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\entities;

use coding_exception;

use core_reportbuilder\local\helpers\{database, join_trait};

use core_reportbuilder\local\report\column;

use core_reportbuilder\local\report\filter;

use lang_string;

/**

 * Base class for all report entities

 *

 * @package     core_reportbuilder

 * @copyright   2019 Marina Glancy <marina@moodle.com>

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

 */

abstract class base {

    use join_trait;

    /** @var string $entityname Internal reference to name of entity */

    private $entityname = null;

    /** @var lang_string $entitytitle Used as a title for the entity in reports */

    private $entitytitle = null;

    /** @var array $tablealiases Database tables that this entity uses and their aliases */

    private $tablealiases = [];

    /** @var array $tablejoinaliases Database tables that have already been joined to the report and their aliases */

    private $tablejoinaliases = [];

    /** @var column[] $columns List of columns for the entity */

    private $columns = [];

    /** @var filter[] $filters List of filters for the entity */

    private $filters = [];

    /** @var filter[] $conditions List of conditions for the entity */

    private $conditions = [];

    /**

     * Database tables that the entity expects to be present in the main SQL or in JOINs added to it

     *

     * @return string[]

     */

    abstract protected function get_default_tables(): array;

    /**

     * @deprecated since Moodle 4.4 - aliases are now autogenerated, please implement {@see get_default_tables} instead

     */

    #[\core\attribute\deprecated('::get_default_tables', since: '4.4', mdl: 'MDL-79397', final: true)]

    protected function get_default_table_aliases(): array {

        \core\deprecation::emit_deprecation([self::class, __FUNCTION__]);

        return [];

    }

    /**

     * Database tables that the entity once used but now no longer does. To prevent errors in third-party code, rather than

     * simply removing the table from {@see get_default_tables} you can override this method, which will emit developer debug

     *

     * Returns a simple list of table names, ['t1', 't2'] if they have no replacement; or ['t3' => 't1'] if an equivalent

     * replacement table name exists, where 't3' replaces 't1'

     *

     * @return string[]

     */

    protected function get_deprecated_tables(): array {

        return [];

    }

    /**

     * The default title for this entity

     *

     * @return lang_string

     */

    abstract protected function get_default_entity_title(): lang_string;

    /**

     * Initialise the entity, called automatically when it is added to a report

     *

     * This is where entity defines all its columns and filters by calling:

     * - {@see add_column}

     * - {@see add_filter}

     * - etc

     *

     * @return self

     */

    abstract public function initialise(): self;

    /**

     * The default machine-readable name for this entity that will be used in the internal names of the columns/filters

     *

     * @return string

     */

    private function get_default_entity_name(): string {

        $namespace = explode('\\', get_called_class());

        return end($namespace);

    }

    /**

     * Set entity name

     *

     * @param string $entityname

     * @return self

     */

    final public function set_entity_name(string $entityname): self {

        $this->entityname = $entityname;

        return $this;

    }

    /**

     * Return entity name

     *

     * @return string

     */

    final public function get_entity_name(): string {

        return $this->entityname ?? $this->get_default_entity_name();

    }

    /**

     * Set entity title

     *

     * @param lang_string $title

     * @return self

     */

    final public function set_entity_title(lang_string $title): self {

        $this->entitytitle = $title;

        return $this;

    }

    /**

     * Get entity title

     *

     * @return lang_string

     */

    final public function get_entity_title(): lang_string {

        return $this->entitytitle ?? $this->get_default_entity_title();

    }

    /**

     * Validate the given table is expected by the entity

     *

     * Emits developer debugging for deprecated tables, will return replacement for deprecated table if specified

     * by the entity

     *

     * @param string $tablename

     * @return string

     * @throws coding_exception For invalid table name

     */

    private function validate_table_name(string $tablename): string {

        $deprecatedtables = $this->get_deprecated_tables();

        if (!in_array($tablename, array_merge($this->get_default_tables(), $deprecatedtables))) {

            throw new coding_exception('Invalid table name', $tablename);

        }

        // Emit debugging if table is marked as deprecated by the entity.

        if (($tablenamereplacement = array_search($tablename, $deprecatedtables)) !== false) {

            debugging("The table '{$tablename}' is deprecated, please do not use it any more.", DEBUG_DEVELOPER);

            // An associative array contains the replacement table name as the key, so return that.

            if (!array_is_list($deprecatedtables)) {

                return $tablenamereplacement;

            }

        }

        return $tablename;

    }

    /**

     * Override the default alias for given database table used in entity queries, for instance when the same table is used

     * by multiple entities and you want them each to refer to it by the same alias

     *

     * @param string $tablename One of the tables set by {@see get_default_tables}

     * @param string $alias

     * @return self

     */

    final public function set_table_alias(string $tablename, string $alias): self {

        $tablename = $this->validate_table_name($tablename);

        $this->tablealiases[$tablename] = $alias;

        return $this;

    }

    /**

     * Override multiple default database table aliases used in entity queries as per {@see set_table_alias}

     *

     * @param array $aliases Array of tablename => alias values

     * @return self

     */

    final public function set_table_aliases(array $aliases): self {

        foreach ($aliases as $tablename => $alias) {

            $this->set_table_alias($tablename, $alias);

        }

        return $this;

    }

    /**

     * Returns an alias used in the queries for a given table

     *

     * @param string $tablename One of the tables set by {@see get_default_tables}

     * @return string

     */

    final public function get_table_alias(string $tablename): string {

        $tablename = $this->validate_table_name($tablename);

        // We don't have the alias yet, generate a new one.

        if (!array_key_exists($tablename, $this->tablealiases)) {

            $this->set_table_alias($tablename, database::generate_alias());

        }

        return $this->tablealiases[$tablename];

    }

    /**

     * Returns aliases used in the queries for all tables

     *

     * @return string[]

     */

    final public function get_table_aliases(): array {

        $tablenames = $this->get_default_tables();

        return array_combine($tablenames, array_map([$this, 'get_table_alias'], $tablenames));

    }

    /**

     * Set the alias for given database table that has already been added to the report. Enables entities to avoid additional

     * joins on the same table by allowing re-use of existing table aliases in their own queries, {@see has_table_join_alias}

     *

     * @param string $tablename

     * @param string $alias

     * @return self

     */

    final public function set_table_join_alias(string $tablename, string $alias): self {

        $this->tablejoinaliases[$tablename] = $alias;

        // Internally set the same table alias for the entity.

        return $this->set_table_alias($tablename, $alias);

    }

    /**

     * Determine whether defined table join alias was specified. Call {@see get_table_alias} to retrieve said value

     *

     * @param string $tablename

     * @return bool

     */

    final public function has_table_join_alias(string $tablename): bool {

        return array_key_exists($tablename, $this->tablejoinaliases);

    }

    /**

     * Helper method for returning joins necessary for retrieving tags related to the current entity

     *

     * Both 'tag' and 'tag_instance' aliases must be returned by the entity {@see get_default_tables} method

     *

     * @param string $component

     * @param string $itemtype

     * @param string $itemidfield

     * @return string[]

     */

    final protected function get_tag_joins_for_entity(string $component, string $itemtype, string $itemidfield): array {

        $taginstancealias = $this->get_table_alias('tag_instance');

        $tagalias = $this->get_table_alias('tag');

        return [

            "LEFT JOIN {tag_instance} {$taginstancealias}

                    ON {$taginstancealias}.component = '{$component}'

                   AND {$taginstancealias}.itemtype = '{$itemtype}'

                   AND {$taginstancealias}.itemid = {$itemidfield}",

            "LEFT JOIN {tag} {$tagalias}

                    ON {$tagalias}.id = {$taginstancealias}.tagid",

        ];

    }

    /**

     * Add a column to the entity

     *

     * @param column $column

     * @return self

     */

    final protected function add_column(column $column): self {

        $this->columns[$column->get_name()] = $column;

        return $this;

    }

    /**

     * Returns entity columns

     *

     * @return column[]

     */

    final public function get_columns(): array {

        return $this->columns;

    }

    /**

     * Returns an entity column

     *

     * @param string $name

     * @return column

     * @throws coding_exception For invalid column name

     */

    final public function get_column(string $name): column {

        if (!array_key_exists($name, $this->columns)) {

            throw new coding_exception('Invalid column name', $name);

        }

        return $this->columns[$name];

    }

    /**

     * Add a filter to the entity

     *

     * @param filter $filter

     * @return self

     */

    final protected function add_filter(filter $filter): self {

        $this->filters[$filter->get_name()] = $filter;

        return $this;

    }

    /**

     * Returns entity filters

     *

     * @return filter[]

     */

    final public function get_filters(): array {

        return $this->filters;

    }

    /**

     * Returns an entity filter

     *

     * @param string $name

     * @return filter

     * @throws coding_exception For invalid filter name

     */

    final public function get_filter(string $name): filter {

        if (!array_key_exists($name, $this->filters)) {

            throw new coding_exception('Invalid filter name', $name);

        }

        return $this->filters[$name];

    }

    /**

     * Add a condition to the entity

     *

     * @param filter $condition

     * @return $this

     */

    final protected function add_condition(filter $condition): self {

        $this->conditions[$condition->get_name()] = $condition;

        return $this;

    }

    /**

     * Returns entity conditions

     *

     * @return filter[]

     */

    final public function get_conditions(): array {

        return $this->conditions;

    }

    /**

     * Returns an entity condition

     *

     * @param string $name

     * @return filter

     * @throws coding_exception For invalid condition name

     */

    final public function get_condition(string $name): filter {

        if (!array_key_exists($name, $this->conditions)) {

            throw new coding_exception('Invalid condition name', $name);

        }

        return $this->conditions[$name];

    }

}