Rails - Feb 2006 - Basic MVC in RoR question

Ok, Here''s my controller:

def create
trainingplan = Trainingplan.createplan(@params[:startdate], 
@params[:enddate], @params[:hoursperweek], @params[:programtype])

end


My model is:

class Trainingplan <ActiveRecord::Base
  def self.createplan(stardate, enddate, hoursperweek, programtype)
    stardate = startdate
    enddate = enddate
    hoursperweek = hoursperweek
    programtype = programtype
  end
end


My View is:

<%= @trainingplan.startdate %>




What I''m trying to do is add "annualhours" which is just 
hoursperweek*52.

So I add to my model:

annualhours = hoursperweek*52

However, this gives me a nil object error.

I know this is simple and I''ve read the Agile book but still
I''m not
getting it.

What exactly do I need to add to my controller or model and view in 
order to calculate and display the annualhours?

-- 
Posted via http://www.ruby-forum.com/.

On 2/5/06, Basic MVC in RoR question <webslinger143@hotmail.com>
wrote:
> Ok, Here''s my controller:
>
> def create
> trainingplan = Trainingplan.createplan(@params[:startdate],
> @params[:enddate], @params[:hoursperweek], @params[:programtype])
>
> end
>
>
> My model is:
>
> class Trainingplan <ActiveRecord::Base
>   def self.createplan(stardate, enddate, hoursperweek, programtype)
>     stardate = startdate
>     enddate = enddate
>     hoursperweek = hoursperweek
>     programtype = programtype
>   end
> end
>
>
> My View is:
>
> <%= @trainingplan.startdate %>
>
>
>
>
> What I''m trying to do is add "annualhours" which is just
> hoursperweek*52.
>
> So I add to my model:
>
> annualhours = hoursperweek*52
>
> However, this gives me a nil object error.
>
> I know this is simple and I''ve read the Agile book but still
I''m not
> getting it.
>
> What exactly do I need to add to my controller or model and view in
> order to calculate and display the annualhours?
Er, annualhours is probably a local variable in the model, so it goes
away at the end of the method call.  That''s why you don''t see
it in
the view.

What you want is a new method called annualhours (although it should
be called annual_hours).

So:

class TrainingPlan < AR
  def annual_hours
    self.hoursperweek * 52
  end
end

> Er, annualhours is probably a local variable in the model, so it goes
> away at the end of the method call.  That''s why you don''t
see it in
> the view.
> 
> What you want is a new method called annualhours (although it should
> be called annual_hours).
> 
> So:
> 
> class TrainingPlan < AR
>   def annual_hours
>     self.hoursperweek * 52
>   end
> end
annualhours is part of the model as it is a column in the database. 
Therefore I assumed it would be part of Trainingplan.  I don''t 
understand why it would be local to the model and not available in the 
view? I was under the impression that instance variables like 
@annualhours were local to the model, controller, or view and variables 
that were part of the model were accessible in the view.  So if I have 
annualhours defined as a part of the trainingplan table, shouldn''t I be
able in the model to do:

annualhours = hoursperweek*52

and in the view do:

@trainingplan.annualhours

This however doesn''t work.


-- 
Posted via http://www.ruby-forum.com/.

Can you post more complete code from the controller, model, and view? It
sounds like it should work more or less, so it could be some subtle problem
in your code. I''ve noticed, for instance, a few typos above and
I''m not sure
if that is your actual code or you re-typed it.

- byron

On 2/5/06, Basic MVC in RoR question <webslinger143@hotmail.com>
wrote:
>
> > Er, annualhours is probably a local variable in the model, so it goes
> > away at the end of the method call.  That''s why you
don''t see it in
> > the view.
> >
> > What you want is a new method called annualhours (although it should
> > be called annual_hours).
> >
> > So:
> >
> > class TrainingPlan < AR
> >   def annual_hours
> >     self.hoursperweek * 52
> >   end
> > end
>
> annualhours is part of the model as it is a column in the database.
> Therefore I assumed it would be part of Trainingplan.  I don''t
> understand why it would be local to the model and not available in the
> view? I was under the impression that instance variables like
> @annualhours were local to the model, controller, or view and variables
> that were part of the model were accessible in the view.  So if I have
> annualhours defined as a part of the trainingplan table, shouldn''t
I be
> able in the model to do:
>
> annualhours = hoursperweek*52
>
> and in the view do:
>
> @trainingplan.annualhours
>
> This however doesn''t work.
>
>
> --
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>


--
Byron
http://byron.saltysiak.com
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Basic MVC in RoR question wrote:
> annualhours is part of the model as it is a column in the database. 
> Therefore I assumed it would be part of Trainingplan.  I don''t 
> understand why it would be local to the model and not available in the 
> view? I was under the impression that instance variables like 
> @annualhours were local to the model, controller, or view and variables 
> that were part of the model were accessible in the view.  So if I have 
> annualhours defined as a part of the trainingplan table, shouldn''t
I be
> able in the model to do:
> 
> annualhours = hoursperweek*52
> 
> and in the view do:
> 
> @trainingplan.annualhours
> 
> This however doesn''t work.
If annualhours is a column in the table, I believe you need to do 
self.annualhours within the model class in order to set or access its value.
> class Trainingplan <ActiveRecord::Base
>   def self.createplan(stardate, enddate, hoursperweek, programtype)
>     stardate = startdate
>     enddate = enddate
>     hoursperweek = hoursperweek
>     programtype = programtype
>   end
> end
Also, what you''re doing here isn''t actually creating a row in
the database. At
no time do you create a new TrainingPlan class, and you don''t make a
call to
that objects save method. So I think you need to go back to your controller:
> def create
> trainingplan = Trainingplan.createplan(@params[:startdate], 
> @params[:enddate], @params[:hoursperweek], @params[:programtype])
> end

And change this code to something more like this:

def create
   trainingplan = TrainingPlan.create (
     :stardate => @params[:startdate],
     :enddate => @params[:enddate],
     :hoursperweek => @params[:hoursperweek],
     :annualhours => @params[:hoursperweek].to_i * 52,
     :programtype => @params[:programtype])
end

-Brian