laravel - 为集合分页，Laravel

Question

我尝试从 foreach 向每个用户添加一些新值，但因为我使用 get，现在我不能在响应中使用分页，但我还需要向每个用户添加这些值。有什么想法吗？

public function statistics()
    {
        $users = User::select(['id', 'name'])->get();
        foreach ($users as $key => $user) {
            $history = AnswerHistory::where('user_id', '=', $user->id)->get();
            $user->total_votes = count($history);
            $user->total_time = gmdate("H:i:s", ($history->sum('answer_time')));
        }

        return response()->json($users);
    }

Answer 1

默认情况下，laravel 无法满足您的需求，但是您可以做一些事情。

方案一可以先返回paginator，再修改collection。

    $users = User::select(['id', 'name'])->paginate(4)->toArray();

    $users['data'] = array_map(function ($user) {
            $history = AnswerHistory::where('user_id', '=', $user->id)->get();
            $user->total_votes = count($history);
            $user->total_time = gmdate("H:i:s", ($history->sum('answer_time')));
        return $user;
    }, $users['data']);

    return  $users;

解决方法二 宏方式。如果您愿意，可以将 Collection 宏添加到服务提供者。这样你就可以在任何集合上调用 paginate() :有关示例实现，请参阅 AppServiceProvider.php。

    public function boot()
    {
        Collection::macro('paginate', function ($perPage, $total = null, $page = null, $pageName = 'page') {
            $page = $page ?: LengthAwarePaginator::resolveCurrentPage($pageName);

            return new LengthAwarePaginator(
                $this->forPage($page, $perPage),
                $total ?: $this->count(),
                $perPage,
                $page,
                [
                    'path' => LengthAwarePaginator::resolveCurrentPath(),
                    'pageName' => $pageName,
                ]
            );
        });
    }

然后你的代码会是这样

        $users = User::select(['id', 'name'])->get();
        foreach ($users as $key => $user) {
            $history = AnswerHistory::where('user_id', '=', $user->id)->get();
            $user->total_votes = count($history);
            $user->total_time = gmdate("H:i:s", ($history->sum('answer_time')));
        }

        return response()->json($users->paginate(4));

解决方案三 子类方式。在您想要一个不同于标准 Illuminate\Support\Collection 的“可分页”集合的地方，在您的应用程序中实现一个 Collection.php 的副本并简单地替换您的 在依赖文件的顶部使用 Illuminate\Support\Collection 语句 use App\Support\Collection:

<?php

namespace App\Support;

use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Collection as BaseCollection;

class Collection extends BaseCollection
{
    public function paginate($perPage, $total = null, $page = null, $pageName = 'page')
    {
        $page = $page ?: LengthAwarePaginator::resolveCurrentPage($pageName);

        return new LengthAwarePaginator(
            $this->forPage($page, $perPage),
            $total ?: $this->count(),
            $perPage,
            $page,
            [
                'path' => LengthAwarePaginator::resolveCurrentPath(),
                'pageName' => $pageName,
            ]
        );
    }
}

你的代码将是这样的

// use Illuminate\Support\Collection
use App\Support\Collection;

        $users = User::select(['id', 'name'])->get();
        foreach ($users as $key => $user) {
            $history = AnswerHistory::where('user_id', '=', $user->id)->get();
            $user->total_votes = count($history);
            $user->total_time = gmdate("H:i:s", ($history->sum('answer_time')));
        }

        return response()->json((new Collection($users))->paginate(4);