PaginatorComponent.php

<?php
/**
 * CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
 * @link          https://cakephp.org CakePHP(tm) Project
 * @since         2.0.0
 * @license       https://opensource.org/licenses/mit-license.php MIT License
 */
namespace Cake\Controller\Component;

use Cake\Controller\Component;
use Cake\Controller\ComponentRegistry;
use Cake\Datasource\Exception\PageOutOfBoundsException;
use Cake\Datasource\Paginator;
use Cake\Network\Exception\NotFoundException;
use InvalidArgumentException;

/**
 * This component is used to handle automatic model data pagination. The primary way to use this
 * component is to call the paginate() method. There is a convenience wrapper on Controller as well.
 *
 * ### Configuring pagination
 *
 * You configure pagination when calling paginate(). See that method for more details.
 *
 * @link https://book.cakephp.org/3.0/en/controllers/components/pagination.html
 */
class PaginatorComponent extends Component
{

    /**
     * Default pagination settings.
     *
     * When calling paginate() these settings will be merged with the configuration
     * you provide.
     *
     * - `maxLimit` - The maximum limit users can choose to view. Defaults to 100
     * - `limit` - The initial number of items per page. Defaults to 20.
     * - `page` - The starting page, defaults to 1.
     * - `whitelist` - A list of parameters users are allowed to set using request
     *   parameters. Modifying this list will allow users to have more influence
     *   over pagination, be careful with what you permit.
     *
     * @var array
     */
    protected $_defaultConfig = [
        'page' => 1,
        'limit' => 20,
        'maxLimit' => 100,
        'whitelist' => ['limit', 'sort', 'page', 'direction']
    ];

    /**
     * Datasource paginator instance.
     *
     * @var \Cake\Datasource\Paginator
     */
    protected $_paginator;

    /**
     * {@inheritDoc}
     */
    public function __construct(ComponentRegistry $registry, array $config = [])
    {
        if (isset($config['paginator'])) {
            if (!$config['paginator'] instanceof Paginator) {
                throw new InvalidArgumentException('Paginator must be an instance of ' . Paginator::class);
            }
            $this->_paginator = $config['paginator'];
            unset($config['paginator']);
        } else {
            $this->_paginator = new Paginator();
        }

        parent::__construct($registry, $config);
    }

    /**
     * Events supported by this component.
     *
     * @return array
     */
    public function implementedEvents()
    {
        return [];
    }

    /**
     * Handles automatic pagination of model records.
     *
     * ### Configuring pagination
     *
     * When calling `paginate()` you can use the $settings parameter to pass in pagination settings.
     * These settings are used to build the queries made and control other pagination settings.
     *
     * If your settings contain a key with the current table's alias. The data inside that key will be used.
     * Otherwise the top level configuration will be used.
     *
     * ```
     *  $settings = [
     *    'limit' => 20,
     *    'maxLimit' => 100
     *  ];
     *  $results = $paginator->paginate($table, $settings);
     * ```
     *
     * The above settings will be used to paginate any Table. You can configure Table specific settings by
     * keying the settings with the Table alias.
     *
     * ```
     *  $settings = [
     *    'Articles' => [
     *      'limit' => 20,
     *      'maxLimit' => 100
     *    ],
     *    'Comments' => [ ... ]
     *  ];
     *  $results = $paginator->paginate($table, $settings);
     * ```
     *
     * This would allow you to have different pagination settings for `Articles` and `Comments` tables.
     *
     * ### Controlling sort fields
     *
     * By default CakePHP will automatically allow sorting on any column on the table object being
     * paginated. Often times you will want to allow sorting on either associated columns or calculated
     * fields. In these cases you will need to define a whitelist of all the columns you wish to allow
     * sorting on. You can define the whitelist in the `$settings` parameter:
     *
     * ```
     * $settings = [
     *   'Articles' => [
     *     'finder' => 'custom',
     *     'sortWhitelist' => ['title', 'author_id', 'comment_count'],
     *   ]
     * ];
     * ```
     *
     * Passing an empty array as whitelist disallows sorting altogether.
     *
     * ### Paginating with custom finders
     *
     * You can paginate with any find type defined on your table using the `finder` option.
     *
     * ```
     *  $settings = [
     *    'Articles' => [
     *      'finder' => 'popular'
     *    ]
     *  ];
     *  $results = $paginator->paginate($table, $settings);
     * ```
     *
     * Would paginate using the `find('popular')` method.
     *
     * You can also pass an already created instance of a query to this method:
     *
     * ```
     * $query = $this->Articles->find('popular')->matching('Tags', function ($q) {
     *   return $q->where(['name' => 'CakePHP'])
     * });
     * $results = $paginator->paginate($query);
     * ```
     *
     * ### Scoping Request parameters
     *
     * By using request parameter scopes you can paginate multiple queries in the same controller action:
     *
     * ```
     * $articles = $paginator->paginate($articlesQuery, ['scope' => 'articles']);
     * $tags = $paginator->paginate($tagsQuery, ['scope' => 'tags']);
     * ```
     *
     * Each of the above queries will use different query string parameter sets
     * for pagination data. An example URL paginating both results would be:
     *
     * ```
     * /dashboard?articles[page]=1&tags[page]=2
     * ```
     *
     * @param \Cake\Datasource\RepositoryInterface|\Cake\Datasource\QueryInterface $object The table or query to paginate.
     * @param array $settings The settings/configuration used for pagination.
     * @return \Cake\Datasource\ResultSetInterface Query results
     * @throws \Cake\Network\Exception\NotFoundException
     */
    public function paginate($object, array $settings = [])
    {
        $request = $this->_registry->getController()->request;

        try {
            $results = $this->_paginator->paginate(
                $object,
                $request->getQueryParams(),
                $settings
            );

            $this->_setPagingParams();
        } catch (PageOutOfBoundsException $e) {
            $this->_setPagingParams();

            throw new NotFoundException();
        }

        return $results;
    }

    /**
     * Merges the various options that Pagination uses.
     * Pulls settings together from the following places:
     *
     * - General pagination settings
     * - Model specific settings.
     * - Request parameters
     *
     * The result of this method is the aggregate of all the option sets combined together. You can change
     * config value `whitelist` to modify which options/values can be set using request parameters.
     *
     * @param string $alias Model alias being paginated, if the general settings has a key with this value
     *   that key's settings will be used for pagination instead of the general ones.
     * @param array $settings The settings to merge with the request data.
     * @return array Array of merged options.
     */
    public function mergeOptions($alias, $settings)
    {
        $request = $this->_registry->getController()->request;

        return $this->_paginator->mergeOptions(
            $request->getQueryParams(),
            $this->_paginator->getDefaults($alias, $settings)
        );
    }

    /**
     * Set paginator instance.
     *
     * @param \Cake\Datasource\Paginator $paginator Paginator instance.
     * @return self
     */
    public function setPaginator(Paginator $paginator)
    {
        $this->_paginator = $paginator;

        return $this;
    }

    /**
     * Get paginator instance.
     *
     * @return \Cake\Datasource\Paginator
     */
    public function getPaginator()
    {
        return $this->_paginator;
    }

    /**
     * Set paging params to request instance.
     *
     * @return void
     */
    protected function _setPagingParams()
    {
        $request = $this->_registry->getController()->request;

        $request->addParams([
            'paging' => $this->_paginator->getPagingParams()
                + (array)$request->getParam('paging')
        ]);
    }

    /**
     * Proxy getting/setting config options to Paginator.
     *
     * @deprecated 3.5.0 use setConfig()/getConfig() instead.
     * @param string|array|null $key The key to get/set, or a complete array of configs.
     * @param mixed|null $value The value to set.
     * @param bool $merge Whether to recursively merge or overwrite existing config, defaults to true.
     * @return mixed Config value being read, or the object itself on write operations.
     */
    public function config($key = null, $value = null, $merge = true)
    {
        $return = $this->_paginator->config($key, $value, $merge);
        if ($return instanceof Paginator) {
            $return = $this;
        }

        return $return;
    }

    /**
     * Proxy setting config options to Paginator.
     *
     * @param string|array $key The key to set, or a complete array of configs.
     * @param mixed|null $value The value to set.
     * @param bool $merge Whether to recursively merge or overwrite existing config, defaults to true.
     * @return $this
     */
    public function setConfig($key, $value = null, $merge = true)
    {
        $this->_paginator->setConfig($key, $value, $merge);

        return $this;
    }

    /**
     * Proxy getting config options to Paginator.
     *
     * @param string|null $key The key to get or null for the whole config.
     * @param mixed $default The return value when the key does not exist.
     * @return mixed Config value being read.
     */
    public function getConfig($key = null, $default = null)
    {
        return $this->_paginator->getConfig($key, $default);
    }

    /**
     * Proxy setting config options to Paginator.
     *
     * @param string|array $key The key to set, or a complete array of configs.
     * @param mixed|null $value The value to set.
     * @return $this
     */
    public function configShallow($key, $value = null)
    {
        $this->_paginator->configShallow($key, $value = null);

        return $this;
    }

    /**
     * Proxy method calls to Paginator.
     *
     * @param string $method Method name.
     * @param array $args Method arguments.
     * @return mixed
     */
    public function __call($method, $args)
    {
        return call_user_func_array([$this->_paginator, $method], $args);
    }
}