Detailed explanation of manual paging implementation method in Laravel

The example in this article describes the implementation method of manual paging in Laravel. Share it with everyone for your reference, the details are as follows:

The demonstration example here is based on Laravel version 5.2

There is a situation during the development process, you request the Java api to obtain information, because the information There are many and need to be displayed in pages. Laravel officially provides a simple method, paginate($perPage), but this method only applies to model and query builder.

Today I will talk about how to achieve the same effect as the paginate method given an array.

View the source code of paginate method

#vendor/laravel/framework/src/Illuminate/Database/Eloquent/Builder.php:480
public function paginate($perPage = null, $columns = ['*'], $pageName = 'page', $page = null)
{
    $query = $this->toBase();
    $total = $query->getCountForPagination();
    $this->forPage(
      $page = $page ?: Paginator::resolveCurrentPage($pageName),
      $perPage = $perPage ?: $this->model->getPerPage()
    );
    return new LengthAwarePaginator($this->get($columns), $total, $perPage, $page, [
      'path' => Paginator::resolveCurrentPath(),
      'pageName' => $pageName,
    ]);
}

As you can see from the above, the key to paging lies in LengthAwarePaginator.

Construction method of LengthAwarePaginator.

public function __construct($items, $total, $perPage, $currentPage = null, array $options = [])
{
    foreach ($options as $key => $value) {
      $this->{$key} = $value;
    }
    $this->total = $total;
    $this->perPage = $perPage;
    $this->lastPage = (int) ceil($total / $perPage);
    $this->path = $this->path != '/' ? rtrim($this->path, '/') : $this->path;
    $this->currentPage = $this->setCurrentPage($currentPage, $this->lastPage);
    $this->items = $items instanceof Collection ? $items : Collection::make($items);
}

In fact, it is already very clear. If the array to be paged is

[
  ['username'=>'zhangsan', 'age'=>26],
  ['username'=>'lisi', 'age'=>23],
  ['username'=>'wangwu', 'age'=>62],
  ['username'=>'zhaoliu', 'age'=>46],
  ['username'=>'wangmazi', 'age'=>25],
  ['username'=>'lanzi', 'age'=>24],
  ['username'=>'pangzi', 'age'=>21],
]

, a total of 7 pieces of data, each page will display 3 pieces, a total of 3 pages.

use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Pagination\Paginator;
use Illuminate\Http\Request;
# 仅做演示 #
function userList(Request $request) {
  $users = [
    ['username'=>'zhangsan', 'age'=>26],
    ['username'=>'lisi', 'age'=>23],
    ['username'=>'wangwu', 'age'=>62],
    ['username'=>'zhaoliu', 'age'=>46],
    ['username'=>'wangmazi', 'age'=>25],
    ['username'=>'lanzi', 'age'=>24],
    ['username'=>'pangzi', 'age'=>21]
  ];
  $perPage = 3;
  if ($request->has('page')) {
      $current_page = $request->input('page');
      $current_page = $current_page <= 0 ? 1 :$current_page;
  } else {
      $current_page = 1;
  }
  $item = array_slice($users, ($current_page-1)*$perPage, $perPage); //注释1
  $total = count($users);
  $paginator =new LengthAwarePaginator($item, $total, $perPage, $currentPage, [
      &#39;path&#39; => Paginator::resolveCurrentPath(), //注释2
      &#39;pageName&#39; => &#39;page&#39;,
  ]);
  $userlist = $paginator->toArray()[&#39;data&#39;];
  return view(&#39;userlist&#39;, compact(&#39;userlist&#39;, &#39;paginator&#39;));
}

The above code The key point is $item. If comment 1 is not processed, all 7 pieces of data will be obtained.

Note 2 is to set a url address to be paginated. It can also be set manually through $paginator ->setPath('path').

The paging connection in the page is also called in the same way:

{{ $paginator->render() }}

Okay, that’s basically it. If there are any mistakes, please correct me!

I hope this article will be helpful to everyone’s PHP program design based on the Laravel framework.

For more detailed explanations of Laravel manual paging implementation methods and related articles, please pay attention to the PHP Chinese website!