Making an child before the parent is commited to DB

rubyonrails-talk
1

Say I have a model something like this Parent has_many kids Kid belongs_to Parent.

Now I have view for say a new Parent. I also have provided an AJAX form so that they can fill in all the children they have as well.

Whats the best way to go about adding a child to a parent at this stage. Nothing has been committed to the database. And I can't add a child to the database without having a parent. But the parent has not been created yet.

Thanks in advance for help! :slight_smile:

2

Take a look at ActiveRecord transactions.

If your params from the controller are :parent and :kids in your model method you would do a transaction:

def self.create_family(params)   Parent.transaction do     parent = Parent.create(params[:parent])     params[:kids].each do |kid|        parent.kids.create(kid)     end   end end

If one of the creates fails, they all get rolled back.

John.

3

Cheers for that, I think that'll work.

Another question: I have bunch of text_fields tags that get pushed onto the form via Ajax every time the user hits "add new child" now, if I wanted to add 4 kids to this family. Then I would have 4 text_fields.

Is it possible to group the text_fields in the view so that I can iterate through them in the code-behind?

4

Have you seen the Railscast on this subject, I think it more or less describes what you're trying to achieve.

5

Thanks for sharing that wonderful resource. It looks exactly like the thing I'm after!