Rails - Feb 2006 - Obtaining the ID of a newly saved model object

Hi,

I''m struggling with this and I''m not sure if it is obvious or
dumb (or both).

I have a basic create method like so:

def creatematerial
  @material = Material.new(params[:material])
  if @material.save
    flash[:notice] = "Material successfully created."
  end

Ok so far, but now I want to retrieve that object that was just saved so that it
can be used in the view. Something like...

  @newmaterial = Material.find(@material.id)

is what I was thinking, but that doesn''t work as @material still has no
id.

The method finishes with a rendering of a table (this is an AJAX called method)

  render_partial ''listtable'', :layout => false
end

I want to grab the newly created object so I can hightlight and display it in
the view, but I don''t know how to retrieve it again!

Any and all ideas are most appreciated.

Chris.

Quoting Christopher.Preston@csiro.au:
>
>   @newmaterial = Material.find(@material.id)
>
> is what I was thinking, but that doesn''t work as @material still
has no id.
Doesn''t it work if you do a @material.reload ?

Frederick Ros aka Sleeper -- sleeper@jabber.fr

Are you sure your object has been correctly saved in your database ? I 
think the save() method should populate the id instance variable.

Thomas.

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

Chris,

Rails saves your Model instance and adds the resulting id to its  
attributes.  And you still "have" the object so there is no need to  
refind it.

Something like this should work:

def creatematerial
	@material = Material.new(params[:material])
	if @material.save
		flash[:notice] = "Material successfully created."
		render(:action => ''showmaterial'', :id => @material)
	else
		redirect_to(:action => ''newmaterial'')
	end
end

If not, make sure Material is in fact being saved successfully.

HTH,
Kevin Skoglund

> Hi,
>
> I''m struggling with this and I''m not sure if it is
obvious or dumb
> (or both).
>
> I have a basic create method like so:
>
> def creatematerial
>   @material = Material.new(params[:material])
>   if @material.save
>     flash[:notice] = "Material successfully created."
>   end
>
> Ok so far, but now I want to retrieve that object that was just  
> saved so that it can be used in the view. Something like...
>
>   @newmaterial = Material.find(@material.id)
>
> is what I was thinking, but that doesn''t work as @material still  
> has no id.
>
> The method finishes with a rendering of a table (this is an AJAX  
> called method)
>
>   render_partial ''listtable'', :layout => false
> end
>
> I want to grab the newly created object so I can hightlight and  
> display it in the view, but I don''t know how to retrieve it again!
>
> Any and all ideas are most appreciated.
>
> Chris.

> Rails saves your Model instance and adds the resulting id to its  
> attributes.  And you still "have" the object so there is no need
to
> refind it.
> HTH,
> Kevin Skoglund
Thanks, I should have figured that out myself! 

Chris.