Rails 4：验证失败时再次渲染控制器/动作

Question

已经有几个问题解决了这个问题：

• render/redirect to new action when validation fails (rails)
• Keeping validation errors after redirect from partial back to the same page that has the partial

我尝试实施一些推荐的解决方案，但未能解决我的问题。

所以我们开始吧。

在我的 Rails 4 应用程序中，有四个模型：

class User < ActiveRecord::Base
  has_many :administrations
  has_many :calendars, through: :administrations
  has_many :invitations, :class_name => "Invite", :foreign_key => 'recipient_id'
  has_many :sent_invites, :class_name => "Invite", :foreign_key => 'sender_id'
end

class Calendar < ActiveRecord::Base
  has_many :administrations
  has_many :users, through: :administrations
  has_many :invites
end

class Administration < ActiveRecord::Base
  belongs_to :user
  belongs_to :calendar
end

class Invite < ActiveRecord::Base
  belongs_to :calendar
  belongs_to :sender, :class_name => 'User'
  belongs_to :recipient, :class_name => 'User'
end

在这里，我们将重点关注Invite 和Calendar 模型。

在日历edit 视图中，我有一个表格给create 一个新的邀请：

<h2>Edit <%= @calendar.name %> calendar</h2>

<%= render 'form' %>

<h2>Invite new users to <%= @calendar.name %> calendar</h2>

<%= form_for @invite , :url => invites_path do |f| %>
    <%= f.hidden_field :calendar_id, :value => @invite.calendar_id %>
    <%= f.label :email %>
    <%= f.email_field :email %>
    <%= f.label "Role" %>
    <%= f.radio_button(:recipient_role, "Editor") %>
    <%= f.label "Editor" %>
    <%= f.radio_button(:recipient_role, "Viewer") %>
    <%= f.label "Viewer" %>
    <%= f.submit 'Send' %>
<% end %>

<%= link_to 'Show', calendar_path %> |
<%= link_to 'Back', calendars_path %>

–––––

更新：请注意，我已经为我的日历视图定义了 calendars.html.erb 布局，包括以下用于显示警报的代码：

<% flash.each do |key, value| %>
  <div class="alert alert-<%= key %>">
    <%= value %>
    </div>
<% end %>

–––––

在Invite 模型中，我想验证:email 和:recipient_role 的存在（用户通过表单提交的两个值），所以我将其添加到Invite 模型中：

validates :email, :recipient_role, presence: true

如果用户忘记填写这两个字段之一，我希望用户被重定向到带有错误消息的表单，这是我在InvitesController 中使用以下代码实现的：

class InvitesController < ApplicationController
  def create
    # some code
    if @invite.save
      # some code
    else
      format.html { render :template => "calendars/edit", notice: 'Invitation could not be sent.' }
    end
    redirect_to calendar_path(@calendar), notice: 'Invitation was successfully sent.'
  end

  private

  def invite_params
    params.require(:invite).permit(:email, :calendar_id, :recipient_role)
  end

end

特别是，我认为format.html { render :template => "calendars/edit", notice: 'Invitation could not be sent.' } 行可以让我做我想做的事，as recommended here。

但是，当我尝试提交至少包含一个空字段的表单时，我收到以下错误：

ArgumentError in InvitesController#create
too few arguments
end
    else
      format.html { render :template => "calendars/edit", notice: 'Invitation could not be sent.' }
    end
    redirect_to calendar_path(@calendar), notice: 'Invitation was successfully sent.'
  end

这是服务器日志：

Processing by InvitesController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"p+yxM9Tw3JiNw/6Chv9//N8uvWhMy0TqrudTu0y9D9zXCl6kK2LtCqPu1rvTGv5gOMBuv2RK/IX2MBpWUTelZw==", "invite"=>{"calendar_id"=>"3", "email"=>"test@example.com"}, "commit"=>"Send"}
  User Load (0.2ms)  SELECT  "users".* FROM "users" WHERE "users"."id" = ?  ORDER BY "users"."id" ASC LIMIT 1  [["id", 1]]
  Calendar Load (0.1ms)  SELECT  "calendars".* FROM "calendars" WHERE "calendars"."id" = ? LIMIT 1  [["id", 3]]
   (0.0ms)  begin transaction
   (0.0ms)  rollback transaction
Completed 500 Internal Server Error in 27ms (ActiveRecord: 1.3ms)

ArgumentError (too few arguments):
  app/controllers/invites_controller.rb:16:in `format'
  app/controllers/invites_controller.rb:16:in `create'


  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1@global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/_source.erb (3.7ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1@global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (1.5ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1@global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (0.9ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1@global/gems/actionpack-4.2.2/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout (54.0ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/_markup.html.erb (0.3ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/_inner_console_markup.html.erb within layouts/inlined_string (0.3ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/_prompt_box_markup.html.erb within layouts/inlined_string (0.4ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/style.css.erb within layouts/inlined_string (0.3ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/console.js.erb within layouts/javascript (36.5ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/main.js.erb within layouts/javascript (0.2ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/error_page.js.erb within layouts/javascript (0.5ms)
  Rendered /Users/TXC/.rvm/gems/ruby-2.2.1/gems/web-console-2.2.1/lib/web_console/templates/index.html.erb (83.2ms)

我做错了什么？

Answer 1

请做以下事情

def create
  # some code
  if @invite.save
    redirect_to calendar_path(@calendar), notice: 'Invitation was successfully sent.'
  else
    render template: "calendars/edit", notice: 'Invitation could not be sent.'
  end
end