Question

我正在创建一个包含两种类型对象的流，BluePerson和RedPerson。要创建流，我将获取所有两个对象，然后将它们合并到一个集合中。在这样做之后，我需要对它们进行分页，但是paginate用于雄辩的模型和数据库查询，而不是集合。我已经看到很多关于手动创建分页器的内容，但是文档，尤其是API中的文档很稀疏（我甚至无法找到Paginator类接受的参数。）

如何对合并我的馆藏的结果进行分页？

public function index()
{
    $bluePerson = BluePerson::all();
    $redPerson = RedPerson::all();

    $people = $bluePerson->merge($redPerson)->sortByDesc('created_at');


    return view('stream.index')->with('people', $people);
}

Answer 1

如果您想使用LengthAwarePaginator，只需实例化一个。如前一个答案的评论中所述，您必须为此设置路径。您还需要确保解析“currentPage”并在实例化分页器之前设置要返回的项目。这可以在实例化之前/之后完成。所以函数可能看起来像：

function paginateCollection($collection, $perPage, $pageName = 'page', $fragment = null)
{
    $currentPage = \Illuminate\Pagination\LengthAwarePaginator::resolveCurrentPage($pageName);
    $currentPageItems = $collection->slice(($currentPage - 1) * $perPage, $perPage);
    parse_str(request()->getQueryString(), $query);
    unset($query[$pageName]);
    $paginator = new \Illuminate\Pagination\LengthAwarePaginator(
        $currentPageItems,
        $collection->count(),
        $perPage,
        $currentPage,
        [
            'pageName' => $pageName,
            'path' => \Illuminate\Pagination\LengthAwarePaginator::resolveCurrentPath(),
            'query' => $query,
            'fragment' => $fragment
        ]
    );

    return $paginator;
}

Answer 2

然而，paginate用于雄辩的模型和数据库查询，而不是集合，似乎。

你是对的。但是对于集合有一个分页器功能。 forPage

语法：

Collection forPage(int $page, int $perPage)

实施例

休息很简单。

public function foo()
{
    $collection = collect([1,2,3,4,5,6,7,8,9,0]);
    $items = $collection->forPage($_GET['page'], 5); //Filter the page var
    dd($items);
}

Answer 3

您可以尝试对两个集进行分页并合并它们。您可以在docs和api中找到有关分页的更多信息。以下是手动创建自己的分页器的示例...

$perPage = 20;
$blue = BluePerson::paginate($perPage / 2);
$red = RedPerson::paginate($perPage - count($blue));
$people = PaginationMerger::merge($blue, $red);

我在下面包含了PaginationMerger类。

use Illuminate\Pagination\LengthAwarePaginator;

class PaginationMerger
{
    /**
     * Merges two pagination instances
     *
     * @param  Illuminate\Pagination\LengthAwarePaginator $collection1
     * @param  Illuminate\Pagination\LengthAwarePaginator $collection2
     * @return Illuminate\Pagination\LengthAwarePaginator
     */
    static public function merge(LengthAwarePaginator $collection1, LengthAwarePaginator $collection2)
    {
        $total = $collection1->total() + $collection2->total();

        $perPage = $collection1->perPage() + $collection2->perPage();

        $items = array_merge($collection1->items(), $collection2->items());

        $paginator = new LengthAwarePaginator($items, $total, $perPage);

        return $paginator;
    }
}

Answer 4

您可以在 Providers / AppServiceProvider 中为Collection添加以下代码。

    // Enable pagination
    if (!Collection::hasMacro('paginate')) {

        Collection::macro('paginate', 
            function ($perPage = 15, $page = null, $options = []) {
            $page = $page ?: (Paginator::resolveCurrentPage() ?: 1);
            return (new LengthAwarePaginator(
                $this->forPage($page, $perPage)->values()->all(), $this->count(), $perPage, $page, $options))
                ->withPath('');
        });
    }

然后，您可以像Eloquent模型一样从集合中调用分页。例如

$pages = collect([1, 2, 3, 4, 5, 6, 7, 8, 9])->paginate(5);

Answer 5

尝试以下操作。

img {
    position: absolute;
    top: (-$item-height / 2) + ($item-width / 2);
}

Answer 6

分页收集的最佳方法：

1-将其添加到\ app \ Providers \ AppServiceProvider的启动功能

       /*
         * use Illuminate\Support\Collection;
         * use Illuminate\Pagination\LengthAwarePaginator;
         *
         * Paginate a standard Laravel Collection.
         *
         * @param int $perPage
         * @param int $total
         * @param int $page
         * @param string $pageName
         * @return array
         */
        Collection::macro('paginate', function($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,
                ]
            );
        });

2-从此以后，您可以对所有集合进行分页，就像您的代码一样

$people->paginate(5)

Answer 7

我必须在一个正在处理的项目中处理类似的问题，在其中的一个页面中，我必须显示两种类型的出版物：分页和< strong> 按 created_at 字段排序。在我的情况下，这是一个 Post 模型和一个 Event 模型（以下称为出版物 ）。 >

唯一的区别是，我不想从数据库中获取所有出版物，然后合并并对结果进行排序，因为您可以想象，如果我们有数百个出版物，这将引发性能问题。

因此，我发现对每个模型进行分页，然后进行合并和排序会更加方便。

这就是我所做的（基于先前发布的答案和评论）

首先让我向您展示“我的解决方案”的简化版本，然后我将尽我所能解释代码。

use App\Models\Post;
use App\Models\Event;
use App\Facades\Paginator;


class PublicationsController extends Controller
{
    /**
     * Display a listing of the resource.
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Http\Response
     */
    public function index(Request $request)
    {
        $events       = Event::latest()->paginate(5);
        $posts        = Post::latest()->paginate(5);

        $publications = Paginator::merge($events, $posts)->sortByDesc('created_at')->get();

        return view('publications.index', compact('publications'));
    }
}

您可能已经猜到了， 外表分页器 负责对我的分页器进行合并和排序（$events和$posts）

为了使这个答案更加清晰和完整，我将向您展示如何创建自己的Facade。

您可以选择将自己的外墙放置在您喜欢的任何位置，就像我在树中所示，我个人选择将它们放置在app文件夹下的Facades文件夹内。

+---app
|   +---Console
|   +---Events
|   +---Exceptions
|   +---Exports
|   +---Facades
|   |   +---Paginator.php
|   |   +---...
|   +---Http
|   |   +---Controllers
.   .   +---...
.   .   .

将此代码放入app/Facades/Paginator.php

namespace App\Facades;

use Illuminate\Support\Facades\Facade;

class Paginator extends Facade
{
    /**
     * Get the registered name of the component.
     *
     * @return string
     */
    protected static function getFacadeAccessor()
    {
        return 'paginator';
    }
}

有关更多信息，请参阅How Facades Work

接下来，绑定分页器到服务容器，打开app\Providers\AppServiceProvider.php

namespace App\Providers;

use App\Services\Pagination\Paginator;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        $this->app->bind('paginator', function ($app) {

            return new Paginator;
        });
    }
}

有关更多信息，请参阅The Boot Method

我的Paginator类位于app/Services/Pagination/文件夹下。同样，您可以将您的课堂放在任何喜欢的地方。

namespace App\Services\Pagination;

use Illuminate\Support\Arr;
use InvalidArgumentException;
use Illuminate\Support\Collection;
use Illuminate\Pagination\LengthAwarePaginator;

class Paginator
{
    /**
     * All of the items being paginated.
     *
     * @var \Illuminate\Support\Collection
     */
    protected $items;

    /**
     * The number of items to be shown per page.
     *
     * @var int
     */
    protected $perPage;

    /**
     * The total number of items before slicing.
     *
     * @var int
     */
    protected $total;

    /**
     * The base path to assign to all URLs.
     *
     * @var string
     */
    protected $path = '/';


    /**
     * Merge paginator instances
     *
     * @param  mixed $paginators
     * @param  bool  $descending
     * @return \Illuminate\Pagination\LengthAwarePaginator
     */
    function merge($paginators)
    {
        $paginators = is_array($paginators) ? $paginators : func_get_args();

        foreach ($paginators as $paginator) {
            if (!$paginator instanceof LengthAwarePaginator) {
                throw new InvalidArgumentException("Only LengthAwarePaginator may be merged.");
            }
        }

        $total   = array_reduce($paginators, function($carry, $paginator) {

            return $paginator->total();
        }, 0);

        $perPage = array_reduce($paginators, function($carry, $paginator) {

            return $paginator->perPage();
        }, 0);

        $items   = array_map(function($paginator) {

            return $paginator->items();

        }, $paginators);

        $items         = Arr::flatten($items);

        $items         = Collection::make($items);

        $this->items   = $items;
        $this->perPage = $perPage;
        $this->total   = $total;

        return $this;
    }

    /**
     * Sort the collection using the given callback.
     *
     * @param  callable|string  $callback
     * @param  int  $options
     * @param  bool  $descending
     * @return static
     */
    public function sortBy($callback, $options = SORT_REGULAR, $descending = false)
    {
        $this->items = $this->items->sortBy($callback, $options, $descending);

        return $this;
    }

    /**
     * Sort the collection in descending order using the given callback.
     *
     * @param  callable|string  $callback
     * @param  int  $options
     * @return static
     */
    public function sortByDesc($callback, $options = SORT_REGULAR)
    {
        return $this->sortBy($callback, $options, true);
    }

    /**
     * Get paginator
     *
     * @return \Illuminate\Pagination\LengthAwarePaginator
     */
    public function get()
    {
        return new LengthAwarePaginator(
            $this->items,
            $this->total,
            $this->perPage,
            LengthAwarePaginator::resolveCurrentPage(),
            [
                'path' => LengthAwarePaginator::resolveCurrentPath(),
            ]
        );
    }
}

肯定有改进的空间，因此，如果您发现需要更改的地方，请在此处发表评论或通过twitter与我联系。

Answer 8

你可以像下面这样改变它：

public function index()
{
    $bluePerson = BluePerson::paginate();
    $redPerson = RedPerson::all();

    $people = $bluePerson->merge($redPerson)->sortByDesc('created_at');


    return view('stream.index')->with('people', $people);
}

如何在Laravel 5中对合并的集合进行分页？

8 个答案:

语法：

实施例