Hi Rob, Thanks for the reply. I have managed to get this code done. What I wanted really was how to save and update.
For instance, I want to know how to create the instance of the invoice, and the invoice lines. When updating the invoice, its line items with the respective order should be also updated in the db. If I remove one item from the list, the order of each item should be adjusted. Let's say I have the following invoiceitems: item, qty, price, order 1, 3, 12.0, 1 6, 1, 23.0, 2 3, 2, 11.0, 3 if I remove item with order 2, I should get the following: 1, 3, 12.0, 1 3, 2, 11.0, 2 What I am after is a view + controller solution. Thanks in advance. Regards, Fidel. On Sat, Sep 19, 2009 at 11:59 PM, Rob Biedenharn <[email protected]> wrote: > > On Sep 19, 2009, at 5:35 PM, Fidel Viegas wrote: >> Hi all, >> >> I am implementing a simple invoice system where I have invoiceLines, >> and where I want to keep the order of the lines. I have tried to >> google around but have not found any sample on this. >> >> Can someone give me a pointer to something that uses a set where the >> order is kept? >> >> Thanks in advance. >> >> Regards, >> >> Fidel. > > > Well, that would be an Array. Or in the likely case that your data is > accessed with ActiveRecord models, an AssociationProxy that will > behave mostly like an Array. You will probably find something like > the following in any reasonable discussion about the has_many/ > belongs_to associations. If you don't specify a default order for the > association, then you'll get the invoice_lines back in whatever order > the database prefers (often the order in which the database records > were created). > > ## Models > class Invoice < ActiveRecord::Base > has_many :invoice_lines, :order => 'line_number' > end > class InvoiceLine < ActiveRecord::Base > belongs_to :invoice > end > > ## migration (schema) > create_table :invoices do |t| > t.integer :number > t.date :inv_date > t.date :due_date > # etc. > end > > create_table :invoice_lines do |t| > t.references :invoice > # equiv. to t.integer :invoice_id > t.integer :line_number > t.string :sku > t.integer :quantity > t.decimal :unit_price, :precision => 8, :scale => 2 > # etc. > end > > ## use in a controller > > @invoice = Invoice.find_by_number(params[:invoice][:number]) > > @invoice.invoice_lines > #=> an array-like set of InvoiceLine records > > -Rob > > Rob Biedenharn http://agileconsultingllc.com > [email protected] > > > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
