Same name in other branches

1. 7.x includes/pager.inc \pager_default_initialize()

Initializes a pager.

This function sets up the necessary global variables so that the render system will correctly process #type 'pager' render arrays to output pagers that correspond to the items being displayed.

If the items being displayed result from a database query performed using Drupal's database API, and if you have control over the construction of the database query, you do not need to call this function directly; instead, you can simply extend the query object with the 'PagerSelectExtender' extender before executing it. For example:

$query = \Drupal::database()->select('some_table')
    ->extend('Drupal\\Core\\Database\\Query\\PagerSelectExtender');

However, if you are using a different method for generating the items to be paged through, then you should call this function in preparation.

The following example shows how this function can be used in a controller that invokes an external datastore with an SQL-like syntax:

// First find the total number of items and initialize the pager.
$where = "status = 1";
$total = mymodule_select("SELECT COUNT(*) FROM data " . $where)->result();
$num_per_page = \Drupal::config('mymodule.settings')->get('num_per_page');
$page = pager_default_initialize($total, $num_per_page);
// Next, retrieve the items for the current page and put them into a
// render array.
$offset = $num_per_page * $page;
$result = mymodule_select("SELECT * FROM data " . $where . " LIMIT %d, %d", $offset, $num_per_page)->fetchAll();
$render = [];
$render[] = [
    '#theme' => 'mymodule_results',
    '#result' => $result,
];
// Finally, add the pager to the render array, and return.
$render[] = [
    '#type' => 'pager',
];
return $render;

A second example involves a controller that invokes an external search service where the total number of matching results is provided as part of the returned set (so that we do not need a separate query in order to obtain this information). Here, we call pager_find_page() to calculate the desired offset before the search is invoked:

// Perform the query, using the requested offset from pager_find_page().
// This comes from a URL parameter, so here we are assuming that the URL
// parameter corresponds to an actual page of results that will exist
// within the set.
$page = pager_find_page();
$num_per_page = \Drupal::config('mymodule.settings')->get('num_per_page');
$offset = $num_per_page * $page;
$result = mymodule_remote_search($keywords, $offset, $num_per_page);
// Now that we have the total number of results, initialize the pager.
pager_default_initialize($result->total, $num_per_page);
// Create a render array with the search results.
$render = [];
$render[] = [
    '#theme' => 'search_results',
    '#results' => $result->data,
    '#type' => 'remote',
];
// Finally, add the pager to the render array, and return.
$render[] = [
    '#type' => 'pager',
];
return $render;

Parameters

int $total: The total number of items to be paged.

int $limit: The number of items the calling code will display per page.

int $element: (optional) An integer to distinguish between multiple pagers on one page.

Return value

int The number of the current page, within the pager represented by $element. This is determined from the URL query parameter \Drupal::request()->query->get('page), or 0 by default. However, if a page that does not correspond to the actual range of the result set was requested, this function will return the closest page actually within the result set.

See also

https://www.drupal.org/node/2779457

\Drupal\Core\Pager\PagerManagerInterface::createPager()

1 call to pager_default_initialize()

PagerDeprecationTest::testDefaultInitialize in core/modules/system/tests/src/Kernel/Pager/PagerDeprecationTest.php

@expectedDeprecation pager_default_initialize is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Use \Drupal\Core\Pager\PagerManagerInterface->createPager() instead. See https://www.drupal.org/node/2779457

File

core/includes/pager.inc, line 137

Code

function pager_default_initialize($total, $limit, $element = 0) {
    @trigger_error(__FUNCTION__ . ' is deprecated in drupal:8.8.0 and is removed from drupal:9.0.0. Use \\Drupal\\Core\\Pager\\PagerManagerInterface->createPager() instead. See https://www.drupal.org/node/2779457', E_USER_DEPRECATED);
    
    /* @var $pager_manager \Drupal\Core\Pager\PagerManagerInterface */
    $pager_manager = \Drupal::service('pager.manager');
    $pager = $pager_manager->createPager($total, $limit, $element);
    return $pager->getCurrentPage();
}

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