nested attributes for has_one association

Make sure the params you expect are being sent. (check pluralization)

Can you copy and paste what the params look like from the server side?

13:44:29 INFO: Parameters: {"utf8"=>"✓" ....... 

That will help to get the naming the params correctly

If params naming is correct, but not being accepted for, then try specifying them explicitly

params.permit(:product => [:something, :stores_attributes => [:name, :address ]]) 

Update:

params.permit(:product => [ :name, :description, :permalink, :store_attributes => [:store_id, :supplier_id, :margin, :discount]]) 

Nested Attributes Examples:

http://edgeapi.rubyonrails.org/classes/ActionController/Parameters.html#method-i-permit

Look at the parameters in the console. You should see something like:

{ "product" => { "store_attributes" => { } } 

Which means you want to require :product (you want the product parameters) and permit the correct attributes for the store.

params.require(:product).permit(:store_attributes => [ :name, :location, :etc ]) 

When you require(:store) that means you expect a "store" key at the root of the parameters hash, which is not the case (and why your association is coming up empty.)

Assuming the controller in question is ProductsController, your strong parameter definition is incorrect.

Try:

params.require(:product).permit(:store_attributes) 

Or, to be more strict, permit only the required attributes:

params.require(:product).permit(store_attributes: [ :store_field1, :store_field2 ]) 

Where :store_field1 and :store_field2 are the attributes from store model that are in your form and you want to permit.

Update:

The following should work based on your log output.

params.require(:product).permit(:name, :description, :permalink, store_attributes: [ :margin, :discount ]) 

no this will not work. If you use nested_attributes with has_one association the these attributes should be written in plain not in the separate array.