# Migration guide for describeEnum and EnumProperty

> Learn about the removal of describeEnum and how to migrate.




:::important
These breaking change docs are accurate, as of the release
under which they are published. Over time, the
workarounds described here might become inaccurate.
We don't, in general, keep these breaking change docs up
to date as of each release.

这些破坏性改动文档的准确性仅限于其发布时对应的版本。
随着时间的推移，文档中描述的方案可能会逐渐失效。
通常情况下，我们不会在每次发布新版本时都对这些文档进行同步更新。

The [breaking change index file](/release/breaking-changes)
lists the docs created for each release.

[破坏性改动列表](/release/breaking-changes) 
列出了每个版本的文档。

:::


## Summary

The global method `describeEnum` has been deprecated. Previous uses
of `describeEnum(Enum.something)` should use
`Enum.something.name` instead.

The class `EnumProperty` was modified to
extend `<T extends Enum?>` instead of `<T>`.
Existing uses of `EnumProperty<NotAnEnum>` should
use `DiagnosticsProperty<NotAnEnum>` instead.

## Context

Dart 2.17 introduced [enhanced enums][], which added `Enum` as a type.
As a result, all enums got a `name` getter, which made `describeEnum`
redundant. Before that, enum classes were often analyzed using an
`EnumProperty`.

The `describeEnum` method was used to convert an enum value to a string,
since `Enum.something.toString()` would produce `Enum.something` instead
of `something`, which a lot of users wanted. Now, the `name` getter does this.

The `describeEnum` function is being deprecated,
so the `EnumProperty` class is updated to only accept `Enum` objects.

[enhanced enums]: https://dart.cn/language/enums#declaring-enhanced-enums

## Description of change

Remove `describeEnum`.

- Replace `describeEnum(Enum.something)` with `Enum.something.name`.

The `EnumProperty` now expects null or an `Enum`;
you can no longer pass it a non-`Enum` class.

## Migration guide

If you previously used `describeEnum(Enum.field)` to access the
string value from an enum, you can now call `Enum.field.name`.

If you previously used `EnumProperty<NotAnEnum>`, you can
now use the generic `DiagnosticsProperty<NotAnEnum>`.

Code before migration:

```dart
enum MyEnum { paper, rock }

print(describeEnum(MyEnum.paper)); // output: paper

// TextInputType is not an Enum
properties.add(EnumProperty<TextInputType>( ... ));
```

Code after migration:

```dart
enum MyEnum { paper, rock }

print(MyEnum.paper.name); // output: paper

// TextInputType is not an Enum
properties.add(DiagnosticsProperty<TextInputType>( ... ));
```

## Timeline

Landed in version: 3.14.0-2.0.pre<br>
In stable release: 3.16

## References

API documentation:

* [`describeEnum`][]
* [`EnumProperty`][]

Relevant issues:

* [Cleanup SemanticsFlag and SemanticsAction issue][]

Relevant PRs:

* [Deprecate `describeEnum` PR][]

[`describeEnum`]: https://api.flutter-io.cn/flutter/foundation/describeEnum.html
[`EnumProperty`]: https://api.flutter-io.cn/flutter/foundation/EnumProperty-class.html

[Cleanup SemanticsFlag and SemanticsAction issue]: https://github.com/flutter/flutter/issues/123346
[Deprecate `describeEnum` PR]: https://github.com/flutter/flutter/pull/125016