moodle/lib/classes/deprecation.php

258 lines
8.2 KiB
PHP

<?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;
use core\attribute\deprecated;
use core\attribute\deprecated_with_reference;
/**
* Deprecation utility.
*
* @package core
* @copyright 2024 Andrew Lyons <andrew@nicols.co.uk>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class deprecation {
/**
* Get the attribute from a reference.
*
* The reference can be:
* - a string, in which case it will be checked for a function, class, method, property, constant, or enum.
* - an array
* - an instantiated object, in which case the object will be checked for a class, method, property, or constant.
*
* @param array|string|object $reference A reference to a potentially deprecated thing.
* @return null|deprecated
*/
public static function from(array|string|object $reference): ?deprecated {
if (is_string($reference)) {
if (str_contains($reference, '::')) {
// The reference is a string but it looks to be in the format `object::item`.
return self::from(explode('::', $reference));
}
if (class_exists($reference) || interface_exists($reference) || trait_exists($reference)) {
// The reference looks to be a class name.
return self::from([$reference]);
}
if (function_exists($reference)) {
// The reference looks to be a global function.
return self::get_attribute(new \ReflectionFunction($reference), $reference);
}
return null;
}
if (is_object($reference)) {
// The reference is an object. Normalise and check again.
return self::from([$reference]);
}
if (is_array($reference) && count($reference)) {
if (is_object($reference[0])) {
$rc = new \ReflectionObject($reference[0]);
if ($rc->isEnum() && $reference[0]->name) {
// Enums can be passed via ::from([enum::NAME]).
// In this case they will have a 'name', which must exist.
return self::from_reflected_object($rc, $reference[0]->name);
}
return self::from_reflected_object($rc, $reference[1] ?? null);
}
if (is_string($reference[0])) {
if (class_exists($reference[0]) || interface_exists($reference[0]) || trait_exists($reference[0])) {
$rc = new \ReflectionClass($reference[0]);
return self::from_reflected_object($rc, $reference[1] ?? null);
}
}
// The reference is an array, but it's not an object or a class that currently exists.
return null;
}
// The reference is none of the above.
return null;
}
/**
* Get a deprecation attribute from a reflector.
*
* @param \Reflector $ref The reflector
* @param string $owner A descriptor of the owner of the thing that is deprecated
* @return null|deprecated_with_reference
*/
protected static function get_attribute(
\Reflector $ref,
string $owner,
): ?deprecated_with_reference {
if ($attributes = $ref->getAttributes(deprecated::class)) {
$attribute = $attributes[0]->newInstance();
return new deprecated_with_reference(
owner: $owner,
replacement: $attribute->replacement,
since: $attribute->since,
reason: $attribute->reason,
mdl: $attribute->mdl,
final: $attribute->final,
emit: $attribute->emit,
);
}
return null;
}
/**
* Check if a reference is deprecated.
*
* @param array|string|object $reference
* @return bool
*/
public static function is_deprecated(array|string|object $reference): bool {
return self::from($reference) !== null;
}
/**
* Emit a deprecation notice if the reference is deprecated.
*
* @param array|string|object $reference
*/
public static function emit_deprecation_if_present(array|string|object $reference): void {
if ($attribute = self::from($reference)) {
self::emit_deprecation_notice($attribute);
}
}
/**
* Fetch a referenced deprecation attribute from a reflected object.
*
* @param \ReflectionClass $rc The reflected object
* @param null|string $name The name of the thing to check for deprecation
* @return null|deprecated_with_reference
*/
protected static function from_reflected_object(
\ReflectionClass $rc,
?string $name,
): ?deprecated_with_reference {
// Check if the class itself is deprecated first.
$classattribute = self::get_attribute($rc, $rc->name);
if ($classattribute || $name === null) {
return $classattribute;
}
// Check for any deprecated interfaces.
foreach ($rc->getInterfaces() as $interface) {
if ($attribute = self::get_attribute($interface, $interface->name)) {
return $attribute;
}
}
// And any deprecated traits.
foreach ($rc->getTraits() as $trait) {
if ($attribute = self::get_attribute($trait, $trait->name)) {
return $attribute;
}
}
if ($rc->hasConstant($name)) {
// This class has a constant with the specified name.
// Note: This also applies to enums.
return self::get_attribute(
$rc->getReflectionConstant($name),
"{$rc->name}::{$name}",
);
}
if ($rc->hasMethod($name)) {
// This class has a method with the specified name.
return self::get_attribute(
$rc->getMethod($name),
"{$rc->name}::{$name}",
);
}
if ($rc->hasProperty($name)) {
// This class has a property with the specified name.
return self::get_attribute(
$rc->getProperty($name),
"{$rc->name}::{$name}",
);
}
return null;
}
/**
* Get a string describing the deprecation.
*
* @param deprecated $attribute
* @param string $owner
* @return string
*/
public static function get_deprecation_string(
deprecated $attribute,
): string {
$output = "Deprecation:";
if ($attribute instanceof deprecated_with_reference) {
$output .= " {$attribute->owner}";
}
$output .= " has been deprecated";
if ($attribute->since) {
$output .= " since {$attribute->since}";
}
$output .= ".";
if ($attribute->reason) {
$output .= " {$attribute->reason}.";
}
if ($attribute->replacement) {
$output .= " Use {$attribute->replacement} instead.";
}
if ($attribute->mdl) {
$output .= " See {$attribute->mdl} for more information.";
}
return $output;
}
/**
* Emit the relevant deprecation notice.
*
* @param deprecated $attribute
*/
protected static function emit_deprecation_notice(
deprecated $attribute,
): void {
if (!$attribute->emit) {
return;
}
$message = self::get_deprecation_string($attribute);
if ($attribute->final) {
throw new \coding_exception($message);
}
debugging($message, DEBUG_DEVELOPER);
}
}