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/>.

namespace core_question\local\bank;

use core\output\datafilter;

/**

 * An abstract class for filtering/searching questions.

 *

 * @package    core_question

 * @copyright  2013 Ray Morris

 * @author     Safat Shahin <safatshahin@catalyst-au.net>

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

 */

abstract class condition {

    /** @var int The default filter type */

    const JOINTYPE_DEFAULT = datafilter::JOINTYPE_ANY;

    /** @var ?array Filter properties for this condition. */

    public ?array $filter;

    /** @var string SQL fragment to add to the where clause. */

    protected string $where = '';

    /** @var array query param used in where. */

    protected array $params = [];

    /**

     * Return title of the condition

     *

     * @return string title of the condition

     */

    abstract public function get_title();

    /**

     * Return filter class associated with this condition

     *

     * @return string filter class

     */

    abstract public function get_filter_class();

    /**

     * Extract the required filter from the provided question bank view.

     *

     * This will look for the filter matching {@see get_condition_key()}

     *

     * @param view|null $qbank

     */

    public function __construct(view $qbank = null) {

        if (is_null($qbank)) {

            return;

        }

        $this->filter = static::get_filter_from_list($qbank->get_pagevars('filter'));

        // Build where and params.

        [$this->where, $this->params] = $this->filter ? static::build_query_from_filter($this->filter) : ['', []];

    }

    /**

     * Whether customisation is allowed.

     *

     * @return bool

     */

    public function allow_custom() {

        return true;

    }

    /**

     * Whether multiple values are allowed .

     *

     * @return bool

     */

    public function allow_multiple() {

        return true;

    }

    /**

     * Initial values of the condition

     *

     * @return array

     */

    public function get_initial_values() {

        return [];

    }

    /**

     * Extra data specific to this condition.

     *

     * @return \stdClass

     */

    public function get_filteroptions(): \stdClass {

        return (object)[];

    }

    /**

     * Whether empty value is allowed

     *

     * @return bool

     */

    public function allow_empty() {

        return true;

    }

    /**

     * Whether this filter is required - if so it cannot be removed from the list of filters.

     *

     * @return bool

     */

    public function is_required(): bool {

        return false;

    }

    /**

     * Return this condition class

     *

     * @return string

     */

    public function get_condition_class() {

        return get_class($this);

    }

    /**

     * Each condition will need a unique key to be identified and sequenced by the api.

     * Use a unique string for the condition identifier, use string directly, dont need to use language pack.

     * Using language pack might break the filter object for multilingual support.

     *

     * @return string

     */

    public static function get_condition_key() {

        return '';

    }

    /**

     * Return an SQL fragment to be ANDed into the WHERE clause to filter which questions are shown.

     *

     * @return string SQL fragment. Must use named parameters.

     */

    public function where() {

        return $this->where;

    }

    /**

     * Return parameters to be bound to the above WHERE clause fragment.

     * @return array parameter name => value.

     */

    public function params() {

        return $this->params;

    }

    /**

     * Display GUI for selecting criteria for this condition. Displayed when Show More is open.

     *

     * Compare display_options(), which displays always, whether Show More is open or not.

     * @return bool|string HTML form fragment

     * @deprecated since Moodle 4.0 MDL-72321 - please do not use this function any more.

     * @todo Final deprecation on Moodle 4.1 MDL-72572

     */

    public function display_options_adv() {

        debugging('Function display_options_adv() is deprecated, please use filtering objects', DEBUG_DEVELOPER);

        return false;

    }

    /**

     * Display GUI for selecting criteria for this condition. Displayed always, whether Show More is open or not.

     *

     * Compare display_options_adv(), which displays when Show More is open.

     * @return bool|string HTML form fragment

     * @deprecated since Moodle 4.0 MDL-72321 - please do not use this function any more.

     * @todo Final deprecation on Moodle 4.1 MDL-72572

     */

    public function display_options() {

        debugging('Function display_options() is deprecated, please use filtering objects', DEBUG_DEVELOPER);

        return false;

    }

    /**

     * Get the list of available joins for the filter.

     *

     * @return array

     */

    public function get_join_list(): array {

        return [

            datafilter::JOINTYPE_NONE,

            datafilter::JOINTYPE_ANY,

            datafilter::JOINTYPE_ALL,

        ];

    }

    /**

     * Given an array of filters, pick the entry that matches the condition key and return it.

     *

     * @param array $filters Array of filters, keyed by condition.

     * @return ?array The filter that matches this condition

     */

    public static function get_filter_from_list(array $filters): ?array {

        return $filters[static::get_condition_key()] ?? null;

    }

    /**

     * Build query from filter value

     *

     * @param array $filter filter properties

     * @return array where sql and params

     */

    public static function build_query_from_filter(array $filter): array {

        return ['', []];

    }

}