cocoon gem attributes not saving when creating new recipe

问题

In week 3 of mackenziechild-recipe_box, I am experiencing some issues with Cocoon. I have devise installed, as well, and my ingredients and directions attributes are not being saved when I create a new Recipe. But when I update an existing Recipe, everything is fine. The error message is:

Ingredients recipe must exist, directions recipe must exist

What am I doing wrong? I am using rails 5

app/models/recipe.rb

class Recipe < ApplicationRecord
  validates :title, :description, :image, presence: true
  has_attached_file :image, styles: { medium: "400x400#" }
  validates_attachment_content_type :image, content_type: /\Aimage\/.*\Z/
  belongs_to :user
  has_many :ingredients
  has_many :directions
  accepts_nested_attributes_for :ingredients, :reject_if => :all_blank, :allow_destroy => true
  accepts_nested_attributes_for :directions, :reject_if => :all_blank, :allow_destroy => true
end

app/controllers/recipes_controller.rb

def new
  @recipe = Recipe.new
  @recipe = current_user.recipes.build
end

def create
  @recipe = Recipe.new(recipe_params)
  @recipe = current_user.recipes.build(recipe_params)
  if @recipe.save
    # show a success flash message and redirect to the recipe show page
    flash[:success] = 'New recipe created successfully'
    redirect_to @recipe
  else
    # show fail flash message and render to new page for another shot at creating a recipe
    flash[:danger] = 'New recipe failed to save, try again'
    render 'new'
  end
end

def update
  if @recipe.update(recipe_params)
    # display a success flash and redirect to recipe show page
    flash[:success] = 'Recipe updated successfully'
    redirect_to @recipe
  else
    # display an alert flash and remain on edit page
    flash[:danger] = 'Recipe failed to update, try again'
    render 'edit'
  end
end

private

def recipe_params
  params.require(:recipe).permit(:title, :description, :image,
    directions_attributes: [:id, :step, :_destroy],
    ingredients_attributes: [:id, :name, :_destroy])
end

def recipe_link
  @recipe = Recipe.find(params[:id])
end

app/views/recipes/_ingredient_fields.html.haml partial

.form-inline.clearfix
.nested-fields
    = f.input :name, input_html: { class: 'form-input form-control' }
    = link_to_remove_association 'Remove', f, class: 'form-button btn btn-default'

app/views/recipes/_direction_fields.html.haml partial

.form-inline.clearfix
.nested-fields
    = f.input :step, input_html: { class: 'form-input form-control' }
    = link_to_remove_association 'Remove', f, class: 'form-button btn btn-default'

回答1:

But when I update an existing Recipe, everything is fine.

That's your answer. When you're creating a new recipe, you don't have the recipe object, because it's in the server memory. But when you're updating it, the recipe object is persisted.

That's why you're getting the Ingredients recipe must exist and directions recipe must exist error.

To fix that you have to add the inverse_of in the associations.

class Recipe
  has_many :ingredients, inverse_of: :recipe
  has_many :directions, inverse_of: :recipe

class Ingredient
  belongs_to :recipe, inverse_of: :ingredients

class Direction
  belongs_to :recipe, inverse_of: :directions

When you include the inverse_of, Rails now knows about those associations and will "match" them in memory.

More about inverse_of:

http://guides.rubyonrails.org/association_basics.html
http://api.rubyonrails.org/classes/ActiveRecord/Associations/ClassMethods.html

来源：https://stackoverflow.com/questions/37796204/cocoon-gem-attributes-not-saving-when-creating-new-recipe

标签

ruby-on-rails

ruby

cocoon-gem