CODEWITHSUNDEEP
ruby-on-railsruby-on-rails-3forms
KJF
KJF

Reputation: 2093

Rails 3 and fields_for with activemodel (tableless) object

I have a tableless model that I'm trying to generate some form fields for.

The form looks like so:

= form_for :users, url: users_path do |f|
  - books.each do |book|
    = f.fields_for :books, book do |bf|
      = bf.hidden_field :title, value: book.title
  = f.submit "Send"

What I'm expecting to be generated for each field is something like this:

<input name="users[books][][title]" type="hidden" value="Some Book Title">
<input name="users[books][][title]" type="hidden" value="Some Book Title">
<input name="users[books][][title]" type="hidden" value="Some Book Title">

However, what I'm actually getting is

<input name="users[books][title]" type="hidden" value="Some Book Title">
<input name="users[books][title]" type="hidden" value="Some Book Title">
<input name="users[books][title]" type="hidden" value="Some Book Title">

Which means when the form is submitted only the last input field is available as the previous two have been overwritten due to them referencing the same thing.

This works ok when the model has an active record backend but not when it's tableless.

Any suggestions?

Upvotes: 5

Views: 1268

Answers (4)

Kris
Kris

Reputation: 19948

Try this:

f.fields_for 'books[]', book do |bf|

Upvotes: 0

Azolo
Azolo

Reputation: 4383

Right now this is pretty hard to do with Rails 3.x. That will change with Rails 4 with the advent of ActiveModel::Model which will give all the base methods for your model to be ActionPack compatable.

However until Rails 4 is released a good standard to make your model ActionPack compatible is the ActionModel::Model module itself. It "should" work with the current stable Rails. Check it out

How you choose to implement this is your decision, but I would probably just download the file and throw it in my application's lib directory. That way I could just include it using

class Book
  include ActiveModel::Model
end

Easy Rails Form compatibility for custom models.

Upvotes: 0

Nubtacular
Nubtacular

Reputation: 1397

Welldan97 brings up a very important point. You need the persisted? method. I was getting an undefined method for the model name earlier. Check my gist out. It works, but not perfect by any means. https://gist.github.com/2638002

Upvotes: 0

welldan97
welldan97

Reputation: 3076

I think you need to add this to your users model

def books_attributes= attributes
  # do something with attributes
  # probably:
  # self.books = attributes.map{|k,v|Book.new(v)}
end

And also define persisted? method for Book instance. Make it just to return false.

And add f for your fields_for in view:

= f.fields_for :books, book do |bf|

I hope this will work.

Upvotes: 7

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