在另一个控制器视图中调用表单时 NilClass:Class 的未定义方法“model_name”

Question

我有 2 个模型：

app/models/employee.rb:

class Employee < User
  has_many :insurances 
end

app/models/insurance.rb:

 class Insurance < ActiveRecord::Base
   belongs_to :employee
 end

app/controllers/employees_controller.rb:

class EmployeesController < ApplicationController
  before_action :set_employee, only: [:show, :edit, :update, :destroy]
  before_action :employee_params, only: [:create, :update]
  # GET /employees
  # GET /employees.json
  def index
    @employees = Employee.all
  end

  # GET /employees/1
  # GET /employees/1.json

  def show
    @employee = Employee.find(params[:id])
  end

  # GET /employees/new
  def new
    @employee = Employee.new
  end

  # GET /employees/1/edit
  def edit
     @employee = Employee.find(params[:id])
  end

  # POST /employees
  # POST /employees.json
  def create
    @employee = Employee.new(employee_params)

    respond_to do |format|
      if @employee.save
        format.html { redirect_to employees_url, notice: "#{@employee.first_name} was successfully created." }
        format.json { render :index, status: :created, location: @employee }
      else
        format.html { render :new }
        format.json { render json: @employee.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /employees/1
  # PATCH/PUT /employees/1.json
  def update
    respond_to do |format|
      if @employee.update(employee_params)
        format.html { redirect_to employees_url, notice: "#{@employee.first_name} was successfully updated."}
        format.json { render :index, status: :ok, location: @employee }
      else
        format.html { render :edit }
        format.json { render json: @employee.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /employees/1
  # DELETE /employees/1.json
  def destroy
    @employee.destroy
    respond_to do |format|
      format.html { redirect_to employees_url, notice: 'Employee was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_employee
      @employee = Employee.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def employee_params
      if params[:employee][:password].blank? && params[:employee][:password_confirmation].blank?
          params[:employee].delete(:password)
          params[:employee].delete(:password_confirmation)
      end
      params[:employee].permit(:email, :password, :employee_id,:employee_work_id, :first_name, :middle_name, :last_name, :gender, :date_of_birth, :driver_license_no, :driver_license_expiry_date, :martial_status, :nationality, :office_address, :residence_address, :city, :state_province, :zip_code, :country, :work_number, :mobile_number, :home_number, :other_email)

    end
end

app/controllers/insurance_controller.rb:

    class InsurancesController < ApplicationController
  before_action :set_insurance, only: [:show, :edit, :update, :destroy]

  respond_to :html

  def index
    @insurances = Insurance.all
    respond_with(@insurances)
  end

  def show
    respond_with(@insurance)
  end

  def new
    @insurance = Insurance.new
    respond_with(@insurance)
  end

  def edit
  end

  def create
    @employee = Employee.find(params[:employee_id])
    @insurance = @employee.insurances.create(insurance_params)
    redirect_to employee_path(@employee)  
  end

  def update
    @insurance.update(insurance_params)
    respond_with(@insurance)
  end

  def destroy
    @insurance.destroy
    respond_with(@insurance)
  end

  private
    def set_insurance
      @insurance = Insurance.find(params[:id])
    end

    def insurance_params
      params.require(:insurance).permit(:name_of_dependent, :relationship, :name, :of_spouse, :children, :date_of_birth, :policy_number, :policy_provider, :policy_type)
    end
end

app/views/insurances/_show.html.erb:

   - if @employee.insurances.exists?
  - @employee.insurances.each do |emp|
    %p
      %strong Name of dependent:
      = emp.name_of_dependent
    %p
      %strong Relationship:
      = emp.relationship
    %p
      %strong Name of spouse:
      = emp.name_of_spouse
    %p
      %strong Children:
      = emp.children
    %p
      %strong Date of birth:
      = emp.date_of_birth
    %p
      %strong Policy number:
      = emp.policy_number
    %p
      %strong Policy provider:
      = emp.policy_provider
    %p
      %strong Policy type:
      = emp.policy_type
- else
  = simple_form_for([:employee,@insurance]) do |f|
    = f.error_notification
    .form-inputs
      = f.input :name_of_dependent
      = f.input :relationship
      = f.input :name_of_spouse
      = f.input :children
      = f.input :date_of_birth
      = f.input :policy_number
      = f.input :policy_provider
      = f.input :policy_type
    .form-actions
      = f.button :submit

app/views/employees/show.html.haml:

%p
  %strong Title:
  = @employee.full_name
%p
  %strong Text:
  = @employee.gender
%p
  %strong Insurance Details:
  = render :partial => 'insurances/show', locals: { employee: @employee }

在 employees/show 中，当我呈现 insurances/show 时，显示条件工作正常，当没有记录时，不显示创建表单，它列出错误如下：

NilClass:Class

的未定义方法“model_name”

我尝试使用 = simple_form_for([:employee,Insurance.new], :url =>{:controller => "insurances", :action => :create) do |f|但这并没有解决我的问题。

Answer 1

在部分内部使用局部变量：employee 而不是 @employee。

当你渲染一个partial并使用locals:传入一个变量时，它实际上是作为局部变量传入的。同名的实例变量将为零。