Proyectos de Subversion Moodle

<?php

// This file is part of Moodle - http://moodle.org/

//

// Moodle is free software: you can redistribute it and/or modify

// it under the terms of the GNU General Public License as published by

// the Free Software Foundation, either version 3 of the License, or

// (at your option) any later version.

//

// Moodle is distributed in the hope that it will be useful,

// but WITHOUT ANY WARRANTY; without even the implied warranty of

// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

// GNU General Public License for more details.

//

// You should have received a copy of the GNU General Public License

// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**

 * Class paginator.

 *

 * @package    block_dash

 * @copyright  2019 bdecent gmbh <https://bdecent.de>

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace block_dash\local;

use renderer_base;

/**

 * Class paginator.

 *

 * @package block_dash

 */

class paginator {

    /**

     * Template name.

     */

    const TEMPLATE = 'block_dash/paginator';

    /**

     * Per page default.

     */

    const PER_PAGE_DEFAULT = 10;

    /**

     * @var int Pagination per page.

     */

    protected $perpage;

    /**

     * @var int Pagination current page.

     */

    protected $currentpage;

    /**

     * @var callable Provided function to get count of items.

     */

    protected $countfunction;

    /**

     * @var bool If true, a human readable summary will be displayed above paginator (Showing x of x out of x).

     */

    protected $showpagesummary;

    /**

     * paginator constructor.

     * @param callable $countfunction

     * @param int $currentpage

     * @param int $perpage

     * @param bool $showpagesummary If true, a human readable summary will be displayed above paginator (Showing x of x out of x).

     * @throws \coding_exception

     */

    public function __construct(callable $countfunction, $currentpage = 0, $perpage = self::PER_PAGE_DEFAULT,

                                $showpagesummary = true) {

        if (!is_int($perpage)) {

            throw new \coding_exception('Per page value must be an integer.');

        }

        $this->perpage = $perpage;

        $this->currentpage = $currentpage;

        $this->countfunction = $countfunction;

        $this->showpagesummary = $showpagesummary;

    }

    /**

     * Get mustache template.

     *

     * @return string

     */

    public function get_template() {

        return self::TEMPLATE;

    }

    /**

     * Get limit from for query.

     *

     * @return float|int

     */

    public function get_limit_from() {

        return $this->get_current_page() * $this->perpage;

    }

    /**

     * Get per page for query.

     *

     * @return int

     */

    public function get_per_page() {

        return $this->perpage;

    }

    /**

     * Set per page for query.

     *

     * @param int $perpage

     */

    public function set_per_page($perpage) {

        $this->perpage = $perpage;

    }

    /**

     * Get current page for query.

     *

     * @return int

     */

    public function get_current_page() {

        return $this->currentpage;

    }

    /**

     * Set current page for query.

     *

     * @param int $page

     */

    public function set_current_page($page) {

        $this->currentpage = $page;

    }

    /**

     * Get count of all records.

     *

     * @return int

     */

    public function get_record_count() {

        $function = $this->countfunction;

        return $function();

    }

    /**

     * Get number of pages based on per page and count.

     *

     * @return int

     */

    public function get_page_count() {

        $count = $this->get_record_count();

        if ($count > 0) {

            return ceil($count / $this->get_per_page());

        }

        // Default to 0 pages.

        return 0;

    }

    /**

     * Get variables for template.

     *

     * @param renderer_base $output

     * @return array

     * @throws \coding_exception

     */

    public function export_for_template(renderer_base $output) {

        $count = $this->get_page_count();

        $frontdivider = false;

        $backdivider = false;

        $items = [];

        for ($i = 0; $i < $count; $i++) {

            $items[$i] = [

                'index' => $i,

                'page' => $i,

                'label' => $i + 1,

                'active' => $this->get_current_page() == $i,

            ];

        }

        // There's some hard coded values here. Maybe at some point clean up this algorithm.

        // But for now it works just fine.

        if ($this->get_current_page() >= 5) {

            for ($i = 1; $i < $this->get_current_page() - 2; $i++) {

                unset($items[$i]);

            }

            $frontdivider = true;

        }

        if ($this->get_page_count() - 1 >= $this->get_current_page() + 3) {

            $pagecount = $this->get_page_count();

            for ($i = $this->get_current_page() + 3; $i < $pagecount - 2; $i++) {

                unset($items[$i]);

                $backdivider = true;

            }

        }

        if ($frontdivider) {

            $items[1] = [

                'label' => '...',

                'disabled' => true,

            ];

            ksort($items);

        }

        if ($backdivider) {

            end($items);

            $items[key($items) - 1] = [

                'label' => '...',

                'disabled' => true,

            ];

            ksort($items);

        }

        // Add previous and next buttons.

        array_unshift($items, [

            'label' => get_string('previous'),

            'page' => $this->get_current_page() - 1,

            'disabled' => $this->get_current_page() == 0,

        ]);

        // Next button.

        $items[] = [

            'label' => get_string('next'),

            'page' => $this->get_current_page() + 1,

            'disabled' => $this->get_current_page() == $count - 1 || empty($count),

        ];

        $recordcount = $this->get_record_count();

        $limitto = (int)$this->get_per_page() + (int)$this->get_limit_from();

        if ($limitto > $recordcount) {

            $limitto = $recordcount;

        }

        // If there's no records hide the summary.

        if ($recordcount == 0) {

            $this->showpagesummary = false;

        }

        $summary = get_string('pagination_summary', 'block_dash', [

            'total' => $this->get_record_count(),

            'per_page' => $this->get_per_page(),

            'limit_from' => $this->get_limit_from() + 1,

            'limit_to' => $limitto,

        ]);

        return [

            'pages' => $items,

            'show_page_summary' => $this->showpagesummary,

            'summary' => $summary,

        ];

    }

}