Laravel手动分页实现方法详解
author:一佰互联 2019-04-26   click:219

本文实例讲述了Laravel手动分页实现方法。分享给大家供大家参考,具体如下:

这里的演示实例基于Laravel的5.2版本

在开发过程中有这么一种情况,你请求Java api获取信息,由于信息较多,需要分页显示。Laravel官方提供了一个简单的方式paginate($perPage),但是这种方法只适用model、查询构建器。

今天说下 给定一个数组如何实现 和paginate方法一样的效果。

查看paginate方法源码

#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,
    ]);
}

从上面就可以看出,分页的关键就在于LengthAwarePaginator。

LengthAwarePaginator的构造方法。

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);
}

其实已经很明白了,假如要分页的数组为

[
  ["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],
]

共7条数据,每页显示3条,共3页

use IlluminatePaginationLengthAwarePaginator;
use IlluminatePaginationPaginator;
use IlluminateHttpRequest;
# 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, [
      "path" => Paginator::resolveCurrentPath(), //注释2
      "pageName" => "page",
  ]);
  $userlist = $paginator->toArray()["data"];
  return view("userlist", compact("userlist", "paginator"));
}

上面的代码中的重点是$item,如果不做注释1处理,得出的是所有7条数据。

注释2处就是设定个要分页的url地址。也可以手动通过 $paginator ->setPath("路径") 设置。

页面中的分页连接也是同样的调用方式:

{{ $paginator->render() }}

好了,基本就是这样,有纰漏的地方欢迎指正!

看看最终效果:

更多关于Laravel相关内容感兴趣的读者可查看本站专题:《Laravel框架入门与进阶教程》、《php优秀开发框架总结》、《smarty模板入门基础教程》、《php日期与时间用法总结》、《php面向对象程序设计入门教程》、《php字符串(string)用法总结》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》

希望本文所述对大家基于Laravel框架的PHP程序设计有所帮助。