ruby-on-rails-3 - 如何在此文件中使用 "Form_tag"而不是 "Form_for"

Question

我是 Ruby on Rails 的新手，Michael Hartl 的优秀著作《Ruby on Rails 教程》给了我很大帮助。我已经读到了第 8 章，现在正在做该章的练习。我在练习 1 中遇到(我假设一个典型的“新手”)问题。在这个练习中，它被要求“1.重构登录表单以使用 form_tag 代替 form_for”。两天来，我一直试图在 Stackoverflow、Google、Railscast 和许多其他“网络搜索”中寻找这方面的帮助，但我似乎没有找到回答这个问题所需的帮助。我试图用 form_tag 修改的文件如下:

<% provide(:title, "Sign in") %>
<h1>Sign in</h1>

<div class="row">
  <div class="span6 offset3">
    <%= form_for(:session, url: sessions_path) do |f| %>

      <%= f.label :email %>
      <%= f.text_field :email %>

      <%= f.label :password %>
      <%= f.password_field :password %>

      <%= f.submit "Sign in", class: "btn btn-large btn-primary" %>
     <% end %>

    <p>New user? <%= link_to "Sign up now!", signup_path %></p>
  </div>
</div>

我在这个应用程序中使用 Rails 3.2.3。有人能指出我正确的方向吗？谁能帮我解决这个问题？我将不胜感激。

这是使用 form_tag 的实现:

<% provide(:title, "Sign in") %>
<h1>Sign in</h1>

<div class="row">
  <div class="span6 offset3">
    <%= form_tag( url: sessions_path ) do  %>

      <%= label_tag :email %>
      <%= text_field_tag :email %>

      <%= label_tag :password %>
      <%= password_field_tag :password %>

      <%= submit_tag "Sign in", class: "btn btn-large btn-primary" %>
    <% end %>

    <p>New user? <%= link_to "Sign up now!", signup_path %></p>
  </div>
</div>

我正在使用 Rspec 2.9.0 及以下是失败的测试:

describe "signin page" do
    before { visit signin_path }

    it { should have_selector('h1',    text: 'Sign in') }
    it { should have_selector('title', text: 'Sign in') }
  end 

和

describe "with invalid information" do
            before { click_button "Sign in" }

            it { should have_selector('title', text: 'Sign in') }
            it { should have_selector('div.alert.alert-error', text: 'Invalid') }

            describe "after visiting another page" do
              before { click_link "Home" }
              it { should_not have_selector('div.alert.alert-error') }
            end
      end

和

describe "with valid information" do
            let(:user) { FactoryGirl.create(:user) }
            before do
              fill_in "Email",    with: user.email
              fill_in "Password", with: user.password
              click_button "Sign in"
            end

            it { should have_selector('title', text: user.name) }
            it { should have_link('Profile', href: user_path(user)) }
            it { should have_link('Sign out', href: signout_path) }
            it { should_not have_link('Sign in', href: signin_path) }

            describe "followed by signout" do
                    before { click_link "Sign out" }
                    it { should have_link('Sign in') }
            end
      end

这是我的路由文件:

SampleApp::Application.routes.draw do
  resources :users
  resources :sessions, only: [:new, :create, :destroy]


  get "users/new"

  root to: 'static_pages#home'

  match '/signup',  to: 'users#new'
  match '/signin',  to: 'sessions#new'
  match '/signout', to: 'sessions#destroy', via: :delete

  match '/help',    to: 'static_pages#help'
  match '/about',   to: 'static_pages#about'
  match '/contact', to: 'static_pages#contact'
end

Answer 1

我也刚刚完成了这个练习，所以我绝不是专家；但是，这是对我有用并通过了所有测试的代码:

../app/views/sessions/new.html.erb

<% provide(:title, "Sign in") %>
<h1>Sign in</h1>

<div class="row">
  <div class="span 6 offset 3">
    <%= form_tag sessions_path do %>

      <%= label_tag :email %>
      <%= text_field_tag :email, params[:email] %>

      <%= label_tag :password %>
      <%= password_field_tag :password %>

      <%= submit_tag "Sign in", class: "btn btn-large btn-primary" %>
    <% end %>

    <p>New User?<%= link_to "Sign Up Now", signup_path %> </p>
  </div>
</div>

我还需要更改 ../app/controllers/sessions_contoller

class SessionsController < ApplicationController

  def new
  end

  def create
    user = User.find_by_email(params[:email])
    if user && user.authenticate(params[:password])
      session[:user] = user.id
      sign_in user
      redirect_to user
    else
      flash.now[:error] = 'Invalid email/password combination'
      render 'new'
    end  
  end

  def destroy
    sign_out
    redirect_to root_path
  end
end

虽然这有效，但我不完全确定为什么会这样；如果有人可以解释为什么需要更改 Controller ，将不胜感激。我知道这可以作为一个单独的问题提出，但它与 OP 密切相关，我相信我们都会发现它不仅在理解如何使其工作以及为什么以这种方式工作方面都非常有用。以下是原始 View 和 Controller 文件:

原始'form_for' new.html.erb:

<% provide(:title, "Sign in") %>
<h1>Sign in</h1>

<div class="row">
  <div class="span6 offset3">
    <%= form_for(:session, url: sessions_path) do |f| %>

      <%= f.label :email %>
      <%= f.text_field :email %>

      <%= f.label :password %>
      <%= f.password_field :password %>

      <%= f.submit "Sign in", class: "btn btn-large btn-primary" %>
    <% end %>

    <p>New user? <%= link_to "Sign up now!", signup_path %></p>
  </div>
</div>

和原来的sessions_controller:

class SessionsController < ApplicationController

  def new
  end

  def create
    user = User.find_by_email(params[:session][:email])
    if user && user.authenticate(params[:session][:password])
      sign_in user
      redirect_to user
    else
      flash.now[:error] = 'Invalid email/password combination'
      render 'new'
    end  
  end

  def destroy
    sign_out
    redirect_to root_path
  end
end