laravel 5 - 关于验证，我很困惑

Question

对于许多应用程序，我的控制器：

public function store(Request $request)
{
  $this->validate($request, ['title' => 'required',
                             'date' => 'required',
                             'image_1' => 'required|mimes:png,jpeg',
                            ]);

  $user = Auth::user()->id;

  $report = new Report($request->all());
  $report->author_id = $user;

  $image = $request->file('image_1');
  $destinationPath = 'uploads/reports';
  $ext = $image->getClientOriginalExtension();
  $fileName = rand(11111,99999).'.'.$ext;

  $report->image_1 = $image->move($destinationPath, $fileName);
  $report->save();

  Session::flash('flash_message', 'Report added!');

  return redirect('dash/reports');
}

我的创建视图是：

@extends('layouts.app')

@section('content')
<div class="container">
    <h1>Crea un report</h1>
    <p>I campi sono tutti obbligatori. In caso di difficoltà, fare riferimento ad <strong><a href="#">eloquent</a></strong> l'assistente virtuale.</p>
    <hr/>

    {!! Form::open(['url' => '/dash/reports', 'files' => true, 'class' => 'form-horizontal']) !!}

           <div class="form-group {{ $errors->has('title') ? 'has-error' : ''}}">
                {!! Form::label('fake', 'Nome e cognome', ['class' => 'col-sm-3 control-label']) !!}
                <div class="col-sm-6">
                          <input class="form-control" id="disabledInput" type="text" placeholder="{{ $author->name }} {{ $author->surname}}" disabled>
                </div>
            </div>

           <div class="form-group {{ $errors->has('title') ? 'has-error' : ''}}">
                {!! Form::label('title', 'Servizio', ['class' => 'col-sm-3 control-label']) !!}
                <div class="col-sm-6">
                    {!! Form::text('title', null, ['class' => 'form-control', 'required' => 'required']) !!}
                    {!! $errors->first('title', '<p class="help-block">:message</p>') !!}
                </div>
            </div>

           <div class="form-group {{ $errors->has('title') ? 'has-error' : ''}}">
                {!! Form::label('date', 'Data', ['class' => 'col-sm-3 control-label']) !!}
                <div class="col-sm-6">
                    {!! Form::text('date', \Carbon\Carbon::now()->format('d/m/Y'), ['class' => 'form-control', 'required' => 'required']) !!}
                    {!! $errors->first('date', '<p class="help-block">:message</p>') !!}
                </div>
            </div>

            <div class="form-group {{ $errors->has('category_id') ? 'has-error' : ''}}">
                {!! Form::label('category_id', 'Cliente', ['class' => 'col-sm-3 control-label']) !!}
                <div class="col-sm-6">
                              {!! Form::select('category_id', $category, null, ['class' => 'form-control'] ) !!}
                    {!! $errors->first('category_id', '<p class="help-block">:message</p>') !!}
                </div>
                  </div>

             <div class="form-group {{ $errors->has('image_1') ? 'has-error' : ''}}">
                {!! Form::label('image_1', 'Upload report cartaceo', ['class' => 'col-sm-3 control-label']) !!}
                <div class="col-sm-6">
                  <p>Solo immagini .jpg/.png</p>
                    {!! Form::file('image_1', null, ['class' => 'form-control', 'required' => 'required']) !!}
                    {!! $errors->first('image_1', '<p class="help-block">:message</p>') !!}
                </div>
            </div>

          <div class="form-group">
              <div class="col-sm-offset-3 col-sm-3">
                  {!! Form::submit('Create', ['class' => 'btn btn-primary form-control']) !!}
              </div>
          </div>

    {!! Form::close() !!}

    @if ($errors->any())
        <ul class="alert alert-danger">
            @foreach ($errors->all() as $error)
                <li>{{ $error }}</li>
            @endforeach
        </ul>
    @endif

</div>
@endsection

现在，如果我提交一个有错误的表单，没有出现，为什么？此外，我的“会话闪存”不起作用，我只是使用apzzcoder / crud生成器，我只是按照指南。验证工作正常，但没有出现