Dotnet Enum has an [Flags]
attribute that gives us the ability to have a binary enum system and use bitwise operators.
However, enum specifically restricts to built-in numeric types which is a big problem because it is limited to 2^32 for int
values which means we only can have a maximum of 32 items in our enum or 2^64 for long
which limits us to a maximum of 64 items.
this library aims to remove these restrictions and still give us the same functionality.
To define an enum class, you can create a class/record and inherit it from InfiniteEnum<ClassName>
,
this base class, will help you to access the list of defined enum items.
then by adding static fields of type Flag<ClassName>
you can create your enums.
setting the values is imperative to provide values as powers of two.
e.g
public class Features : InfiniteEnum<Features>
{
public static readonly Flag<Features> None = new(-1); // 0 - 0
public static readonly Flag<Features> F1 = new(0); // 1 - 1
public static readonly Flag<Features> F2 = new(1); // 2 - 10
public static readonly Flag<Features> F3 = new(2); // 4 - 100
public static readonly Flag<Features> F4 = new(3); // 8 - 1000
public static readonly Flag<Features> F5 = new(4); // 16 - 10000
public static readonly Flag<Features> F6 = new(5); // 32 - 100000
public static readonly Flag<Features> F7 = new(6); // 64 - 1000000
public static readonly Flag<Features> F8 = new(7); // 128 - 10000000
// We can support up to 2,147,483,647 items
}
To use your custom enum, it is important to be familiar with the built-in dotnet enum flags capabilities
because the functionalities are almost identical.
for example we can use all bitwise operators (|
,&
,~
,^
) in our custom enum.
e.g
var features = Features.F1 | Features.F3; // F1 + F3
Alternatively, If you don't like bitwise Operators, you can use the Flag<> extension methods:
Name | Description |
---|---|
HasFlag | Check whatever enum has an specific flag or not, (bitwise &) |
SetFlag | Add/Set specific flag(s) to an enum, (bitwise or) |
UnsetFlag | Remove/Unset specific flag(s) from an enum (bitwise &~) |
ToggleFlag | It toggles flag(s) from an enum (bitwise ^) |
e.g
var features = Features.F1.SetFlag(Features.F3);
features.HasFlag(Features.F2); // false
Since we want to support more than 32 items in our enums, we can not store an integer
value, luckily we can use ToUniqueId()
function to get a unique base64 key, and to convert it back to an
Flag, we can use FromUniqueId()
static method.
var features = Features.F1 | Features.F3;
string id = features.ToUniqueId();
var new_features = Features.FromUniqueId(id);
Console.WriteLine(features == new_features); // true
One of the reasonable use cases that shows why we need this library is developing a flexible authorization in asp.net core applications that @Json Taylor presented very well in this video. However, his implementation using dotnet [Flags] had a massive limitation in big projects when we need more than 64 permissions. I provided an example of the same demo in the video using InfiniteEnumFlags that doesn't have these limitations.
To see flexible aspnetcore authorization example using InfiniteEnumFlags, first clone the repo using below command
git clone --recurse-submodules https://github.com/alirezanet/InfiniteEnumFlags.git
then you can open \InfiniteEnumFlags\Example\flexible-aspnetcore-authorization\FlexibleAuth\FlexibleAuth.sln
and then run the Server
project.
Admin Username: admin@localhost
Auditor Username: auditor@localhost
Default Password: Password123!
- Don't forget to give a β on GitHub
- Share your feedback and ideas to improve this library
- Share InfiniteEnumFlags on your favorite social media and your friends
- Write a blog post about InfiniteEnumFlags
Feel free to send me a pull request!