Issue: Instead of updating nested attributes, they are being created on top of the existing nested attributes when I hit the #update
action of the associated features_controller.rb
Likely Cause: I think the problem lies in my lack of understanding in Rails' form_for
. I think the breakdown is in my views, how I render the persisting nested attributes, and/or how I fail to specify the nested attribute's id, causing it to simply create a new one
feature.rb
class Feature < ActiveRecord::Base
...
has_many :scenarios
accepts_nested_attributes_for :scenarios,
allow_destroy: true,
reject_if: :all_blank
...
end
features_controller.rb
def update
...
project = Project.find(params[:project_id])
@feature = Feature.find(params[:id])
if @feature.update_attributes(feature_params)
# checking feature_params looks good...
# feature_params['scenarios'] => { <correct object hash> }
redirect_to project
else
render :edit
end
end
...
private
def feature_params
params.require(:feature).permit(:title, :narrative, :price, :eta, scenarios_attributes[:description, :_destroy])
end
_form.html.haml (simplified)
= form_for [@project, @feature] do |f|
...
- if @feature.new_record? -# if we are creating new feature
= f.fields_for :scenarios, @feature.scenarios.build do |builder|
= builder.label :description, "Scenario"
= builder.text_area :description, rows: "3", autocomplete: "off"
- else -# if we are editing an existing feature
= f.fields_for :scenarios do |builder|
= builder.label :description, "Scenario"
= builder.text_area :description, rows: "3", autocomplete: "off"
I'm sure there's a nicer way to achieve the if @feature.new_record?
check. I'm also using a few Javascript hooks to create dynamic nested attribute forms (which I've left out), heavily influenced by Railscast #196 Nested Model Form (revised)
I would love a really nice Rails-y implementation of dealing with these sorts of nested forms.
Try adding :id
to the :scenario_attributes
portion of your feature_params
method. You only have the description field and the ability to allow a destroy.
def feature_params
# added => before nested attributes
params.require(:feature).permit(:id, :title, :narrative, :price, :eta, scenarios_attributes => [:id, :description, :_destroy])
end
As @vinodadhikary suggested, you no longer need to check if feature is a new record, since Rails, specifically using the form_for
method, will do that for you.
Update:
You don't need to define if @feature.new_record? ... else
in your form. It will be taken care by Rails when you use form_for
. Rails checks if the action is going to be create
or update
based on object.persisted?
, so, you can update your form to:
= form_for [@project, @feature] do |f|
...
= f.fields_for :scenarios, @feature.scenarios.build do |builder|
= builder.label :description, "Scenario"
= builder.text_area :description, rows: "3", autocomplete: "off"