SmartEnums 2.1.3

SmartEnums

Info

SmartEnums is a simple library, written in C#.NET, which enables you to enhancing the capabilities of standard enum.

Installation

Either checkout this Github repository or install SmartEnums via NuGet Package Manager.

If you want to use NuGet just search for SmartEnums or run the following command in the NuGet Package Manager console:

PM> Install-Package SmartEnums

Usage

SmartEnums works on the basis of attributes, which means that now it becomes possible to store custom data for enumeration fields without resorting to writing classes.

• Adding fields
• Getting value
• Attribute versions
• Getting versioned value
• Enumeration
• Metadata

Adding fields

First, let's describe the enumeration we want to work with:

public enum UserSubscription
{
  OneMonth,
  SixMonth, 
  Year,
}

Now using attribute

EnumValueAttribute(string key, object value)

adding custom information in enumeration:

public enum UserSubscription
{
    [EnumValue("Price", 169.0)]
    [EnumValue("Description", "One month subscribe")]
    [EnumValue("Subscribe period", 31)]
    OneMonth,
    
    [EnumValue("Price", 600.50)]
    [EnumValue("Description", "Six month subscribe")]
    [EnumValue("Subscribe period", 31 * 6)]
    SixMonth, 
    
    [EnumValue("Price", 1000.0)]
    [EnumValue("Description", "One year subscribe")]
    [EnumValue("Subscribe period", 31 * 12)]
    Year,
}
//I know that the date count is incorrect, I just gave an example that you can store any data

Now you add custom fields in enumeration.

An attribute can store expressions. It's means that you can hold simple value types, typeof() expressions and other enum.

public enum Gender
{
    [EnumValue("Description", "he/him")]
    Male,
    
    [EnumValue("Description", "she/her")]
    Female,
}

public enum TemplateUser
{
    [EnumValue("Age", 20)]
    [EnumValue("Gender", Gender.Male)]
    Jhon,

    [EnumValue("Age", 25)]
    [EnumValue("Gender", Gender.Male)]
    Claus,

    [EnumValue("Age", 15)]
    [EnumValue("Gender", Gender.Female)]
    Elza
}

Getting value

In order to get the value of a custom field, you need to use the extension method

public static T GetValueOf<T>(this Enum element, string key)

In order not to duplicate the code, let's take the enumeration declared above:

var age = TemplateUser.Claus.GetValueOf<int>("Age"); //return 25
var genderDescription = TemplateUser.Claus.GetValueOf<Gender>("Gender").GetValueOf<string>("Description"); //return "he/him"

And now you got values of custom attribute fields.

Attribute versions

You can add your versions for attributes using same attribute with string version parameter

public enum UserSubscription
{
    [EnumValue("Price", 169.0, "1.0.0")]
    [EnumValue("Price", 300.0, "2.0.0")]
    [EnumValue("Price", 169.0, "2.0.1")]
    [EnumValue("Price", 300.0, "3.0.0")]
    OneMonth,
}

Versions implemented just as string type and you can make your own versions. But must remember that versions use standard strings comparison.

Getting versioned value

In order to get the versioned value of a custom field, you need to use the same extension method like without version but add version parameter

public static T GetValueOf<T>(this Enum element, string key, string version)

and get needed versioned value:

var price = UserSubscription.OneMonth.GetValueOf<double>("Price", "1.0.0"); //return 169.0

If you use method GetValueOf<T> without version for field that has some versions it return value of newest version.

Also you can get newest versions using keyword implemented in config class.

There are two keywords for get newest versions:

"latest",
"newest"

If you need to get a specific version or newer, you can use the ^ sign at the beginning of the parameter.

With this knowledge, you can get the value for the desired version.

var priceLatest = UserSubscription.OneMonth.GetValueOf<double>("Price", "latest"); //return 300.0
var priceNewest = UserSubscription.OneMonth.GetValueOf<double>("Price", "newest"); //return 300.0
var price = UserSubscription.OneMonth.GetValueOf<double>("Price", "^2.0.0"); //return 300.0

Some more good features

Enumeration

By default, C# does not have an enumeration for enums. I suggest this big omission and added a method that implements this functionality.

public static IEnumerable<T> GetEnumerator<T>()

//example
public enum Gender
{
  Male,
  Female
}

var genders = SmartEnum.GetEnumerator<Gender>(); //return IEnumerable<Gender> [Male, Female]

Metadata

Sometimes need get full information about used EnumValueAttribute in enum. For this situations you can get metadata of enum serialized to json or xml:

For get metadata in json format use next extension method:

public static string GetJsonMetadata(this Enum obj) 

For get metadata in xml format use next extansion method:

public static string GetXmlMetadata(this Enum obj)

That's all Folks!