Implementing multi-lingual entities

[ebicoglu]

We have started to implement this feature in the past, but it was canceled due to some design problems.
This issue is for getting ideas from the community and tracking the progress of the this feature.
The previous related conversation is at #1754

This feature exists in ASP.NET Boilerplate and if you don't want to wait and implement it on your own, check out the ASP.NET Boilerplate implementation

• https://github.com/aspnetboilerplate/aspnetboilerplate/tree/dev/src/Abp/Domain/Entities
• https://aspnetboilerplate.com/Pages/Documents/Multi-Lingual-Entities

[rashedjawda]

Thank you, that's good news.
We already implement it in our solutions the same way implemented in aspnetboilerplate, I hope the migration go smoth :)

[julian-forster]

@ebicoglu can you please explain the key design problems, so that we can give you feedback and maybe some ideas for possible solutions?

[angel-sotabytes]

Any new about the progress? I want to buy the abp commercial but this feature is a must for my purpose.

[ahmednfwela]

I have done some progress on this in these 2 PRs

#13384
#14837

and according to this test, there is no need to use sync over async at all!

abp/framework/test/Volo.Abp.MultiLingualObjects.Tests/Volo/Abp/MultiLingualObjects/MultiLingualObjectManager_Tests.cs

Lines 137 to 155 in 8ca3e79

	public async Task TestBulkMapping()
	{
	using (CultureHelper.Use("en-us"))
	{
	var translations = await _multiLingualObjectManager.GetBulkTranslationsAsync<MultiLingualBook, MultiLingualBookTranslation>(_books);
	var translationsDict = translations.ToDictionary(x => x.entity.Id, x => x.translation);
	var mapped = _mapperAccessor.Mapper.Map<List<MultiLingualBook>, List<MultiLingualBookDto>>(_books, options =>
	{
	options.Items.Add(nameof(MultiLingualBookTranslation), translationsDict);
	});
	Assert.Equal(mapped.Count, _books.Count);
	for (int i = 0; i < mapped.Count; i++)
	{
	var og = _books[i];
	var m = mapped[i];
	Assert.Equal(og.Translations.FirstOrDefault(x => x.Language == "en")?.Name, m.Name);
	}
	}
	}

and this is the mapping profile that makes this possible:

abp/framework/test/Volo.Abp.MultiLingualObjects.Tests/Volo/Abp/MultiLingualObjects/MultiLingualObjectTestProfile.cs

Lines 8 to 23 in 8ca3e79

	public class MultiLingualObjectTestProfile : Profile
	{
	public MultiLingualObjectTestProfile()
	{
	CreateMap<MultiLingualBook, MultiLingualBookDto>()
	.ForMember(x => x.Name,
	x => x.MapFrom((src, target, member, context) =>
	{
	if (context.Items.TryGetValue(nameof(MultiLingualBookTranslation), out var translationsRaw) && translationsRaw is IReadOnlyDictionary<Guid, MultiLingualBookTranslation> translations)
	{
	return translations.GetValueOrDefault(src.Id)?.Name;
	}
	return null;
	}));
	}
	}

it uses automapper's ability to pass parameters during the mapping process, see official docs

It would be easier if Abp had this by default, so that we don't have to go through automapper #14834
but it was discarded as an unnecessary feature