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/>.

/**

 * Base implementation of a contextlist.

 *

 * @package    core_privacy

 * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>

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

 */

namespace core_privacy\local\request;

defined('MOODLE_INTERNAL') || die();

/**

 * Base implementation of a contextlist used to store a set of contexts.

 *

 * @copyright  2018 Andrew Nicols <andrew@nicols.co.uk>

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

 */

abstract class contextlist_base implements

        // Implement an Iterator to fetch the Context objects.

        \Iterator,

        // Implement the Countable interface to allow the number of returned results to be queried easily.

        \Countable {

    /**

     * @var array List of context IDs.

     *

     * Note: this must not be updated using set_contextids only as this

     * ensures uniqueness.

     */

    private $contextids = [];

    /**

     * @var string component the frankenstyle component name.

     */

    protected $component = '';

    /**

     * @var int Current position of the iterator.

     */

    protected $iteratorposition = 0;

    /**

     * Set the contextids.

     *

     * @param   array   $contextids The list of contexts.

     */

    protected function set_contextids(array $contextids) {

        $this->contextids = array_unique($contextids);

    }

    /**

     * Get the list of context IDs that relate to this request.

     *

     * @return  int[]

     */

    public function get_contextids(): array {

        return $this->contextids;

    }

    /**

     * Get the complete list of context objects that relate to this

     * request.

     *

     * @return  \context[]

     */

    public function get_contexts(): array {

        $contexts = [];

        foreach ($this->contextids as $contextid) {

            // It is possible that this context has been deleted and we now have subsequent calls being made with this

            // contextlist. Exceptions here will stop the further processing of this component and that is why we are

            // doing a try catch.

            try {

                $contexts[] = \context::instance_by_id($contextid);

            } catch (\Exception $e) {

                // Remove this context.

                unset($this->contextids[$this->iteratorposition]);

            }

        }

        return $contexts;

    }

    /**

     * Sets the component for this contextlist.

     *

     * @param string $component the frankenstyle component name.

     */

    protected function set_component($component) {

        $this->component = $component;

    }

    /**

     * Get the name of the component to which this contextlist belongs.

     *

     * @return string the component name associated with this contextlist.

     */

    public function get_component(): string {

        return $this->component;

    }

    /**

     * Return the current context.

     *

     * @return  \context

     */

    #[\ReturnTypeWillChange]

    public function current() {

        // It is possible that this context has been deleted and we now have subsequent calls being made with this

        // contextlist. Exceptions here will stop the further processing of this component and that is why we are

        // doing a try catch.

        try {

            $context = \context::instance_by_id($this->contextids[$this->iteratorposition]);

        } catch (\Exception $e) {

            // Remove this context.

            unset($this->contextids[$this->iteratorposition]);

            // Check to see if there are any more contexts left.

            if ($this->count()) {

                // Move the pointer to the next record and try again.

                $this->next();

                $context = $this->current();

            } else {

                // There are no more context ids left.

                return null;

            }

        }

        return $context;

    }

    /**

     * Return the key of the current element.

     *

     * @return  mixed

     */

    #[\ReturnTypeWillChange]

    public function key() {

        return $this->iteratorposition;

    }

    /**

     * Move to the next context in the list.

     */

    public function next(): void {

        ++$this->iteratorposition;

    }

    /**

     * Check if the current position is valid.

     *

     * @return  bool

     */

    public function valid(): bool {

        return isset($this->contextids[$this->iteratorposition]);

    }

    /**

     * Rewind to the first found context.

     *

     * The list of contexts is uniqued during the rewind.

     * The rewind is called at the start of most iterations.

     */

    public function rewind(): void {

        $this->iteratorposition = 0;

    }

    /**

     * Return the number of contexts.

     */

    public function count(): int {

        return count($this->contextids);

    }

}