ActiveRecord is being converted to Hash unexpectedly

I am running into a very odd problem. I have an ActiveRecord called
Objective with a public create method. When this method is called in
a controller the return value is a Hash instead of Objective. When I
test the method in Rspec for the model it returns as Objective.

Does anyone have an idea about why the return type would be different
and if so how to fix it so it always returns Objective?

Code:

class Objective < ActiveRecord::Base
  belongs_to :user
  has_many :next_actions, :order => 'id DESC', :conditions =>
{:completed => false}
  has_many :action_items, :order => 'position'
  has_many :progress_updates

  serialize :freq_value

validates_presence_of :name, :due_date, :completion, :pr_u_frequency_id
  validates_numericality_of :completion, :only_integer =>
true, :greater_than_or_equal_to => 0, :less_than_or_equal_to => 100

def self.create(attributes, user_id)
    #create new record with user_id correctly set
    attributes.delete :freq_options #deletes this unused key
    obj = self.new(attributes)
    obj.user_id = user_id
    obj.save ? obj : nil

  end

end

class ObjectivesController < ApplicationController
  before_filter :require_user

  layout false

  def create
    objective = Objective.create(params[:objective], current_user.id)
    Rails.logger.info("****objective.class = #{objective.class}****")
  end
end

I should mention that the Hash does contain the Objective's data. the
reason it is important that Objective is returned instead of Hash is
because I want to be able to call methods on it.

hi,drewB
  first,I don't agree about the code of create method,use another
method name seems better.
  second,you mentioned that "objective.class" will return Hash? It's
impossible,Objective#create return a instance of Objective or nil~~
  finally,show out your code about Rspec,please~

Thanks for your reply.

hi,drewB
first,I don't agree about the code of create method,use another
method name seems better.

Why don't you agree?

second,you mentioned that "objective.class" will return Hash? It's
impossible,Objective#create return a instance of Objective or nil~~

I agree it is very strange but the log file clearly shows that it is
returning a Hash (so are the error messages I get when I try to call a
method).

finally,show out your code about Rspec,please~

#I am using machinist. Objective.plan returns a hash with values I
specify elsewhere
it "should return objective when create called" do
    obj = Objective.create(Objective.plan, 5)
    obj.class.to_s.should == "Objective"
end

It is overwritten because the objective requires a user_id which comes
from a different place than the other attributes. I could simply use
create and add more code at the controller level but I prefer to push
that down to the model.

Marnen Laibow-Koser had pointed out the reason.
put more code at the model is best practice,but in this
situation,ActiveRecord already gives you a brief solution~

your problem seems so strange....I will write codes to test it...

maybe you should use another method name and try again~~

Then create a method with a different name -- say, create_with_user_id
-- or use a before_create callback to set the user_id. Don't override
create.

or in this case, using associations and writing
some_user.objectives.create(...) would be even nicer. Would still be
interesting to find exactly what is going on.

Fred

> Then create a method with a different name -- say, create_with_user_id
> -- or use a before_create callback to set the user_id. Don't override
> create.

or in this case, using associations and writing
some_user.objectives.create(...) would be even nicer.

I see where you are coming from.

Would still be interesting to find exactly what is going on.

Yes, very much so!

Try this:

class ObjectivesController < ApplicationController
  before_filter :require_user
  layout false
  def create
    objective = current_user.objectives.create(params[:objective])
  end
end

And as others have said, don't overwrite AR class methods like
'create', otherwise you will enter a world of pain.

Also, you are deleting a param called 'freq_options', if the model
does not need it then it shouldn't be in the hash. If the controller
needs it, then pass it as params[:freq_options] rather than params
[:objective][:freq_options]. If it's not used there, then why pass it
at all?

-- W

Wes wrote:

Try this:

class ObjectivesController < ApplicationController
  before_filter :require_user
  layout false
  def create
    objective = current_user.objectives.create(params[:objective])
  end
end

No! Create shouldn't be a controller method.

And as others have said, don't overwrite

over*ride*

AR class methods like
'create', otherwise you will enter a world of pain.

Yeah. If you must override, it's probably best to do something like

def create(attributes, user_id)
  super(attributes.merge :user_id => user_id)
end

but even this is kind of bad.

Also, you are deleting a param called 'freq_options', if the model
does not need it then it shouldn't be in the hash. If the controller
needs it, then pass it as params[:freq_options] rather than params
[:objective][:freq_options]. If it's not used there, then why pass it
at all?

Good catch!

-- W

Best,

Wes wrote:
> Try this:

> class ObjectivesController < ApplicationController
> before_filter :require_user
> layout false
> def create
> objective = current_user.objectives.create(params[:objective])
> end
> end

No! Create shouldn't be a controller method.

Why not?

> And as others have said, don't overwrite

over*ride*

> AR class methods like
> 'create', otherwise you will enter a world of pain.

Thanks for the good practice tip.

Yeah. If you must override, it's probably best to do something like

def create(attributes, user_id)
super(attributes.merge :user_id => user_id)
end

but even this is kind of bad.

> Also, you are deleting a param called 'freq_options', if the model
> does not need it then it shouldn't be in the hash. If the controller
> needs it, then pass it as params[:freq_options] rather than params
> [:objective][:freq_options]. If it's not used there, then why pass it
> at all?

Good catch!

It will eventually be used, just not yet.

Wes wrote:
> Try this:

> class ObjectivesController < ApplicationController
> before_filter :require_user
> layout false
> def create
> objective = current_user.objectives.create(params[:objective])
> end
> end

No! Create shouldn't be a controller method.

Huh? It's rails convention. A restful controller has 6 actions (index,
show, create, edit, update, destroy).

> And as others have said, don't overwrite

over*ride*

Wow, why so pedantic? The intent was clear. Did I kick your puppy or
something?

> AR class methods like
> 'create', otherwise you will enter a world of pain.

Yeah. If you must override, it's probably best to do something like

def create(attributes, user_id)
super(attributes.merge :user_id => user_id)
end

but even this is kind of bad.

That's a really bad example as the additional parameter is handled via
an association. Besides, if an attribute is not in the request
attributes hash, it's much easier to just add it in the controller,
since that's what you're already doing in a backwards sort of way.
Ex: Foo.create(params[:foo].merge(:my_var => 'bar')) vs. Foo.create
(params[:foo], 'bar') + an ugly overridden method in the class

-- W

> Wes wrote:
> > Try this:

> > class ObjectivesController < ApplicationController
> > before_filter :require_user
> > layout false
> > def create
> > objective = current_user.objectives.create(params[:objective])
> > end
> > end

> No! Create shouldn't be a controller method.

Why not?

There's no reason not to. In fact it's a Rails convention to do so.

> > And as others have said, don't overwrite

> over*ride*

> > AR class methods like
> > 'create', otherwise you will enter a world of pain.

Thanks for the good practice tip.

> Yeah. If you must override, it's probably best to do something like

> def create(attributes, user_id)
> super(attributes.merge :user_id => user_id)
> end

> but even this is kind of bad.

> > Also, you are deleting a param called 'freq_options', if the model
> > does not need it then it shouldn't be in the hash. If the controller
> > needs it, then pass it as params[:freq_options] rather than params
> > [:objective][:freq_options]. If it's not used there, then why pass it
> > at all?

> Good catch!

It will eventually be used, just not yet.

Ok, if you intend to use it later, then you can just specify an
accessor in your model, that way you can pass it in without error.

class Objective < ActiveRecord::Base
  attr_accessor :freq_options
end

Then later if you add this as a db attribute, you can remove the
accessor. Otherwise you may want to do some manipulation of other data
in the model based on the value of this accessor (via callbacks).

-- W

Thanks everyone for the help. I didn't end up figuring out what was
causing the problem but changing the code to current_user.Objective...
fixed the problem and makes a lot more sense.

I hope not too many puppies were hurt during this exchange :).