数据分页

当有一大组数据需要呈现时，我们需要用到数据分页。Phalcon\Paginator 提供了一个快捷，方便的方法对大组数据进行分割，以达到分页浏览的效果。

Data Adapters

这个组件使用不同的适配器来封装不同的数据源：

Adapter	Description
NativeArray	Use a PHP array as source data
Model	Use a Phalcon\Model\Resultset object as source data

Using Paginators

在下面的例子中，paginator将从model中读取数据作为其数据源，并限制每页显示10条记录：

<?php

// Current page to show
// In a controller 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 Phalcon\Paginator\Adapter\Model(
    array(
        "data" => $robots,
        "limit"=> 10,
        "page" => $currentPage
    )
);

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

变量 $currentPage 控制将显示哪一页。 $paginator->getPaginate() 返回一个包含分页数据的 $page 对象，它将用于生成分页：

<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>

$page对象还包含以下数据：

<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; ?>

Page 属性

$page对象包含以下一些属性：

Adapter	Description
items	The set of records to be displayed at 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

实现自定义的分页适配器

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

<?php

class MyPaginator implements Phalcon\Paginator\AdapterInterface  {

    /**
     * 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();

}