adding profiles to automapper after initialisation

Question

having some trouble with adding profiles after some external assembly already added mapperconfiguration on the DI-setup.

first i just added some code to add the profiles

       var mapperConfiguration = new MapperConfiguration(cfg =>
        {
            cfg.AddProfile<DataMappingProfile>();
        });
        mapperConfiguration.AssertConfigurationIsValid();
        services.AddSingleton<IMapper>(new Mapper(mapperConfiguration));

but then i overwrote some other mappingprofiles.

so i was thinking, i should try to add mine to the existing mappingconfiguration.

so i was going this way

        var sp = services.BuildServiceProvider();
        var autoMapper = sp.GetService<IMapper>();
        var mapperConfiguration = autoMapper?.ConfigurationProvider as MapperConfiguration;

        var configuration = new MapperConfigurationExpression();
        configuration.AddProfile<LpisMappingProfile>();


        if (mapperConfiguration == null)
        {
            mapperConfiguration = new MapperConfiguration(configuration);
        }
        else
        {
            //add the previous as well
            //?? add this `configuration` ?
        }

        mapperConfiguration.AssertConfigurationIsValid();
        services.AddSingleton<IMapper>(new Mapper(mapperConfiguration));

but i am a little stuck on the else flow. Any advice?

thnx!

Answer 1

That's not possible. If an assembly uses a private MapperConfiguration, then that's its own business. If it wants to collaborate with the app, it should not define a MapperConfiguration, it should define profiles to be scanned by the app and added to the singleton MapperConfiguration owned by the app. The AM configuration is read-only, after the init phase it's not possible to change it.