Question

The ActiveResource::Base#update_attributes method calls a ActiveResource::Base#load method which is defined in activeresource-3.1.3/lib/active_resource/base.rb (line 1255). I am trying to call that load method, rather than simply using update_attributes so that the object is not saved immediately.

1. I tested this with a completely new rails application. I scaffolded a simple object:

   rails scaffold obj property1:string
   

2. Then in the rails console:

   irb(main):001:0> obj=Obj.new
   irb(main):002:0> obj.load(:property1=>"data")
   TypeError: can't convert Hash into String
   from .../activesupport-3.1.3/lib/active_support/dependencies.rb:234:in `load'
   from .../activesupport-3.1.3/lib/active_support/dependencies.rb:234:in `load'
   from .../activesupport-3.1.3/lib/active_support/dependencies.rb:223:in `load_dependency'
   from .../activesupport-3.1.3/lib/active_support/dependencies.rb:640:in `new_constants_in'
   from .../activesupport-3.1.3/lib/active_support/dependencies.rb:223:in `load_dependency'
   from .../activesupport-3.1.3/lib/active_support/dependencies.rb:234:in `load'
   from (irb):2
   

I see that activesupport-3.1.3/lib/active_support/dependencies.rb applies its Loadable module to Object, giving every object a load method for loading files, but I can’t figure out why it overrides the ActiveResource::Base#load method and not the other way around.

I am using Rails 3.1.3 and friends.

Update:

I think I’ve answered my own question. I’ve been trying to use ActiveResource methods on ActiveRecord objects. I know that my Rails model classes are descendants of ActiveRecord::Base, but somehow when I was trying to find the code for ActiveRecord::Base#update_attributes I found the code for ActiveResource::Base#update_attributes instead, which looks like this:

def update_attributes(attributes)
  load(attributes, false) && save
end

So I’ve been trying to call the load method, which exists for my objects only as provided by activesupport. If I had only looked at ActiveRecord::Base#update_attributes which is

def update_attributes(attributes, options = {})
  # The following transaction covers any possible database side-effects of the
  # attributes assignment. For example, setting the IDs of a child collection.
  with_transaction_returning_status do
    self.assign_attributes(attributes, options)
    save
  end
end

I would have seen that the assign_attributes method is what I needed.

Answer 1

Instead of doing that, you could use .attributes

obj = Obj.new
obj.attributes = { :property1 => "data" }

The instance has new attributes, but has not been saved.

Read the Docs for more info.