如何对 Laravel 集合进行分页？

Question

这是我尝试分页的方式：

$posts = Post::all()->sortByDesc("created_at")->pagination(1);

但我收到此错误：

方法 Illuminate\Database\Eloquent\Collection::pagination 不存在。

Answer 1

创建助手类

<?php

namespace App\Helpers;

use Illuminate\Container\Container;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Pagination\Paginator;
use Illuminate\Support\Collection;

class PaginationHelper
{
    public static function paginate(Collection $results, $showPerPage)
    {
        $pageNumber = Paginator::resolveCurrentPage('page');
        
        $totalPageNumber = $results->count();

        return self::paginator($results->forPage($pageNumber, $showPerPage), $totalPageNumber, $showPerPage, $pageNumber, [
            'path' => Paginator::resolveCurrentPath(),
            'pageName' => 'page',
        ]);

    }

    /**
     * Create a new length-aware paginator instance.
     *
     * @param  \Illuminate\Support\Collection  $items
     * @param  int  $total
     * @param  int  $perPage
     * @param  int  $currentPage
     * @param  array  $options
     * @return \Illuminate\Pagination\LengthAwarePaginator
     */
    protected static function paginator($items, $total, $perPage, $currentPage, $options)
    {
        return Container::getInstance()->makeWith(LengthAwarePaginator::class, compact(
            'items', 'total', 'perPage', 'currentPage', 'options'
        ));
    }
}

要添加辅助文件后打开composer.json文件，composer有一个文件键（这是一个文件路径数组），您可以在自动加载内部定义它

"autoload": {
    "files": [
        "app/Helpers/PaginationHelper.php"
    ],
    "classmap": [
        "database/seeds",
        "database/factories"
    ],
    "psr-4": {
        "App\\": "app/"
    }
},

现在你必须在终端中输入此命令

composer dump-autoload

现在您可以创建集合分页，如下例所示

Route::get('/test_collect_pagintae', function () {

    $users = \App\User::get();

    $showPerPage = 20;

    $paginated = PaginationHelper::paginate($users, $showPerPage);

    return $paginated;
});

Answer 2

因为

paginate

是

Builder

方法，而不是集合。

您需要手动创建分页器，具体描述如下 - https://laravel.com/docs/8.x/pagination#manually-creating-a-paginator

Answer 3

您可以在 boot 方法中的

app/provider/serviceProvider

中使用此代码

Collection::macro('paginate', function($perPage, $page = null, $pageName = 'page') {
            $page = $page ?: LengthAwarePaginator::resolveCurrentPage($pageName);
            return new LengthAwarePaginator(
                $this->forPage($page, $perPage), // $items
                $this->count(),                  // $total
                $perPage,
                $page,
                [                                // $options
                    'path' => LengthAwarePaginator::resolveCurrentPath(),
                    'pageName' => $pageName,
                ]
            );
        });

Answer 4

解决方案

这是 simonhamp 提供的非常好的解决方案，谢谢 simonhamp

我的建议是在 AppServiceProvider 中执行 ->values() ，如下所示。这很重要，因为当切片集合时，键被保留，我们不希望分页器这样做。

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

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

Answer 5

您可以通过删除所有内容轻松分页：-

$posts = Post::sortByDesc("created_at")->pagination(1);

就我而言，我必须合并多个集合，然后对合并的数据进行分页，因此我必须执行以下操作：-

$items = $items2->merge($items1);
$items = $this->paginate($items);

public function paginate($items, $perPage = 15, $page = null, $options = [])
{
    $page = $page ?: (Paginator::resolveCurrentPage() ?: 1);
    $items = $items instanceof Collection ? $items : Collection::make($items);
    return new LengthAwarePaginator($items->forPage($page, $perPage), $items->count(), $perPage, $page, $options);
}

参考：- Laravel 文档， 如何对 Laravel 集合进行分页？

Answer 6

试试这个代码：

//convert to array
$posts = Post::all()->sortByDesc("created_at")->toArray();

//Create new pagination
$currentPage = LengthAwarePaginator::resolveCurrentPage();
$perPage = 3;
$currentItems = array_slice($posts, $perPage * ($currentPage - 1), $perPage);
//with path of current page
$posts = (new LengthAwarePaginator($currentItems, count($posts ), $perPage, $currentPage))->setPath(route('posts....'));

//Convert array of array to array of object
$posts->each(function ($item, $itemKey) use($posts) {
     $posts[$itemKey] = (Object)$item;
});