Rails 4 + boostrap：模态中的新记录

Question

我试图以模态打开新用户表单。我以为我是以错误的方式调用表单。

我收到了这个错误：

显示第1行引发的app / views / users / _form.html.erb：

表单中的第一个参数不能包含nil或为空* 提取的来源（第1行）：

1：＆lt;％= form_for（@ user）do | f | ％GT;

我知道这是因为我没有调用构建@user的新操作，但是我怎么能使用模态窗口呢？

的index.html

<%= link_to '<span class="glyphicon glyphicon-plus"></span> New User'.html_safe, new_user_path,
                    :remote => true, class: "btn btn-default btn-lg",
                     data: {toggle: "modal", target: "#myModal" } %>

    <!-- Modal -->
    <div class="modal fade" id="myModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
        <div class="modal-dialog">
            <div class="modal-content">
                <div class="modal-header">
                    <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
                    <h4 class="modal-title" id="myModalLabel">Modal title</h4>
                </div>
                <div class="modal-body">
                    <%= render 'form' %>
                </div>
                <div class="modal-footer">
                    <button type="button" class="btn btn-default" data-dismiss="modal">Close</button>
                    <button type="button" class="btn btn-primary">Save changes</button>
                </div>
            </div>
        </div>
    </div>

_form.html

<%= form_for(@user) do |f| %>
  <% if @user.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@user.errors.count, "error") %> prohibited this user from being saved:</h2>

      <ul>
      <% @user.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
      </ul>
    </div>
  <% end %>

  <div class="field">
    <%= f.label :name %><br>
    <%= f.text_area :name %>
  </div>
  <div class="field">
    <%= f.label :age %><br>
    <%= f.text_field :age %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

user_controller.rb

class UsersController < ApplicationController
    before_action :set_user, only: [:show, :edit, :update, :destroy]

    # GET /users
    # GET /users.json
    def index
        filters
    end

    def filters
        if request.xhr?
            if params[:priority] == 'low'
                @users = User.low
            elsif params[:priority] == 'high'
                @users = User.high
            else
                @users = User.all
            end
            render partial: "teste"
        else
            @users = User.all
        end
    end

    # GET /users/1
    # GET /users/1.json
    def show
    end

    # GET /users/new
    def new
        @user = User.new

    end

    # GET /users/1/edit
    def edit
    end

    # POST /users
    # POST /users.json
    def create
        @user = User.new(user_params)

        respond_to do |format|
            if @user.save
                format.html { redirect_to @user, notice: 'User was successfully created.' }
                format.json { render action: 'show', status: :created, location: @user }
            else
                format.html { render action: 'new' }
                format.json { render json: @user.errors, status: :unprocessable_entity }
            end
        end
    end

    # PATCH/PUT /users/1
    # PATCH/PUT /users/1.json
    def update
        respond_to do |format|
            if @user.update(user_params)
                format.html { redirect_to @user, notice: 'User was successfully updated.' }
                format.json { head :no_content }
            else
                format.html { render action: 'edit' }
                format.json { render json: @user.errors, status: :unprocessable_entity }
            end
        end
    end

    # DELETE /users/1
    # DELETE /users/1.json
    def destroy
        @user.destroy
        respond_to do |format|
            format.html { redirect_to users_url }
            format.json { head :no_content }
        end
    end

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

    # Never trust parameters from the scary internet, only allow the white list through.
    def user_params
        params.require(:user).permit(:name, :age)
    end
end