Laravel 未定义的变量停止if else语句的工作

在我的应用程序中，用户可以创建个人“组”。每个用户都有一个

用户配置文件

，我显示了他们在配置文件上创建的组，就像这样

{{ucwords（trans（$groupCreated->group_title））}

非常有效

我希望他们的组标题位于绿色框内，如果用户未创建组，则显示灰色框

以下是绿色方框的完整代码：

@foreach($user->groupsCreated as $groupCreated)<div class="alert alert-success" role="alert"><a href="{{ route('groups.show',$groupCreated->id)}}"> {{ ucwords(trans($groupCreated->group_title)) }}</a></div>@endforeach

我得到的错误是

未定义变量：groupCreated

这是我的GroupController.php

<?php

namespace App\Http\Controllers;

use App\Group;
use Illuminate\Http\Request;

// All Groups pages require login except 'show'
class GroupsController extends Controller
{

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

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        $groups = Group::where('created_by_user_id', auth()->id())->get();

        return view('groups/index', compact('groups'));
    }

    /**
     * Store the group that a user has joined in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function join(Request $request)
    {
        $request->validate([
            'group_id' => 'required',
        ]);

        $user_id = auth()->id();
        $group = Group::find($request->get('group_id'));

        if (!$group->isLoggedInUserJoined())
            $group->joinedUsers()->attach($user_id);

        $redirect = $request->get('redirect', 'groups/joined');

        return redirect($redirect)->with('success', 'You joined the group!!');
    }

    /**
     * Remove the user from a group that they have joined in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function unjoin(Request $request)
    {
        $request->validate([
            'group_id' => 'required',
        ]);

        $group = Group::find($request->get('group_id'));

        if ($group->isLoggedInUserJoined())
            $group->joinedUsers()->detach(auth()->id());

        $redirect = $request->get('redirect', 'groups/joined');

        return redirect($redirect)->with('success', 'You\'ve left the group.');
    }

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function joined()
    {
        //@todo change query to show groups joined
        // $groups = Group::where('created_by_user_id', auth()->id())->get();
        // $groups = Group::with('joinedUsers')

        $groups = auth()->user()->groupsJoined()->get();

        return view('groups/joined', compact('groups'));
    }

    /**
     * Show the form for creating a new resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function create()
    {
        return view('groups.create');
    }

    /**
     * Store a newly created resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request)

    {
        $request->validate([
            'group_title' => 'required',
            'group_description' => 'required',
            'group_date' => 'required',
            'group_time' => 'required',
        ]);

        $group = new Group([
            'group_title' => $request->get('group_title'),
            'group_description' => $request->get('group_description'),
            'group_date' => $request->get('group_date'),
            'group_time' => $request->get('group_time'),
        ]);
        $group->save();
        return redirect('/groups')->with('success', 'Group saved!!');
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function show($id)
    {
        // $group = Group::find($id);
        $group = Group::with('createdByUser')->where('id', $id)->first();
        return view('groups.show', compact('group'));
    }

    /**
     * Show the form for editing the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function edit($id)
    {
        $group = Group::find($id);
        return view('groups.edit', compact('group'));
    }

    /**
     * Update the specified resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function update(Request $request, $id)
    {
        $request->validate([
            'group_title' => 'required',
            'group_description' => 'required',
            'group_date' => 'required',
            'group_time' => 'required',
        ]);

        $group = Group::find($id);
        $group->group_title =  $request->get('group_title');
        $group->group_description = $request->get('group_description');
        $group->group_date = $request->get('group_date');
        $group->group_time = $request->get('group_time');
        $group->save();
        return redirect('/groups')->with('success', 'Group updated!');
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function destroy($id)
    {
        $group = Group::find($id);
        $group->delete();
        return redirect('/groups')->with('success', 'Group deleted!');
    }
}

但错误在于：

未定义变量：groupCreated

---

有什么帮助吗？

问题可能是

@if（$groupCreated（））

。这条线应该做什么

---

如果您只想检查用户是否有任何组，您可以使用

@If（$user->groupsCreated->count（）>0）

错误来自哪一行和文件？您将返回到视图中的

@if else

语句是什么？您的任何控制器方法都不会将

$user

发送到视图。我应该将用户发送到哪个视图？

@if ($groupCreated())

<small id="emailHelp" class="form-text text-muted pb-3">Deleted groups are not shown</small>
@foreach($user->groupsCreated as $groupCreated)
<div class="alert alert-success" role="alert">
<a href="{{ route('groups.show',$groupCreated->id)}}"> {{ ucwords(trans($groupCreated->group_title)) }}</a>
</div>
@endforeach

@else

<!-- Show if no groups created -->
<!-- <small id="emailHelp" class="form-text text-muted pb-3">Deleted groups are not shown</small>
<div class="alert alert-secondary" role="alert">
This user has no active groups</div> -->

@endif

<?php

namespace App\Http\Controllers;

use App\Group;
use Illuminate\Http\Request;

// All Groups pages require login except 'show'
class GroupsController extends Controller
{

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

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function index()
    {
        $groups = Group::where('created_by_user_id', auth()->id())->get();

        return view('groups/index', compact('groups'));
    }

    /**
     * Store the group that a user has joined in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function join(Request $request)
    {
        $request->validate([
            'group_id' => 'required',
        ]);

        $user_id = auth()->id();
        $group = Group::find($request->get('group_id'));

        if (!$group->isLoggedInUserJoined())
            $group->joinedUsers()->attach($user_id);

        $redirect = $request->get('redirect', 'groups/joined');

        return redirect($redirect)->with('success', 'You joined the group!!');
    }

    /**
     * Remove the user from a group that they have joined in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function unjoin(Request $request)
    {
        $request->validate([
            'group_id' => 'required',
        ]);

        $group = Group::find($request->get('group_id'));

        if ($group->isLoggedInUserJoined())
            $group->joinedUsers()->detach(auth()->id());

        $redirect = $request->get('redirect', 'groups/joined');

        return redirect($redirect)->with('success', 'You\'ve left the group.');
    }

    /**
     * Display a listing of the resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function joined()
    {
        //@todo change query to show groups joined
        // $groups = Group::where('created_by_user_id', auth()->id())->get();
        // $groups = Group::with('joinedUsers')

        $groups = auth()->user()->groupsJoined()->get();

        return view('groups/joined', compact('groups'));
    }

    /**
     * Show the form for creating a new resource.
     *
     * @return \Illuminate\Http\Response
     */
    public function create()
    {
        return view('groups.create');
    }

    /**
     * Store a newly created resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\Response
     */
    public function store(Request $request)

    {
        $request->validate([
            'group_title' => 'required',
            'group_description' => 'required',
            'group_date' => 'required',
            'group_time' => 'required',
        ]);

        $group = new Group([
            'group_title' => $request->get('group_title'),
            'group_description' => $request->get('group_description'),
            'group_date' => $request->get('group_date'),
            'group_time' => $request->get('group_time'),
        ]);
        $group->save();
        return redirect('/groups')->with('success', 'Group saved!!');
    }

    /**
     * Display the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function show($id)
    {
        // $group = Group::find($id);
        $group = Group::with('createdByUser')->where('id', $id)->first();
        return view('groups.show', compact('group'));
    }

    /**
     * Show the form for editing the specified resource.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function edit($id)
    {
        $group = Group::find($id);
        return view('groups.edit', compact('group'));
    }

    /**
     * Update the specified resource in storage.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function update(Request $request, $id)
    {
        $request->validate([
            'group_title' => 'required',
            'group_description' => 'required',
            'group_date' => 'required',
            'group_time' => 'required',
        ]);

        $group = Group::find($id);
        $group->group_title =  $request->get('group_title');
        $group->group_description = $request->get('group_description');
        $group->group_date = $request->get('group_date');
        $group->group_time = $request->get('group_time');
        $group->save();
        return redirect('/groups')->with('success', 'Group updated!');
    }

    /**
     * Remove the specified resource from storage.
     *
     * @param  int  $id
     * @return \Illuminate\Http\Response
     */
    public function destroy($id)
    {
        $group = Group::find($id);
        $group->delete();
        return redirect('/groups')->with('success', 'Group deleted!');
    }
}

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Group extends Model
{
    protected $fillable = [
        'group_title',
        'group_description',
        'group_date',
        'group_time',
        'created_by_user_id'
    ];

    public static function boot()
    {
        parent::boot();

        static::creating(function ($group) {
            $group->created_by_user_id = auth()->id();
        });
    }

    /**
     * Get the user that created the group.
     */
    public function createdByUser()
    {
        return $this->belongsTo(User::class, 'created_by_user_id');
    }
    /**
     * Get the users that joined the group.
     */
    public function joinedUsers()
    {
        return $this->belongsToMany(User::class, 'group_joined_user', 'group_id', 'user_id')
            ->withTimestamps();
    }
    /**
     * Checks whether the currently logged in user is joined to the group.
     */
    public function isLoggedInUserJoined()
    {
        return $this->joinedUsers()->where('users.id', auth()->id())->exists();
    }
}

  /**
     * Fetch the groups created by user
     */
    public function groupCreated()
    {
        return $this->groupCreated()->where('groups.show', auth()->id());
    }