Id22

A wrapper against Guid.

• Id22
  • Purpose
  • Usage
  • Utils
  • Converters
    • System.Id22Converters
    • Microsoft.EntityFramework.Id22Converters
      • Setup
  • Tips
    • Swagger

Purpose

I made this library to solve the issue of serializing Guid to string for web apis.

It makes them url friendly with the usage of Base64 and short (22 characters).

While it's possible to use libraries for the purpose of converting to such, no library (that I know of) has made a type that can be stored as Guid, yet presented as string.

So this library provides, with the help of converters, Id22 can be used instead of Guid, to be stored as Guid, but viewed as a nice short string.

Usage

To use in you code, you just need this:

public class Book
{
    // No need to add or prepare anything, except for ef DbContext.
    public Id22 Id { get; set; } 
    
    public required string Name { get; set; }

    // Maybe this attribute is not necessary. 
    // Testing is required.
    [JsonConverter(typeof(Id22Converters.NullableJsonConverter))]
    public Id22? PublisherId { get; set; }
}

Utils

Id22 provides:

• New to create new value.
• ValueOrNew checks if value is valid for use. Returns new one if not.
• ValueOrDefault checks if value is valid for use. Returns default if not.
• IsEmpty to check if value is null, default or empty guid.

String Utils:

• ToShortId to convert Id22 to base64 22-character string.
• FromShortId to convert string to Id22 if possible.
• StringIsNotValidShortId to check whether it's possible to convert string back to Id22 or not.
• Parse to convert string to Id22 whether it's guid format or short id format.

Converters

Converters are provided by System.Id22Converters and Microsoft.EntityFramework.Id22Converters classes.

Warning

All converters are using ToString() when converting to string value so implementation is unified across them. This means if you use string converter for DbContext, it will store short ids. This may cause issues, so better not to use it, but use guid converter instead.

System.Id22Converters

This class provides implementations for:

• TypeConverter: applied by [TypeConverter] annotation. No need for extra setup.
• JsonConverter: also applied by [JsonConverter] annotation. Might need to apply nullable converter.

Microsoft.EntityFramework.Id22Converters

This class provides implementations of ValueConverter for EF Core.

It's available through nuget package Id22.EntityFrameworkCore.

Setup

Usage with DbContext:

public class DataContext : DbContext
{
    protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
    {
        base.ConfigureConventions(configurationBuilder);

        // ... configs

        configurationBuilder.MapId22ToGuid(); 

        // or to store as string

        // If string values can be generated as guid from the db,
        // then avoid using this.
        configurationBuilder.MapId22ToString();

        // ... configs
    }
}

Tips

If you have a global using file, you can add:

global using Id = Id22;

so you use Id instead of Id22.

Swagger

When using swagger, it can't pickup the json serializer.

So add this config line to show al Id22 properties as string:

builder.Services.AddSwaggerGen(
    (opt) =>
    {

        ...configs

        opt.MapType<Id>(
            () =>
                new OpenApiSchema
                {
                    Type = "string",
                    Example = new OpenApiString("A1C2E3G4I5K6M7O8Q9E0-_"),
                }
        );

        ...configs
    }
)