Rails 5 中 accepts_nested_attributes_for 不起作用。
如果你在 Rails 5 中使用 accepts_nested_attributes_for 并且是 has_many 的关系，那么你可能需要使用 inverse_of 这个选项。
具体见下面实例
有三个 model 分别为 course, section 与 assignments。
class Course < ApplicationRecord
has_many :sections, dependent: :destroy
has_many :assignments, through: :sections
end
class Section < ApplicationRecord
belongs_to :course
has_many :assignments, dependent: :destroy
accepts_nested_attributes_for :assignments, allow_destroy: true
end
class Assignment < ApplicationRecord
belongs_to :section
end
class Admin::SectionsController < ApplicationController
before_action :authenticate_user!
before_action :admin_required
def new
@course = Course.find(params[:course_id])
@section = @course.sections.new
@section.assignments.build
end
def create
@section = Section.new(section_params)
@course = Course.find(params[:course_id])
@section.course_id = @course.id
if @section.save
redirect_to admin_course_sections_path(@course)
else
render :new
end
end
private
def section_params
params.require(:section).permit(:title, :content, :course_id,
assignments_attributes: [:id, :title, :content, :_destroy])
end
end
一直未能成功添加 assignments
后来加上了 inverse_of 之后，马上可以了。
class Section < ApplicationRecord
belongs_to :course
has_many :assignments, dependent: :destroy, inverse_of: :section
accepts_nested_attributes_for :assignments, allow_destroy: true
end