MintPlayer.Mapper 10.21.1

Mapper-generator

This library contains source-generators that automatically generates mapper extension-methods for you.

Getting started

You need to install both MintPlayer.Mapper and MintPlayer.Mapper.Attributes packages in your project.

Basic mapping

This demo shows how you can:

• Rename properties
• Change data-types
• Use the generated extension methods

You can mark a class with [GenerateMapper(typeof(TargetType))] to generate a mapper to another type.

[GenerateMapper(typeof(PersonDto))]
public class Person
{
    [MapperAlias(nameof(PersonDto.Naam))]
    public string Name { get; set; }

    [MapperAlias(nameof(PersonDto.HoofdAdres))]
    public Address MainAddress { get; set; }

    [MapperAlias(nameof(PersonDto.ContactGegevens))]
    public ContactInfo[] ContactInfos { get; set; }

    [MapperAlias(nameof(PersonDto.Gewicht))]
    public double Weight { get; set; }
    
    // Property with a state (plaintext, base64, ...)
    [MapperState(EKeyType.Plain)]
    public string Key { get; set; }
}

public enum EKeyType
{
    Plain,
    Base64
}

public class PersonDto
{
    public string Naam { get; set; }
    public AddressDto HoofdAdres { get; set; }
    public ContactInfoDto[] ContactGegevens { get; set; }
    public string Gewicht { get; set; }
    
    // Property with a state (plaintext, base64, ...)
    [MapperState(EKeyType.Base64)]
    public string Key { get; set; }
}

public static class Conversions
{
    [MapperConversion]
    public static double StringToDouble(string input)
    {
        if (double.TryParse(input, out double result))
            return result;
        return 0;
    }

    [MapperConversion]
    public static string DoubleToString(double input)
    {
        return input.ToString();
    }

    // Conversion inbetween states, same property types
    [MapperConversion<EKeyType>(EKeyType.Plain, EKeyType.Base64)]
    public static string StringToBase64(string input)
    {
        var bytes = System.Text.Encoding.UTF8.GetBytes(input);
        return Convert.ToBase64String(bytes);
    }

    [MapperConversion<EKeyType>(EKeyType.Base64, EKeyType.Plain)]
    public static string Base64ToString(string input)
    {
        var bytes = Convert.FromBase64String(input);
        return System.Text.Encoding.UTF8.GetString(bytes);
    }
}

Usage

var person = new Person {
    Name = "John Doe",
    Age = 30,
    Address = new Address {
        Street = "123 Main St",
        City = "Anytown"
    },
    ContactInfos = new List<ContactInfo> {
        new ContactInfo { Type = "Email", Value = "info@example.com" },
        new ContactInfo { Type = "Phone", Value = "123-456-7890" }
    },
    Notes = new List<string> { "Note 1", "Note 2" },
    Weight = 70.5,
    Password = "QWJjMTIzIQ==",
};
var dto = person.MapToPersonDto();
var entity = dto.MapToPerson();
Debugger.Break();

Example

A more complete example is available here.

Assembly-Level Usage

If you cannot apply [GenerateMapper] directly on a type (e.g. third-party classes), you can also apply it on the assembly:

[assembly: GenerateMapper(typeof(SourceType), typeof(TargetType))]

This will generate a mapper between the given types at the assembly level.

Property States

In some cases, two properties may share the same type (e.g. both are string) but represent different formats.
Normally, these properties would be assigned directly without passing through a conversion.

You can explicitly mark such properties with a [MapperState("statename")] attribute.
This ensures that the mapping will still go through the ConvertProperty<> method and apply the appropriate MapperConversion.

public enum EKeyType
{
    Plain,
    Base64
}

public class PlainKeyDto
{
    [MapperState(EKeyType.Plain)]
    public string Key { get; set; }
}

public class Base64KeyDto
{
    [MapperState(EKeyType.Base64)]
    public string Key { get; set; }
}

public static class Conversions
{
    [MapperConversion(EKeyType.Plain, EKeyType.Base64)]
    public static string ToBase64(string plain, EKeyType inType, EKeyType outType)
        => Convert.ToBase64String(Encoding.UTF8.GetBytes(plain));

    [MapperConversion(EKeyType.Base64, EKeyType.Plain)]
    public static string FromBase64(string base64, EKeyType inType, EKeyType outType)
        => Encoding.UTF8.GetString(Convert.FromBase64String(base64));
}

In this example:

• Both properties are string
• Without [MapperState], the mapper would assign Key directly
• With [MapperState], the mapper forces a conversion:
  • plain → base64 calls ToBase64
  • base64 → plain calls FromBase64

This makes it possible to handle format-specific conversions even when the property types are identical.

Complete example

using MintPlayer.Mapper.Attributes;
using System.Diagnostics;
using MapperDemo;


var person = new Person
{
    Name = "John Doe",
    MainAddress = new Address
    {
        Street = "123 Main St",
        City = "Anytown",
        Country = "USA",
        Number = "A1",
        PostalCode = "12345",
    },
    ContactInfos = [
        new ContactInfo { Type = "Email", Value = "info@example.com" },
        new ContactInfo { Type = "Phone", Value = "123-456-7890" }
    ],
    Notes = ["Note 1", "Note 2"],
    Weight = 70.5,
    Key = "QWJjMTIzIQ==",
};
var dto = person.MapToPersonDto();
var entity = dto.MapToPerson();
Debugger.Break();

namespace MapperDemo
{
    [GenerateMapper(typeof(PersonDto))]
    public class Person
    {
        [MapperAlias(nameof(PersonDto.Naam))]
        public string Name { get; set; }

        [MapperAlias(nameof(PersonDto.HoofdAdres))]
        public Address MainAddress { get; set; }

        [MapperAlias(nameof(PersonDto.Notities))]
        public string[] Notes { get; set; }

        [MapperAlias(nameof(PersonDto.ContactGegevens))]
        public ContactInfo[] ContactInfos { get; set; }

        [MapperAlias(nameof(PersonDto.Gewicht))]
        public double Weight { get; set; }

        // Property with a state (plaintext, base64, ...)
        [MapperState<EKeyType>(EKeyType.Plain)]
        public string Key { get; set; }
    }

    [GenerateMapper(typeof(AddressDto))]
    public class Address
    {
        [MapperAlias(nameof(AddressDto.Straat))]
        public string Street { get; set; }
        [MapperAlias(nameof(AddressDto.Nummer))]
        public string Number { get; set; }
        [MapperAlias(nameof(AddressDto.Gemeente))]
        public string City { get; set; }
        [MapperAlias(nameof(AddressDto.Postcode))]
        public string PostalCode { get; set; }
        [MapperAlias(nameof(AddressDto.Land))]
        public string Country { get; set; }
    }

    [GenerateMapper(typeof(ContactInfoDto))]
    public class ContactInfo
    {
        [MapperAlias(nameof(ContactInfoDto.Type))]
        public string Type { get; set; }
        [MapperAlias(nameof(ContactInfoDto.Waarde))]
        public string Value { get; set; }
    }

    public class PersonDto
    {
        public string Naam { get; set; }
        public AddressDto HoofdAdres { get; set; }
        public string[] Notities { get; set; }
        public ContactInfoDto[] ContactGegevens { get; set; }
        public string Gewicht { get; set; }

        // Property with a state (plaintext, base64, ...)
        [MapperState<EKeyType>(EKeyType.Base64)]
        public string Key { get; set; }
    }

    public class AddressDto
    {
        public string Straat { get; set; }
        public string Nummer { get; set; }
        public string Gemeente { get; set; }
        public string Postcode { get; set; }
        public string Land { get; set; }
    }

    public class ContactInfoDto
    {
        public string Type { get; set; }
        public string Waarde { get; set; }
    }

    public enum EKeyType
    {
        Plain,
        Base64
    }


    public static class Conversions
    {
        [MapperConversion]
        public static double StringToDouble(string input)
        {
            if (double.TryParse(input, out double result))
                return result;
            return 0;
        }

        [MapperConversion]
        public static string DoubleToString(double input)
        {
            return input.ToString();
        }

        // Conversion inbetween states, same property types
        [MapperConversion<EKeyType>(EKeyType.Plain, EKeyType.Base64)]
        public static string StringToBase64(string input)
        {
            var bytes = System.Text.Encoding.UTF8.GetBytes(input);
            return Convert.ToBase64String(bytes);
        }

        [MapperConversion<EKeyType>(EKeyType.Base64, EKeyType.Plain)]
        public static string Base64ToString(string input)
        {
            var bytes = Convert.FromBase64String(input);
            return System.Text.Encoding.UTF8.GetString(bytes);
        }
    }
}