Polymorphic has-many-through accepts_nested_attributes_for error - ruby-on-rails-4

Question

I have a problem with my following setup. It is a polymorphic n:m association between the feature, page and slide model. the join model is the slideshow model.
feature.rb - a model in a refinerycms extension
module Refinery
module MyExtension
class Feature < Refinery::Core::BaseModel
# associations
has_many :slideshows, :as => :slideable, :class_name => "::Refinery::MyExtension::Slideshow"
has_many :slides, :through => :slideshows, :class_name => "::Refinery::MyExtension::Slide"
accepts_nested_attributes_for :slides, :allow_destroy => :false
end
end
end
page_decorator.rb - a decorator for the refinery page model
Refinery::Page.class_eval do
# associations
has_many :slideshows, :as => :slideable, :class_name => "Refinery::MyExtension::Slideshow"
has_many :slides, :through => :slideshows, :class_name => "Refinery::MyExtension::Slideshow"
end
slide.rb - a model in a refinerycms extension
module Refinery
module MyExtension
class Slide < Refinery::Core::BaseModel
# associations
has_many :slideshows, :class_name => "::Refinery::MyExtension::Slideshow"
has_many :pages, :through => :slideshows, :source => :slideable, :source_type => "::Refinery::Page"
has_many :features, :through => :slideshows, :source => :slideable, :source_type => "::Refinery::MyExtension::Feature"
end
end
end
slideshow.rb - a model in a refinerycms extension
module Refinery
module MyExtension
class Slideshow < Refinery::Core::BaseModel
# associations
belongs_to :slide, :class_name => "::Refinery::MyExtension::Slide"
belongs_to :slideable, :polymorphic => true
accepts_nested_attributes_for :slide, :allow_destroy => :false
end
end
end
I think the associations are correct, but I have a problem creating new slides within the feature#form.
feature-form:
<%= form_for [refinery, :my_extension_admin, #feature] do |f| -%>
<%= f.text_field :field1 %>
<%= f.text_field :field2 %>
<%= "some-more-fields..." %>
<% slideshows = #feature.slideshows.empty? ? #feature.slideshows.build : #feature.slideshows %>
<%= f.fields_for(:slideshows, slideshows) do |slideshow_form| %>
<%= slideshow_form.hidden_field :position, :value => 0 %>
<% slide = slideshow_form.object.slide.nil? ? slideshow_form.object.build_slide : slideshow_form.object.slide %>
<%= slideshow_form.fields_for(:slide, slide) do |slide_form| %>
<%= slide_form.text_field :a_field -%>
<%= slide_form.text_field :another_field -%>
<% end %>
<% end %>
<% end %>
If I hit "save" I get following error:
::Refinery::MyExtension::Slideshow(#70206105711540) expected, got Array(#70206014033940)
My params hash looks as following:
{"utf8"=>"✓", "authenticity_token"=>"my-token", "switch_locale"=>"de", "feature"=>{"field1"=>"a value", "field2"=>"some value", "slideshows"=>{"position"=>"0", "slide_attributes"=>{"a_field"=>"some value", "another_field"=>"some value"}}}, "action"=>"create", "controller"=>"refinery/my_extension/admin/features", "locale"=>:de}
My controller looks as following:
module Refinery
module MyExtension
module Admin
class FeaturesController < ::Refinery::AdminController
crudify :'refinery/my_extension/feature', :title_attribute => 'name', :xhr_paging => true
def feature_params
params.require(:feature).permit(:field1, :field2, :slideshows => [:position, :slide => [:a_field, :anothter_field]])
end
end
end
end
end
I use Rails 4.1.5 and refinerycms. But I think it has nothing to do with refinerycms, just with normal Rails behavior.
I already took a look at following resources:
ActiveRecord::AssociationTypeMismatch when attempting to save nested attributes in Rails
Has Many Through Association Polymorphic Error
accepts_nested_attributes_for with has_many => :through Options
Anybody an idea what I am missing?

Answer 1

try to create method "new" something like this
def new
#feature = ::Refinery::MyExtension::Feature.new
#feature.slideshows.build
end
and edit method
def edit
#feature = ::Refinery::MyExtension::Feature.find(params[:id])
#feature.slideshows.build
end