persistence by reachability

rubyonrails-talk
1

Hello guys, I have these models

class Farmer < ActiveRecord::Base

     has_many :cows

  end

class Cow < ActiveRecord::Base

  set_table_name :cows   belongs_to :farmer

end

...

graph = Farmer.find(x) # Retrieves four cows of x

graph.cows[1].name = "Trottolina"

graph.save

while adding a new cow to collection works perfectly fine, ActiveRecord doesn't update for reachability the associated record why?

2

What do you mean by that?

Fred

3

Hey Vogon,

You should check out the autosave feature in ActiveRecord. I think this is what you’re looking for :slight_smile: http://api.rubyonrails.org/classes/ActiveRecord/AutosaveAssociation.html

Cheers, Richard

4

Thanks for reply Frederick, What I wrote is really obscure, so let me explain:

replacing the name 'graph' with farmer, imagine a situation where in the database there is a record that I retrieve with :

  farmer = Farmer.find(2)

Well, this farmer has many cows associated, and these cows are loaded on the collection named 'cows', an Array with Cow objects; then suppose to change the value of attribute 'name', of one of these objects of the collection, perhaps the second cow:

farmer.cows[1].name = "another_name"

and then suppose to update all with :

farmer.save

In other ORM frameworks this results in updating the 'dirty' object of the collection but not in Active Record, why?

5

Richard Ramsden wrote in post #975325:

Hey Vogon,

You should check out the autosave feature in ActiveRecord. I think this is what you're looking for :slight_smile: ActiveRecord::AutosaveAssociation

Cheers, Richard

On Sun, Jan 16, 2011 at 11:08 AM, Frederick Cheung <

Thanks Richard, I didn't see your reply, YES AutosaveAssociation is what I'm looking for!