一、reponsitory

新建 app/Repositories/QuestionRepository.php

namespace App\Repositories;

use App\Question;
use App\Topic;

class QuestionRepository
{
    public function byIdWithTopics($id)
    {
        return Question::where('id', $id)->with('topics')->first();
    }

    public function create(array $attributes)
    {
        return Question::create($attributes);
    }

    public function normalizeTopic(array $topics)
    {
        return collect($topics)->map(function ($topic){
            if(is_numeric($topic)){
                Topic::find($topic)->increment('questions_count');
                return (int) $topic;
            }
            $newTopic = Topic::create(['name'=>$topic,'questions_count'=>1]);
            return $newTopic->id;
        })->toArray();
    }
}

修改 app/Http/Controllers/QuestionsController.php

protected $questionRepository;

public function __construct(QuestionRepository $questionRepository)
{
    $this->middleware('auth')->except(['index','show']);
    $this->questionRepository = $questionRepository;
}

public function store(StoreQuestionRequest $request)
{
    $topics = $this->questionRepository->normalizeTopic($request->get('topics'));
    $data = [
        'title' => $request->get('title'),
        'content' => $request->get('content'),
        'user_id' => Auth::id()
    ];
    $question = $this->questionRepository->create($data);
    $question->topics()->attach($topics);
    return redirect()->route('questions.show',[$question->id]);
}

public function show($id)
{
    $question = $this->questionRepository->byIdWithTopics($id);
    return view('questions.show', compact('question'));
}

二、编辑问题

修改 app/Repositories/QuestionRepository.php

public function byId($id)
{
    return Question::find($id);
}

修改 app/User.php

public function owns(Model $model)
{
    return $this->id == $model->user_id;
}

修改 app/Http/Controllers/QuestionsController.php

public function edit($id)
{
    $question = $this->questionRepository->byId($id);
    if(Auth::user()->owns($question)){
        return view('questions.edit', compact('question'));
    }
    return back();
}

public function update(StoreQuestionRequest $request, $id)
{
    $question = $this->questionRepository->byId($id);
    $topics = $this->questionRepository->normalizeTopic($request->get('topics'));
    $question->update([
        'title' => $request->get('title'),
        'content' => $request->get('content'),
    ]);
    $question->topics()->sync($topics);
    return redirect()->route('questions.show',[$question->id]);
}

修改 resources/views/questions/show.blade.php

新建 resources/views/questions/edit.blade.php

注意：vendor.ueditor.assets 必须在 js 后面

@section('js')
@include('vendor.ueditor.assets')