问题
I posted an earlier question about this and was advised to read lots of relevant info. I have read it and tried implementing about 30 different solutions. None of which have worked for me.
Here's what I've got.
I have a Miniatures model. I have a Manufacturers model. Miniatures have many manufacturers THROUGH a Productions model.
The associations seem to be set up correctly as I can show them in my views and create them via the console. Where I have a problem is in letting the Miniatures NEW and EDIT views create and update to the Productions table.
In the console the command @miniature.productions.create(manufacturer_id: 1)
works, which leads me to believe I should be able to do the same in a form.
I THINK my problem is always in the Miniatures Controller and specifically the CREATE function. I have tried out a ton of other peoples solutions there and none have done the trick. It is also possible that my field_for stuff in my form is wrong but that seems less fiddly.
I've been stuck on this for days and while there are other things I could work on, if this association isn't possible then I'd need to rethink my entire application.
The form now creates a line in the Productions table but doesn't include the all important manufacturer_id.
Any help VERY much appreciated.
My New Miniature form
<% provide(:title, 'Add miniature') %>
<h1>Add a miniature</h1>
<div class="row">
<div class="span6 offset3">
<%= form_for(@miniature) do |f| %>
<%= render 'shared/error_messages', object: f.object %>
<%= f.label :name %>
<%= f.text_field :name %>
<%= f.fields_for :production do |production_fields| %>
<%= production_fields.label :manufacturer_id, "Manufacturer" %>
<%= production_fields.select :manufacturer_id, options_from_collection_for_select(Manufacturer.all, :id, :name) %>
<% end %>
<%= f.label :release_date %>
<%= f.date_select :release_date, :start_year => Date.current.year, :end_year => 1970, :include_blank => true %>
<%= f.submit "Add miniature", class: "btn btn-large btn-primary" %>
<% end %>
</div>
</div>
Miniatures controller
class MiniaturesController < ApplicationController
before_action :signed_in_user, only: [:new, :create, :edit, :update]
before_action :admin_user, only: :destroy
def productions
@production = @miniature.productions
end
def show
@miniature = Miniature.find(params[:id])
end
def new
@miniature = Miniature.new
end
def edit
@miniature = Miniature.find(params[:id])
end
def update
@miniature = Miniature.find(params[:id])
if @miniature.update_attributes(miniature_params)
flash[:success] = "Miniature updated"
redirect_to @miniature
else
render 'edit'
end
end
def index
@miniatures = Miniature.paginate(page: params[:page])
end
def create
@miniature = Miniature.new(miniature_params)
if @miniature.save
@production = @miniature.productions.create
redirect_to @miniature
else
render 'new'
end
end
def destroy
Miniature.find(params[:id]).destroy
flash[:success] = "Miniature destroyed."
redirect_to miniatures_url
end
private
def miniature_params
params.require(:miniature).permit(:name, :release_date, :material, :scale, :production, :production_attributes)
end
def admin_user
redirect_to(root_url) unless current_user.admin?
end
def signed_in_user
unless signed_in?
store_location
redirect_to signin_url, notice: "Please sign in."
end
end
end
Miniature model
class Miniature < ActiveRecord::Base
has_many :productions, dependent: :destroy
has_many :manufacturers, :through => :productions
accepts_nested_attributes_for :productions
validates :name, presence: true, length: { maximum: 50 }
validates :material, presence: true
validates :scale, presence: true
validates_date :release_date, :allow_blank => true
def name=(s)
super s.titleize
end
end
Production model
class Production < ActiveRecord::Base
belongs_to :miniature
belongs_to :manufacturer
end
Manufacturer model
class Manufacturer < ActiveRecord::Base
has_many :productions
has_many :miniatures, :through => :productions
validates :name, presence: true, length: { maximum: 50 }
accepts_nested_attributes_for :productions
end
回答1:
Instead of calling:
@production = @miniature.productions.create
Try Rails' "build" method:
def new
@miniature = Miniature.new(miniature_params)
@miniature.productions.build
end
def create
@miniature = Miniature.new(miniature_params)
if @miniature.save
redirect_to @miniature
else
render 'new'
end
end
Using the build method uses ActiveRecord's Autosave Association functionality.
See http://api.rubyonrails.org/classes/ActiveRecord/AutosaveAssociation.html
You also need to update your params method, e.g.
def miniature_params
params.require(:miniature).permit(:name, :release_date, :material, :scale, productions_attributes: [:manufacturer_id])
end
Also your fields_for should be plural (I think)...
<%= f.fields_for :productions do |production_fields| %>
来源:https://stackoverflow.com/questions/19229638/absolutely-stuck-trying-to-create-nested-association-in-rails-form-with-has-many