Mapster.Tool

Mapster.Tool

#skip this step if you already have dotnet-tools.json
dotnet new tool-manifest 

dotnet tool install Mapster.Tool

Commands

Mapster.Tool provides 3 commands

• model: generate models from entities
• extension: generate extension methods from entities
• mapper: generate mappers from interfaces

And Mapster.Tool provides following options

• -a: define input assembly
• -n: define namespace of generated classes
• -o: define output directory

csproj integration

Generate manually

add following code to your csproj file.

  <Target Name="Mapster">
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet build" />
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet tool restore" />
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet mapster model -a $(TargetDir)$(ProjectName).dll" />
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet mapster extension -a $(TargetDir)$(ProjectName).dll" />
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet mapster mapper -a $(TargetDir)$(ProjectName).dll" />
  </Target>

to generate run following command on csproj file directory:

dotnet msbuild -t:Mapster

Generate automatically on build

add following code to your csproj file.

  <Target Name="Mapster" AfterTargets="AfterBuild">
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet tool restore" />
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet mapster model -a $(TargetDir)$(ProjectName).dll" />
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet mapster extension -a $(TargetDir)$(ProjectName).dll" />
    <Exec WorkingDirectory="$(ProjectDir)" Command="dotnet mapster mapper -a $(TargetDir)$(ProjectName).dll" />
  </Target>

Clean up

add following code to your csproj file.

  <ItemGroup>
    <Generated Include="**\*.g.cs" />
  </ItemGroup>
  <Target Name="CleanGenerated">
    <Delete Files="@(Generated)" />
  </Target>

to clean up run following command:

dotnet msbuild -t:CleanGenerated

Generate models

Annotate your class with [AdaptFrom], [AdaptTo], or [AdaptTwoWays].

Example:

[AdaptTo("[name]Dto")]
public class Student {
    ...
}

Then Mapster will generate:

public class StudentDto {
    ...
}

Ignore some properties on generation

By default, code generation will ignore properties that annotated [AdaptIgnore] attribute. But you can add more settings which include IgnoreAttributes, IgnoreNoAttributes, IgnoreNamespaces.

Example:

[AdaptTo("[name]Dto", IgnoreNoAttributes = new[] { typeof(DataMemberAttribute) })]
public class Student {

    [DataMember]
    public string Name { get; set; }     //this property will be generated
    
    public string LastName { get; set; } //this will not be generated
}

Change property types

By default, if property type annotated with the same adapt attribute, code generation will forward to that type. (For example, Student has ICollection<Enrollment>, after code generation StudentDto will has ICollection<EnrollmentDto>).

You can override this by [PropertyType(typeof(Target))] attribute. This annotation can be annotated to either on property or on class.

For example:

[AdaptTo("[name]Dto")]
public class Student {
    public ICollection<Enrollment> Enrollments { get; set; }
}

[AdaptTo("[name]Dto"), PropertyType(typeof(DataItem))]
public class Enrollment {
    [PropertyType(typeof(string))]
    public Grade? Grade { get; set; }
}

This will generate:

public class StudentDto {
    public ICollection<DataItem> Enrollments { get; set; }
}
public class EnrollmentDto {
    public string Grade { get; set; }
}

Generate readonly properties

For [AdaptTo] and [AdaptTwoWays], you can generate readonly properties with MapToConstructor setting.

For example:

[AdaptTo("[name]Dto", MapToConstructor = true)]
public class Student {
    public string Name { get; set; }
}

This will generate:

public class StudentDto {
    public string Name { get; }

    public StudentDto(string name) {
        this.Name = name;
    }
}

Generate nullable properties

For [AdaptFrom], you can generate nullable properties with IgnoreNullValues setting.

For example:

[AdaptFrom("[name]Merge", IgnoreNullValues = true)]
public class Student {
    public int Age { get; set; }
}

This will generate:

public class StudentMerge {
    public int? Age { get; set; }
}

Generate extension methods

Generate using [GenerateMapper] attribute

For any POCOs annotate with [AdaptFrom], [AdaptTo], or [AdaptTwoWays], you can add [GenerateMapper] in order to generate extension methods.

Example:

[AdaptTo("[name]Dto"), GenerateMapper]
public class Student {
    ...
}

Then Mapster will generate:

public class StudentDto {
    ...
}
public static class StudentMapper {
    public static StudentDto AdaptToDto(this Student poco) { ... }
    public static StudentDto AdaptTo(this Student poco, StudentDto dto) { ... }
    public static Expression<Func<Student, StudentDto>> ProjectToDto => ...
}

Generate using configuration

You can also generate extension methods and add extra settings from configuration.

public class MyRegister : IRegister
{
    public void Register(TypeAdapterConfig config)
    {
        config.NewConfig<TSource, TDestination>()
            .GenerateMapper(MapType.Map | MapType.MapToTarget);
    }
}

Generate mapper from interface

Annotate your interface with [Mapper] in order for tool to pickup for generation.

This is example interface.

[Mapper]
public interface IProductMapper
{
    ProductDTO Map(Product customer);
}

You can add multiple members as you want. All member names are flexible, but signature must be in following patterns:

[Mapper]
public interface ICustomerMapper
{
    //for queryable
    Expression<Func<Customer, CustomerDTO>> ProjectToDto { get; }
    
    //map from POCO to DTO
    CustomerDTO MapToDto(Customer customer);

    //map to existing object
    Customer MapToExisting(CustomerDTO dto, Customer customer);
}

If you have configuration, it must be in IRegister

public class MyRegister : IRegister
{
    public void Register(TypeAdapterConfig config)
    {
        config.NewConfig<TSource, TDestination>();
    }
}

Sample

• https://github.com/MapsterMapper/Mapster/tree/master/src/Sample.CodeGen