Rails - Feb 2006 - Creating a new object with a passed in parent?

I have a simple object, Article, which has_one :parent of the same time. 
On my Show page for a given article there will be a "new child" button
which will pass the current :id (or the current Article itself) to the 
new form.  What is the proper way to hide a reference to this parent in 
the form so that when it is submitted back, the create method knows what 
to do with it?

I''m confused by where Rails is going to make assumptions for me.  Does 
article have a property called parent, or parent_id?  When I set it do I 
just pass in an id and Rails knows what to do with it, or do I have to 
create the object myself and then set it?  I tried something like this:

<%= hidden_field ''article'', ''parent'',
@parent %>

where @parent had been defined in the new method as
  @parent = Article.find(params[:id])

but I got undefined method `stringify_keys'' for
#<Article:0x2544068>


I''m guessing that''s because I''m trying to pass the
object through the
form rather than an id reference to it?  But if I pass around just the 
id, I can''t really use the above hidden_field reference to set 
article.parent, can I?

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

On Tuesday, February 07, 2006, at 1:49 PM, Duane wrote:
>
>I''m guessing that''s because I''m trying to pass
the object through the
>form rather than an id reference to it?  But if I pass around just the
>id, I can''t really use the above hidden_field reference to set
>article.parent, can I?
>
Sure! just do find the parent using the passed parent id like:

parent = Article.find(params[:parent_id])
....stuff goes here....
new_article.parent=parent




Mikkel Bruun

www.strongside.dk    - Football Portal(DK)
nflfeed.helenius.org - Football News(DK)
ting.minline.dk      - Buy Old Stuff!(DK)




-- 
Posted with http://DevLists.com.  Sign up and save your time!

Mikkel Bruun wrote:
> 
> parent = Article.find(params[:parent_id])
> ....stuff goes here....
> new_article.parent=parent
Thank you for the reply Mikkel, but I''m not sure I understand.  Where 
does this code go?  In my create method, which is receiving the results 
of the form submission?  That would mean I had to pass back a parameter 
called parent_id, right?  What "stuff" are you referring to? 
Here''s a
typical create method, via the scaffold generation:

 def create
    @article = Article.new(params[:article])
    if @article.save
      flash[:notice] = ''Article was successfully created.''
      redirect_to :action => ''list''
    else
      render :action => ''new''
    end
  end

I assume that I would put your code before the save command, which is 
why I''m not sure what stuff might go in between those two statements.

And where did parent_id come from?  That''s the hidden field I put in my
form, or is that an additional property that I add to the Article model?


Thank you!
Duane
> 
> 
> 
> 
> Mikkel Bruun
> 
> www.strongside.dk    - Football Portal(DK)
> nflfeed.helenius.org - Football News(DK)
> ting.minline.dk      - Buy Old Stuff!(DK)

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

> def create
>    @article = Article.new(params[:article])
>    if @article.save
>      flash[:notice] = ''Article was successfully created.''
>      redirect_to :action => ''list''
>    else
>      render :action => ''new''
>    end
>  end
>
>I assume that I would put your code before the save command, which is
>why I''m not sure what stuff might go in between those two
statements.
>
>And where did parent_id come from?  That''s the hidden field I put
in my
>form, or is that an additional property that I add to the Article model?
>
>
parent_id could/should be the name of your hidden field.

And yes, "do stuff" should occur before your save...


Mikkel Bruun

www.strongside.dk    - Football Portal(DK)
nflfeed.helenius.org - Football News(DK)
ting.minline.dk      - Buy Old Stuff!(DK)




-- 
Posted with http://DevLists.com.  Sign up and save your time!