Laravel：尝试使唯一用户创建帖子时出错

Question

Right so im trying to make a website where a registered user can create a post. The issue i am having rigt now is getting the post to be added to the the database. It should work but im getting an error.

The error:

 Call to a member function posts() on null

The error points to my post controller class

<?php

use App\Post;
namespace App\Http\Controllers;

use Illuminate\Http\Request;

class postController extends Controller
{
    public function postCreatePost(Request $request){
        $post = new Post(); 
        $post->body = $request['body'];
        $request->user()->posts($post); //points here
        return redirect()->route('dashboard');
    }
}

This is my post migration up method:

public function up()
{
    Schema::create('posts', function (Blueprint $table) {
        $table->increments('id');
        $table->timestamps();
        $table->text('body');
        $table->integer('user_id');
    });
}

Post model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Post extends Model
{
    public function user(){
        return $this->belongsTo['App\User'];
    }
}

User model:

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Contracts\Auth\Authenticatable;

class User extends Model implements Authenticatable
{
    use \Illuminate\Auth\Authenticatable;
    public function posts(){
        return $this->hasMany('App\Post');
    }
}

The section the user types in:

<section class="row new-post">
    <div class="col-md-6 col-md-offset-3">
        <form action="{{ route('postcreate') }}" method="post">
            <div class="form-group">
                <textarea class="form-control" name="body" rows="5" placeholder="your post"></textarea>
            </div>
            <button type="submit" class="btn btn-primary">Create post</button>
            <input type="hidden" name="_token" value="{{ csrf_token() }}">
        </form>
    </div>
</section>

Answer 1

The problem is that on your controller you do:

$request->user()->posts($post); //points here

You are considering that user() will always return something.

If your route isn't guarded by the auth middleware, $request->user() may return null if there's no authenticated user.

So you have two options: Or you add the auth middleware, or you put an if on your code:

if ($request->user()) {
    $request->user()->posts($post);
}

However, this will fix the error but it won't create a post

public function postCreatePost(Request $request){
    $post = new Post(); 
    $post->body = $request['body'];
    $request->user()->posts($post); // This call isn't valid.
    return redirect()->route('dashboard');
}

The right way to do is:

public function postCreatePost(Request $request){
    $request->user()->posts()->create([
        'body' => $request->body
        // Here I'm assumming that the only field is the `body`,
        // but you may need other fields if they exists.
        // the `user_id` field will be automatically filled.
    ];

    return redirect()->route('dashboard');
}