Laravel 5 框架入门（四）完结篇

Page 和评论将使用 Eloquent 提供的“一对多关系”。最终，我们将得到一个个人博客系统的雏形，并布置一个大作业，供大家实战练习。

1. 初识 Eloquent

Laravel Eloquent ORM 是 Laravel 中非常重要的部分，也是 Laravel 能如此流行的原因之一。中文文档在：

1. http://laravel-china.org/docs/5.0/eloquent

2. http://www.golaravel.com/laravel/docs/5.0/eloquent/

在前面的教程中已经建立好的 learnlaravel5/app/Page.php 就是一个 Eloquent Model 类：

<?php namespace App;

use Illuminate\Database\Eloquent\Model;

class Page extends Model {

 //

}

若想进一步了解 Eloquent，推荐阅读系列文章：深入理解 Laravel Eloquent

2. 创建 Comment 模型

首先我们要新建一张表来存储 Comment，命令行运行：

代码如下:

php artisan make:model Comment

成功以后，修改 migration 文件 learnlaravel5/database/migrations/***_create_comments_table.php 的相应位置为：

Schema::create('comments', function(Blueprint $table)
{
 $table->increments('id');
 $table->string('nickname');
 $table->string('email')->nullable();
 $table->string('website')->nullable();
 $table->text('content')->nullable();
 $table->integer('page_id');
 $table->timestamps();
});

之后运行：

代码如下:

php artisan migrate

去数据库里瞧瞧，comments 表已经躺在那儿啦。

3. 建立“一对多关系”

修改 Page 模型：

<?php namespace App;

use Illuminate\Database\Eloquent\Model;

class Page extends Model {

 public function hasManyComments()
 {
  return $this->hasMany('App\Comment', 'page_id', 'id');
 }

}

搞定啦~ Eloquent 中模型间关系就是这么简单。

模型间关系中文文档：http://laravel-china.org/docs/5.0/eloquent#relationships

4. 前台提交功能

修改 Comment 模型：

<?php namespace App;

use Illuminate\Database\Eloquent\Model;

class Comment extends Model {

 protected $fillable = ['nickname', 'email', 'website', 'content', 'page_id'];

}

增加一行路由：

代码如下:

Route::post('comment/store', 'CommentsController@store');

运行以下命令创建 CommentsController 控制器：

代码如下:

php artisan make:controller CommentsController

修改 CommentsController：

<?php namespace App\Http\Controllers;

use App\Http\Requests;
use App\Http\Controllers\Controller;

use Illuminate\Http\Request;

use Redirect, Input;

use App\Comment;

class CommentsController extends Controller {

 public function store()
 {
 if (Comment::create(Input::all())) {
  return Redirect::back();
 } else {
  return Redirect::back()->withInput()->withErrors('评论发表失败！');
 }

 }

}

修改视图 learnlaravel5/resources/views/pages/show.blade.php：

@extends('_layouts.default')

@section('content')
 <h4>
  <a href="/">⬅️返回首页</a>
 </h4>

 <h1 style="text-align: center; margin-top: 50px;">{{ $page->title }}</h1>
 <hr>
 <div id="date" style="text-align: right;">
  {{ $page->updated_at }}
 </div>
 <div id="content" style="padding: 50px;">
  <p>
   {{ $page->body }}
  </p>
 </div>
 <div id="comments" style="margin-bottom: 100px;">

  @if (count($errors) > 0)
   <div class="alert alert-danger">
    <strong>Whoops!</strong> There were some problems with your input.<br><br>
    <ul>
     @foreach ($errors->all() as $error)
      <li>{{ $error }}</li>
     @endforeach
    </ul>
   </div>
  @endif

  <div id="new">
   <form action="{{ URL('comment/store') }}" method="POST">
    <input type="hidden" name="_token" value="{{ csrf_token() }}">
    <input type="hidden" name="page_id" value="{{ $page->id }}">
    <div class="form-group">
     <label>Nickname</label>
     <input type="text" name="nickname" class="form-control" style="width: 300px;" required="required">
    </div>
    <div class="form-group">
     <label>Email address</label>
     <input type="email" name="email" class="form-control" style="width: 300px;">
    </div>
    <div class="form-group">
     <label>Home page</label>
     <input type="text" name="website" class="form-control" style="width: 300px;">
    </div>
    <div class="form-group">
     <label>Content</label>
     <textarea name="content" id="newFormContent" class="form-control" rows="10" required="required"></textarea>
    </div>
    <button type="submit" class="btn btn-lg btn-success col-lg-12">Submit</button>
   </form>
  </div>

<script>
function reply(a) {
 var nickname = a.parentNode.parentNode.firstChild.nextSibling.getAttribute('data');
 var textArea = document.getElementById('newFormContent');
 textArea.innerHTML = '@'+nickname+' ';
}
</script>

  <div class="conmments" style="margin-top: 100px;">
   @foreach ($page->hasManyComments as $comment)

    <div class="one" style="border-top: solid 20px #efefef; padding: 5px 20px;">
     <div class="nickname" data="{{ $comment->nickname }}">
     @if ($comment->website)
      <a href="{{ $comment->website }}">
       <h3>{{ $comment->nickname }}</h3>
      </a>
     @else
      <h3>{{ $comment->nickname }}</h3>
     @endif
      <h6>{{ $comment->created_at }}</h6>
     </div>
     <div class="content">
      <p style="padding: 20px;">
       {{ $comment->content }}
      </p>
     </div>
     <div class="reply" style="text-align: right; padding: 5px;">
      <a href="#new" onclick="reply(this);">回复</a>
     </div>
    </div>

   @endforeach
  </div>
 </div>
@endsection

前台评论功能完成。

查看效果：

5. 后台管理功能

修改基础视图 learnlaravel5/resources/views/app.blade.php 为：

<!DOCTYPE html>
<html lang="en">
<head>
 <meta charset="utf-8">
 <meta http-equiv="X-UA-Compatible" content="IE=edge">
 <meta name="viewport" content="width=device-width, initial-scale=1">
 <title>Laravel</title>

 <link href="/css/app.css" rel="stylesheet">

 <!-- Fonts -->
 <link href='http://fonts.useso.com/css?family=Roboto:400,300' rel='stylesheet' type='text/css'>
</head>
<body>
 <nav class="navbar navbar-default">
 <div class="container-fluid">
  <div class="navbar-header">
  <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1">
   <span class="sr-only">Toggle Navigation</span>
   <span class="icon-bar"></span>
   <span class="icon-bar"></span>
   <span class="icon-bar"></span>
  </button>
  <a class="navbar-brand" href="#">Learn Laravel 5</a>
  </div>

  <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
  <ul class="nav navbar-nav">
   <li><a href="/admin">后台首页</a></li>
  </ul>
  <ul class="nav navbar-nav">
   <li><a href="/admin/comments">管理评论</a></li>
  </ul>

  <ul class="nav navbar-nav navbar-right">
   @if (Auth::guest())
   <li><a href="/auth/login">Login</a></li>
   <li><a href="/auth/register">Register</a></li>
   @else
   <li class="dropdown">
    <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false">{{ Auth::user()->name }} <span class="caret"></span></a>
    <ul class="dropdown-menu" role="menu">
    <li><a href="/auth/logout">Logout</a></li>
    </ul>
   </li>
   @endif
  </ul>
  </div>
 </div>
 </nav>

 @yield('content')

 <!-- Scripts -->
 <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
 <script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.1/js/bootstrap.min.js"></script>
</body>
</html>

修改后台路由组（增加了一行）：

Route::group(['prefix' => 'admin', 'namespace' => 'Admin', 'middleware' => 'auth'], function()
{
 Route::get('/', 'AdminHomeComtroller@index');
 Route::resource('pages', 'PagesController');
 Route::resource('comments', 'CommentsController');
});

创建 Admin\CommentsController ：

代码如下:

php artisan make:controller Admin/CommentsController

Admin/CommentsController 要有 查看所有、查看单个、POST更改、删除四个接口：

<?php namespace App\Http\Controllers\Admin;

use App\Http\Requests;
use App\Http\Controllers\Controller;

use Illuminate\Http\Request;

use App\Comment;

use Redirect, Input;

class CommentsController extends Controller {

 public function index()
 {
 return view('admin.comments.index')->withComments(Comment::all());
 }

 public function edit($id)
 {
 return view('admin.comments.edit')->withComment(Comment::find($id));
 }

 public function update(Request $request, $id)
 {
 $this->validate($request, [
  'nickname' => 'required',
  'content' => 'required',
 ]);
 if (Comment::where('id', $id)->update(Input::except(['_method', '_token']))) {
  return Redirect::to('admin/comments');
 } else {
  return Redirect::back()->withInput()->withErrors('更新失败！');
 }
 }

 public function destroy($id)
 {
 $comment = Comment::find($id);
 $comment->delete();

 return Redirect::to('admin/comments');
 }

}

接下来创建两个视图：

learnlaravel5/resources/views/admin/comments/index.blade.php：

@extends('app')

@section('content')
<div class="container">
 <div class="row">
  <div class="col-md-10 col-md-offset-1">
   <div class="panel panel-default">
    <div class="panel-heading">管理评论</div>

    <div class="panel-body">

    <table class="table table-striped">
     <tr class="row">
      <th class="col-lg-4">Content</th>
      <th class="col-lg-2">User</th>
      <th class="col-lg-4">Page</th>
      <th class="col-lg-1">编辑</th>
      <th class="col-lg-1">删除</th>
     </tr>
     @foreach ($comments as $comment)
      <tr class="row">
       <td class="col-lg-6">
        {{ $comment->content }}
       </td>
       <td class="col-lg-2">
        @if ($comment->website)
         <a href="{{ $comment->website }}">
          <h4>{{ $comment->nickname }}</h4>
         </a>
        @else
         <h3>{{ $comment->nickname }}</h3>
        @endif
        {{ $comment->email }}
       </td>
       <td class="col-lg-4">
        <a href="{{ URL('pages/'.$comment->page_id) }}" target="_blank">
         {{ App\Page::find($comment->page_id)->title }}
        </a>
       </td>
       <td class="col-lg-1">
        <a href="{{ URL('admin/comments/'.$comment->id.'/edit') }}" class="btn btn-success">编辑</a>
       </td>
       <td class="col-lg-1">
        <form action="{{ URL('admin/comments/'.$comment->id) }}" method="POST" style="display: inline;">
         <input name="_method" type="hidden" value="DELETE">
         <input type="hidden" name="_token" value="{{ csrf_token() }}">
         <button type="submit" class="btn btn-danger">删除</button>
        </form>
       </td>
      </tr>
     @endforeach
    </table>

    </div>
   </div>
  </div>
 </div>
</div>
@endsection

learnlaravel5/resources/views/admin/comments/edit.blade.php：

@extends('app')

@section('content')
<div class="container">
 <div class="row">
  <div class="col-md-10 col-md-offset-1">
   <div class="panel panel-default">
    <div class="panel-heading">编辑评论</div>

    <div class="panel-body">

     @if (count($errors) > 0)
      <div class="alert alert-danger">
       <strong>Whoops!</strong> There were some problems with your input.<br><br>
       <ul>
        @foreach ($errors->all() as $error)
         <li>{{ $error }}</li>
        @endforeach
       </ul>
      </div>
     @endif

     <form action="{{ URL('admin/comments/'.$comment->id) }}" method="POST">
      <input name="_method" type="hidden" value="PUT">
      <input type="hidden" name="_token" value="{{ csrf_token() }}">
      <input type="hidden" name="page_id" value="{{ $comment->page_id }}">
      Nickname: <input type="text" name="nickname" class="form-control" required="required" value="{{ $comment->nickname }}">
      <br>
      Email:
      <input type="text" name="email" class="form-control" required="required" value="{{ $comment->email }}">
      <br>
      Website:
      <input type="text" name="website" class="form-control" required="required" value="{{ $comment->website }}">
      <br>
      Content:
      <textarea name="content" rows="10" class="form-control" required="required">{{ $comment->content }}</textarea>
      <br>
      <button class="btn btn-lg btn-info">提交修改</button>
     </form>

    </div>
   </div>
  </div>
 </div>
</div>
@endsection

后台管理功能完成，查看效果：

6. 大作业
依赖于 Page 的评论功能已经全部完成，个人博客系统雏形诞生。在本系列教程的最后，布置一个大作业：构建出 Article 的前后台，并且加上 Article 与 Comment 的一对多关系，加入评论和评论管理功能。在做这个大作业的过程中，你将会反复地回头去看前面的教程，反复地阅读中文文档，会仔细阅读我的代码，等你完成大作业的时候，Laravel 5 就真正入门啦~~

以上所述就是本文的全部内容了，希望大家能够喜欢。