Question

我是一名新开发者，我正在尝试将工作作为一个非常简单的博客。我想在博客中设置上一篇和下一篇文章的上一页和下一篇链接。这是我目前的代码。

POSTS CONTROLLER

public function move($id)
{
    $post = DB::table('posts')->find($id);

    $previous = DB::table('posts')->where('id', '<', $post->id)->max('id');

    $next = DB::table('posts')->where('id', '>', $post->id)->min('id');

    return view('posts.show')->with('previous', $previous)->with('next', $next);
}

WEB.PHP

<?php

Route::get('/', 'PostsController@index')->name('home');

Route::get('/posts/create', 'PostsController@create');
Route::post('/posts', 'PostsController@store');
//Route::get('/posts/{post}', 'PostsController@show');
Route::get('/posts/tags/{tag}', 'TagsController@index');
Route::post('/posts/{post}/comments','CommentsController@store');

Route::get('/posts/{id}/edit', 'PostsController@edit');
Route::get('/edit/{post}', 'PostsController@update');
Route::patch('/post/{post}', 'PostsController@update');

Route::get('/register', 'RegistrationController@create');
Route::post('/register', 'RegistrationController@store');

Route::get('/login', 'SessionsController@create');
Route::post('/login', 'SessionsController@store');

Route::get('/logout', 'SessionsController@destroy');

Route::get('/posts/{id}', 'PostsController@move');

SHOW.BLADE

@extends ('layouts.master')

@section ('content')

<div class="col-sm-8 blog-main">
<h1> {{$post->title}}</h1>

@if (count($post->tags))

    <ul>

        @foreach($post->tags as $tag)

            <li>

                <a href="/posts/tags/{{ $tag->name}}">

                {{ $tag->name }}

                </a>

            </li>

        @endforeach

    </ul>

@endif

{{$post->body}}

<hr>

<a href="/posts/{id}/edit">Modifica</a>

<hr>

<div class='comments'>

    <ul class="list-group">

    @foreach ($post->comments as $comment)

        <li class="lista-commenti">

            <strong>

                {{$comment->created_at->diffForHumans()}}: &nbsp;

            </strong>

            {{ $comment -> body}}

        </li>

    @endforeach

    </ul>

</div>

<hr>

<div>

    <div>

        <form method="POST" action="/posts/{{$post->id}}/comments">


            {{csrf_field()}} 

            <div>

                <textarea name="body" placeholder="Il tuo commento" class="form-control" required></textarea>

            </div>



            <div>

                <button type="submit" class="bottone">Invia Commento</button>

            </div>

        </form>

        @include('layouts.errors')

    </div>

    <div class="row">

        <ul>


        <li><a href="http://www.localhost.it/posts/{{ $previous }}"> Previous</a></li>

        <li><a href="http://www.localhost.it/posts/{{ $next }}"> Next</a>
</li>

        </ul>

    </div>

</div>

</div>

@endsection

post.php中

<?php

namespace App;

use Carbon\Carbon;

class Post extends Model
{


public function comments()

{
    return $this->hasMany(Comment::class);
}

public function user()

{
    return $this->belongsTo(User::class);
}


public function addComment($body)

{
    $user_id= auth()->id();

    $this->comments()->create(compact('user_id','body'));
}

public function scopeFilter($query, $filters)

    {

        if(!$filters)

        {
            return $query;
        }

    if ($month = $filters['month']) 
    {

    $query->whereMonth('created_at', Carbon::parse($month)->month);

    }

    if ($year = $filters['year']) {
    $query->whereYear('created_at', $year);
    }
    }


public static function archives()

{

    return static::selectRaw('year(created_at) year, monthname(created_at) month, count(*) published')
                    ->groupBy('year','month')
                    ->orderByRaw('min(created_at) desc')
                    ->get()
                    ->toArray();




}


public function tags(){

    return $this->belongsToMany(Tag::class);
}

}

这给我一个关于前一个和下一个未定义变量以及www的错误。

很抱歉，这是我的第一篇文章，我无法上传任何图片。希望有人可以帮助我。

由于

亚历山德罗

Answer 1

使用url()辅助方法：

    <li><a href="{{url('posts/' . $previous)}}"> Previous</a></li>

    <li><a href="{{url('posts/' . $next)}}"> Next</a></li>

修改：删除此Route::get('/posts/{post}', 'PostsController@show');行或更改move方法中的show方法代码。

对于您的新错误，请在顶部添加此行 -

use Illuminate\Support\Facades\DB;

Answer 2

当您前往post/1时，您正在执行show方法，而不是move。

另外，将代码更改为：

<li><a href="http://www.localhost.it/posts/{{ $previous }}"> Previous</a></li>
<li><a href="http://www.localhost.it/posts/{{ $next }}"> Next</a></li>

你说过，“还有关于www”。我很确定您没有收到有关$previous或$next的错误，但您收到有关www...的错误，因为您尝试在代码中使用文本作为变量

在PHP博客中链接上一个和下一个帖子

2 个答案: