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/>.

declare(strict_types=1);

namespace core_reportbuilder\local\filters;

use MoodleQuickForm;

use core_reportbuilder\local\report\filter;

use core_reportbuilder\local\models\filter as filter_model;

/**

 * Base class for all report filters

 *

 * Filters provide a form for collecting user input, and then return appropriate SQL fragments based on these values

 *

 * @package     core_reportbuilder

 * @copyright   2021 Paul Holden <paulh@moodle.com>

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

 */

abstract class base {

    /** @var filter $filter */

    protected $filter;

    /** @var string $name */

    protected $name;

    /**

     * Do not allow the constructor to be called directly or overridden

     *

     * @param filter $filter

     */

    private function __construct(filter $filter) {

        $this->filter = $filter;

        $this->name = $filter->get_unique_identifier();

    }

    /**

     * Creates an instance of a filter type, based on supplied report filter instance

     *

     * The report filter instance is used by reports/entities to define what should be filtered against, e.g. a SQL fragment

     *

     * @param filter $filter The report filter instance

     * @return static

     */

    final public static function create(filter $filter): self {

        $filterclass = $filter->get_filter_class();

        return new $filterclass($filter);

    }

    /**

     * Returns the filter header

     *

     * @return string

     */

    final public function get_header(): string {

        return $this->filter->get_header();

    }

    /**

     * Returns the filter's entity name

     *

     * @return string

     */

    final public function get_entity_name(): string {

        return $this->filter->get_entity_name();

    }

    /**

     * Returns the filter persistent

     *

     * Note that filters for system reports don't store a persistent and will return null.

     *

     * @return filter_model|null

     */

    final public function get_filter_persistent(): ?filter_model {

        return $this->filter->get_persistent();

    }

    /**

     * Adds filter-specific form elements

     *

     * @param MoodleQuickForm $mform

     */

    abstract public function setup_form(MoodleQuickForm $mform): void;

    /**

     * Returns the filter clauses to be used with SQL where

     *

     * Ideally the field SQL should be included only once in the returned expression, however if that is unavoidable then

     * use the {@see filter::get_field_sql_and_params} helper to ensure uniqueness of any parameters included within

     *

     * @param array $values

     * @return array [$sql, [...$params]]

     */

    abstract public function get_sql_filter(array $values): array;

    /**

     * Given an array of current filter values for the report, determine whether the filter would apply to the report (i.e. user

     * has configured it from it's initial "Any value" state). A filter would typically be considered applied if it returns SQL

     * filter clauses, but child classes may override this method if they use different logic

     *

     * @param array $values

     * @return bool

     */

    public function applies_to_values(array $values): bool {

        [$filtersql] = $this->get_sql_filter($values);

        return $filtersql !== '';

    }

    /**

     * Return sample filter values, that when applied to a report would activate the filter - that is, cause the filter to return

     * SQL snippet. Should be overridden in child classes, to ensure compatibility with stress tests of reports

     *

     * @return array

     */

    public function get_sample_values(): array {

        return [];

    }

}