. - # - # class ContactObserver < ActiveRecord::Observer - # def after_create(contact) - # contact.logger.info('New contact added!') - # end - # - # def after_destroy(contact) - # contact.logger.warn("Contact with an id of #{contact.id} was destroyed!") - # end - # end - # - # This Observer uses logger to log when specific callbacks are triggered. - # - # == Observing a class that can't be inferred - # - # Observers will by default be mapped to the class with which they share a name. So CommentObserver will - # be tied to observing Comment, ProductManagerObserver to ProductManager, and so on. If you want to name your observer - # differently than the class you're interested in observing, you can use the Observer.observe class method which takes - # either the concrete class (Product) or a symbol for that class (:product): - # - # class AuditObserver < ActiveRecord::Observer - # observe :account - # - # def after_update(account) - # AuditTrail.new(account, "UPDATED") - # end - # end - # - # If the audit observer needs to watch more than one kind of object, this can be specified with multiple arguments: - # - # class AuditObserver < ActiveRecord::Observer - # observe :account, :balance - # - # def after_update(record) - # AuditTrail.new(record, "UPDATED") - # end - # end - # - # The AuditObserver will now act on both updates to Account and Balance by treating them both as records. - # - # == Available callback methods - # - # The observer can implement callback methods for each of the methods described in the Callbacks module. - # - # == Storing Observers in Rails - # - # If you're using Active Record within Rails, observer classes are usually stored in app/models with the - # naming convention of app/models/audit_observer.rb. - # - # == Configuration - # - # In order to activate an observer, list it in the <tt>config.active_record.observers</tt> configuration - # setting in your <tt>config/application.rb</tt> file. - # - # config.active_record.observers = :comment_observer, :signup_observer - # - # Observers will not be invoked unless you define these in your application configuration. - # - # If you are using Active Record outside Rails, activate the observers explicitly in a configuration or - # environment file: - # - # ActiveRecord::Base.add_observer CommentObserver.instance - # ActiveRecord::Base.add_observer SignupObserver.instance - # - # == Loading - # - # Observers register themselves in the model class they observe, since it is the class that - # notifies them of events when they occur. As a side-effect, when an observer is loaded its - # corresponding model class is loaded. - # - # Up to (and including) Rails 2.0.2 observers were instantiated between plugins and - # application initializers. Now observers are loaded after application initializers, - # so observed models can make use of extensions. - # - # If by any chance you are using observed models in the initialization you can still - # load their observers by calling <tt>ModelObserver.instance</tt> before. Observers are - # singletons and that call instantiates and registers them. - # - class Observer < ActiveModel::Observer - - protected - - def observed_classes - klasses = super - klasses + klasses.map { |klass| klass.descendants }.flatten - end - - def add_observer!(klass) - super - define_callbacks klass - end - - def define_callbacks(klass) - observer = self - observer_name = observer.class.name.underscore.gsub('/', '__') - - ActiveRecord::Callbacks::CALLBACKS.each do |callback| - next unless respond_to?(callback) - callback_meth = :"_notify_#{observer_name}_for_#{callback}" - unless klass.respond_to?(callback_meth) - klass.send(:define_method, callback_meth) do |&block| - observer.update(callback, self, &block) - end - klass.send(callback, callback_meth) - end - end - end - end -end |