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Settings - Two-ways mapping

docs/articles/settings/custom/Two-ways.md

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If you need to map object from POCO to DTO, and map back from DTO to POCO. You can define the setting once by using TwoWays.

csharp
TypeAdapterConfig<Poco, Dto>
    .NewConfig()
    .TwoWays()
    .Map(dto => dto.Code, poco => poco.Id); //<-- this setting will apply dto.Code = poco.Id & poco.Id = dto.Code for reverse mapping

NOTE: TwoWays command need to call before setting to take effect.

csharp
TypeAdapterConfig<Poco, Dto>
    .NewConfig()
    .Map(dto => dto.Foo, poco => poco.Bar)  //<-- this map only apply to Poco->Dto
    .TwoWays()
    .Map(dto => dto.Foz, poco => poco.Baz); //<-- this map will apply both side

Flattening

By default, Mapster will perform flattening.

csharp
class Staff {
    public string Name { get; set; }
    public Staff Supervisor { get; set; }
    ...
}

struct StaffDto {
    public string SupervisorName { get; set; }
}

Above example, without any setup, you can map from POCO to DTO and you will get SupervisorName from Supervisor.Name.

Using Unflattening

However, unflattening process needed to be defined. You can map to Supervisor.Name from SupervisorName by Unflattening setting.

csharp
TypeAdapterConfig<StaffDto, Staff>.NewConfig()
    .Unflattening(true);

Using TwoWays

Or you can use TwoWays to define both flattening and unflattening in one setting.

csharp
TypeAdapterConfig<Staff, StaffDto>
    .NewConfig()
    .TwoWays(); //<-- this will also map poco.Supervisor.Name = dto.SupervisorName for reverse mapping