分页(Pagination)

最后更新于:2018-09-01 07:08:51

The process of pagination takes place when we need to present big groups of arbitrary data gradually. Phalcon\Paginator offers a
fast and convenient way to split these sets of data into browsable pages.

数据适配器(Data Adapters)

This component makes use of adapters to encapsulate different sources of data:

Adapter Description
Phalcon\Paginator\Adapter\NativeArray Use a PHP array as source data
Phalcon\Paginator\Adapter\Model Use a Phalcon\Mvc\Model\Resultset object as source data. Since PDO doesn’t support scrollable cursors this adapter shouldn’t be used to paginate a large number of records
Phalcon\Paginator\Adapter\QueryBuilder Use a Phalcon\Mvc\Model\Query\Builder object as source data

示例(Examples)

In the example below, the paginator will use the result of a query from a model as its source data, and limit the displayed data to 10 records per page:

<?php

use Phalcon\Paginator\Adapter\Model as PaginatorModel;

// Current page to show
// In a controller/component this can be:
// $this->request->getQuery("page", "int"); // GET
// $this->request->getPost("page", "int"); // POST
$currentPage = (int) $_GET["page"];

// The data set to paginate
$robots = Robots::find();

// Create a Model paginator, show 10 rows by page starting from $currentPage
$paginator = new PaginatorModel(
    [
        "data"  => $robots,
        "limit" => 10,
        "page"  => $currentPage,
    ]
);

// Get the paginated results
$page = $paginator->getPaginate();

The $currentPage variable controls the page to be displayed. The $paginator->getPaginate() returns a $page
object that contains the paginated data. It can be used for generating the pagination:

<table>
    <tr>
        <th>Id</th>
        <th>Name</th>
        <th>Type</th>
    </tr>
    <?php foreach ($page->items as $item) { ?>
    <tr>
        <td><?php echo $item->id; ?></td>
        <td><?php echo $item->name; ?></td>
        <td><?php echo $item->type; ?></td>
    </tr>
    <?php } ?>
</table>

The $page object also contains navigation data:

<a href="/robots/search">First</a>
<a href="/robots/search?page=<?= $page->before; ?>">Previous</a>
<a href="/robots/search?page=<?= $page->next; ?>">Next</a>
<a href="/robots/search?page=<?= $page->last; ?>">Last</a>

<?php echo "You are in page ", $page->current, " of ", $page->total_pages; ?>

适配器使用(Adapters Usage)

An example of the source data that must be used for each adapter:

<?php

use Phalcon\Paginator\Adapter\Model as PaginatorModel;
use Phalcon\Paginator\Adapter\NativeArray as PaginatorArray;
use Phalcon\Paginator\Adapter\QueryBuilder as PaginatorQueryBuilder;

// Passing a resultset as data
$paginator = new PaginatorModel(
    [
        "data"  => Products::find(),
        "limit" => 10,
        "page"  => $currentPage,
    ]
);

// Passing an array as data
$paginator = new PaginatorArray(
    [
        "data"  => [
            ["id" => 1, "name" => "Artichoke"],
            ["id" => 2, "name" => "Carrots"],
            ["id" => 3, "name" => "Beet"],
            ["id" => 4, "name" => "Lettuce"],
            ["id" => 5, "name" => ""],
        ],
        "limit" => 2,
        "page"  => $currentPage,
    ]
);

// Passing a QueryBuilder as data

$builder = $this->modelsManager->createBuilder()
    ->columns("id, name")
    ->from("Robots")
    ->orderBy("name");

$paginator = new PaginatorQueryBuilder(
    [
        "builder" => $builder,
        "limit"   => 20,
        "page"    => 1,
    ]
);

页面属性(Page Attributes)

The $page object has the following attributes:

Attribute Description
items The set of records to be displayed at the current page
current The current page
before The previous page to the current one
next The next page to the current one
last The last page in the set of records
total_pages The number of pages
total_items The number of items in the source data

自定义适配器(Implementing your own adapters)

The Phalcon\Paginator\AdapterInterface interface must be implemented in order to create your own paginator adapters or extend the existing ones:

<?php

use Phalcon\Paginator\AdapterInterface as PaginatorInterface;

class MyPaginator implements PaginatorInterface
{
    /**
     * Adapter constructor
     *
     * @param array $config
     */
    public function __construct($config);

    /**
     * Set the current page number
     *
     * @param int $page
     */
    public function setCurrentPage($page);

    /**
     * Returns a slice of the resultset to show in the pagination
     *
     * @return stdClass
     */
    public function getPaginate();
}