I have these four models
class Comment < ActiveRecord::Base has_many :relationships has_many :advantages, :through => :relationships, :source => :resource, :source_type => 'Advantage' has_many :disadvantages, :through => :relationships, :source => :resource, :source_type => 'Disadvantage'
accepts_nested_attributes_for :advantages, :disadvantages end
class Advantage < ActiveRecord::Base has_many :relationships, :as => :resource has_many :comments, :through => :relationships end
class Disadvantage < ActiveRecord::Base has_many :relationships, :as => :resource has_many :comments, :through => :relationships end
class Relationship < ActiveRecord::Base belongs_to :resource, :polymorphic => true belongs_to :comment end
Since I have related commennts with advantages, disadvantages and have given the attribute `accepts_nested_attributes_for`, when I try to save new record of comments with new records of advantages, it saves. For example
params = { :comment => { :comment => 'This is a sample comment', :advantages_attributes => [ { :plus => 'This is a good product' }, { :plus => 'It has all the functionality' }, { :plus => 'Performs bette than others'} ] } }
comment = Comment.create(params[:comment])
This saves 3 records of advantages and 1 comment to the database and makes 3 entries in the relationship table.
But not always I want to create new entries for the advantages, if there are already existing advantages, I would like to send just the id, so only the relatioship table is being updated. So my params would be like this
params = { :comment => { :comment => 'This is a sample comment', :advantages_attributes => [ { :id => 1 }, { :plus => 'It has all the functionality' }, { :plus => 'Performs bette than others'} ] } }
Here I want a new comment to be created which has to be associated with the already existing advantage with `id => 1` and create new advantages for the next two and relate it with the comment, but when i try this directly it throws an error. How can I achieve this?
