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Laravel 5 系列入门教程(四)【完结】

本教程示例代码见:https://github.com/johnlui/Learn-Laravel-5

大家在任何地方卡住,最快捷的解决方式就是去看我的示例代码。

本文是本系列教程的完结篇,我们将一起给 Page 加入评论功能,让游客在前台页面可以查看、提交、回复评论,同时我们将在后台完善评论管理功能,可以删除、编辑评论。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:

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:

php artisan make:model Comment  

成功以后,修改 migration 文件 learnlaravel5/database/migrations/*createcomments_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:

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://www.golaravel.com/docs/5.0/eloquent#relationships

扩展阅读:深入理解 Laravel Eloquent(三)——模型间关系(关联)

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:

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

运行以下命令创建 CommentsController 控制器:

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:

pic

pic

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="//cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
  <script src="//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 :

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:

pic

pic

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~~


教程(四)代码快照:https://github.com/johnlui/Learn-Laravel-5/archive/tutorial_4.zip


Laravel 5 系列入门教程【最适合中国人的 Laravel 教程】到此结束,谢谢大家!

原文:Laravel 5 系列入门教程(四)【最适合中国人的 Laravel 教程】


JohnLui
关于作者 JohnLui
PHP 框架 TinyLara 作者。