[4.x]: Fields with enum as value type fail while saving

[gglnx]

What happened?

Description

I've build an field type which uses an enum as value type. While saving craft\services\Elements::duplicateElement() at line 1461 tries to clone the enum, but cloning of enums is not supported by PHP. A simple check with instanceof \UnitEnum (https://www.php.net/manual/en/class.unitenum.php) should fix that.

Steps to reproduce

1. Build a field type that uses enum as value type, for example: https://gist.github.com/gglnx/33b74794af4462f51a55532c71bb3071
2. Try to save an element with this field type

Craft CMS version

4.3.1

PHP version

8.1.11

Operating system and version

No response

Database type and version

No response

Image driver and version

No response

Installed plugins and versions

[brianjhanson]

Thanks for reporting and for the sample code! It was very helpful. I've opened a PR for this. We can't fully support enums until we require 8.1 but it should help out in the mean time.

[brandonkelly]

Craft 4.3.2 is out with that fix.

[gglnx]

@brandonkelly looks like your change in a4303f1 this broke my enum fields :(

Error: Trying to clone an uncloneable object of class Enum\EntryOrderEnum in vendor/craftcms/cms/src/services/Elements.php:1491
Stack trace:
#0 vendor/craftcms/cms/src/services/Revisions.php(162): craft\services\Elements->duplicateElement(Object(craft\elements\MatrixBlock), Array)
#1 vendor/craftcms/cms/src/services/Matrix.php(1035): craft\services\Revisions->createRevision(Object(craft\elements\MatrixBlock), 1, NULL, Array)
#2 vendor/craftcms/cms/src/fields/Matrix.php(1059): craft\services\Matrix->createRevisionBlocks(Object(craft\fields\Matrix), Object(craft\elements\Entry), Object(craft\elements\Entry))
#3 vendor/craftcms/cms/src/base/Element.php(4947): craft\fields\Matrix->afterElementPropagate(Object(craft\elements\Entry), true)
#4 vendor/craftcms/cms/src/elements/Entry.php(1976): craft\base\Element->afterPropagate(true)
#5 vendor/craftcms/cms/src/services/Elements.php(1641): craft\elements\Entry->afterPropagate(true)
#6 vendor/craftcms/cms/src/services/Revisions.php(162): craft\services\Elements->duplicateElement(Object(craft\elements\Entry), Array)
#7 vendor/craftcms/cms/src/elements/Entry.php(1980): craft\services\Revisions->createRevision(Object(craft\elements\Entry), 1, '')
#8 vendor/craftcms/cms/src/services/Elements.php(3164): craft\elements\Entry->afterPropagate(false)
#9 vendor/craftcms/cms/src/services/Elements.php(1063): craft\services\Elements->_saveElementInternal(Object(craft\elements\Entry), true, false, true, Array, false)
#10 vendor/craftcms/cms/src/controllers/ElementsController.php(957): craft\services\Elements->saveElement(Object(craft\elements\Entry))
#11 [internal function]: craft\controllers\ElementsController->actionSave()
#12 vendor/yiisoft/yii2/base/InlineAction.php(57): call_user_func_array(Array, Array)
#13 vendor/yiisoft/yii2/base/Controller.php(178): yii\base\InlineAction->runWithParams(Array)
#14 vendor/yiisoft/yii2/base/Module.php(552): yii\base\Controller->runAction('save', Array)
#15 vendor/craftcms/cms/src/web/Application.php(302): yii\base\Module->runAction('elements/save', Array)
#16 vendor/craftcms/cms/src/web/Application.php(627): craft\web\Application->runAction('elements/save', Array)
#17 vendor/craftcms/cms/src/web/Application.php(281): craft\web\Application->_processActionRequest(Object(craft\web\Request))
#18 vendor/yiisoft/yii2/base/Application.php(384): craft\web\Application->handleRequest(Object(craft\web\Request))
#19 web/index.php(14): yii\base\Application->run()
#20 {main}

[gglnx]

8.1+ reports for class_exists(UnitEnum::class) false too: https://3v4l.org/oPA8A

[brandonkelly]

@gglnx Doh, UnitEnum is an interface, not a class. Just released 4.4.3 with a fix.