Adding extra value to an object

Hello friends ,
I have a clear method here ::

def create
@invoiceitems =[:invoiceitems])
@invoiceitems[“invoice_id”] = params[:id]
flash[:notice] = ‘Invoiceitems was successfully created.’
redirect_to :action => ‘new’,:id => params[:id]
render :action => ‘new’

In the table invoiceitems I have a field called invoice_id which is a
foreign key and the primary key of the table invoices. I need to save
the invoiceid which is in the URL itself (params[:id]) before saving
.How can I do it .
The above method is not storing that .

Thanx and regards,
Naroor R.,

Naroor, how did you set up the association in your Invoiceitems model?
I suspect either the association is not set up right, or the :id
parameter is not coming in with the request. A functional test for
this action would be a good idea. (goes for all your other actions as
well :slight_smile:

As an aside, it will benefit you in the long to be consistent with
plural/singular in naming your identifiers. Consider calling your
class Invoiceitem as opposed to Invoiceitems, same for the instance


Hi Gerret,

class Invoice < ActiveRecord::Base
belongs_to :company
has_many :invoiceitems

class Invoiceitems < ActiveRecord::Base
belongs_to :invoice

These are my model entries .Please let me know what wrong here ?

Thanx and regards,
Naroor R.

Gerret ,
Another try that I made was to create a hidden text box and add the
params[:id] to that and save the whole contents .There also it didnt
work .

Please comment .
Thanx and regards ,
Naroor R.


your model files are correct.

I suggest we clean up the names of your identifies before looking
further at the problem. I think this is where part of the problem
stems from. AFAICT your create method intends to save a single
Invoiceitem, attach it to an Invoice, and then redirect to a screen
where another Invoiceitem may be added.

So I suggest two cleanup steps:

  1. Rename your Invoicesitems class to Invoiceitem. Singular instead of
    Plural. That’s the rails convention, and if you follow it, your code
    will read much more easily. Same goes for your instance variable
    @invoiceitems. Make it @invoiceitem instead.
    I suspect you used “./script/generate invoiceitems” to create your
    controller. You should pass a singular parameter, so re-run
    ./script/generate like “./script/generate invoiceitem”. That will give
    you a class Invoiceitem instead of Invoiceitems (your table must still
    be called ‘invoiceitems’, plural. Which makes sense, because it
    contains many items).

  2. In your create method, you are using the parameter :id is the
    invoice id. Don’t. In your form, have a parameter :invoice_id, and
    don’t use the :id parameter. This makes it very clear which class your
    id-parameter belongs to. With your current code, you implicitly
    initialize to params[:id], which is not what you

With those two changes done your method will look like this:

def create
@invoiceitem =[:invoiceitem])
flash[:notice] = ‘Invoiceitem was successfully created.’
redirect_to :action => ‘list’
render :action => ‘new’

Because we’ve stuck to naming conventions, the line

@invoiceitems[“invoice_id”] = params[:invoiceitem][:invoice_id]

become superfluous, because code to that effect is automatically
performed by[:invoiceitem]).

Of course you need to supply a parameter [:invoiceitem][:incoide_id].
In your new.rhtml, you might do this:

<%= hidden_field ‘invoiceitem’, ‘incoice_id’, :value => %>

Good luck, hope this helps. Use functional tests for debugging, its a
real timesave once you’re used to them.