How to find documentation for ActiveRecord :: Base.update?

Question

What is the process of finding documentation for a method in the Ruby / Rails api http://api.rubyonrails.org/ .

Take the ActiveRecord::Base.update method as an example. It is used in one of the railscasts.

• In the api doc for the class there is no mention of updating http://api.rubyonrails.org/classes/ActiveRecord/Base.html
• There's nothing about the update method in the source code for Base https://github.com/rails/rails/blob/0065f378262dc3f47880ce6211c7474bc7d11f0b/activerecord/lib/active_record/base.rb
• In fact, I cannot even find this method in any classes included in ActiveRecord::Base .

I suspect this method is in ActiveRecord :: Relation. However, I am not sure.

I am new to Ruby / Rails, and I come from the Java world, where I usually expect to see all methods (inherited) in javadoc for a class. What is the most efficient way to find relevant documentation for mixed / inherited methods in the case of Ruby / Rails?

Thanks in advance!

Answer 1

You probably can't find good documentation on ActiveRecord::Base#update , because the method was deprecated with Rails version 2.3.8, according to the APIdock. .

The reason you can still use it is because it has been ported to ActiveRecord::Relation , which is visible in rails/activerecord/lib/active_record/relation.rb .

rails/activerecord/lib/active_record.rb contains all the autoload for ActiveRecord , which includes :Relation .

The documentation for ActiveRecord::Relation#update as follows:

Updates the object (or several objects) and stores it in the database if the checks pass. The resulting object is returned whether the object was successfully stored in the database or not.

==== Parameters

• + id + - This should be an identifier or an array of identifiers that need to be updated.
• + attributes + - This should be an attribute hash or an array of hashes.

==== Examples

 # Updates one record Person.update(15, :user_name => 'Samuel', :group => 'expert') # Updates multiple records people = { 1 => { "first_name" => "David" }, 2 => { "first_name" => "Jeremy" } } Person.update(people.keys, people.values) 

EDIT. To answer your initial question, in most cases a search on api.rubyonrails.org is enough to find the information you are looking for since if the information is updated.

For more information on the API, use apidock.com/rails . Doing a search there for the “update” actually shows both versions ( ::Base and ::Relation ) and gives you detailed information about each and which version of Rails each is used for.

Answer 2

ActiveRecord :: Base.update no longer exists, as you can see here: http://apidock.com/rails/ActiveRecord/Base/update/class , this is ActiveRecord :: Relation now as here: http://apidock.com / rails / ActiveRecord / Relation / update