Version: Next

Translation server side

This file explains what to add the translation on some fields on an existing entity.

Prerequisite

Knowledge to have:

Different possible approach

Within the framework of the BIA, the chosen approach is Separate translation table approach : In this approach Instead of putting all translation under the same table, we will write a separate translation table for each table which requires localization.

Database Internationalization

Implementation

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Create the translation table entity in Domain/TranslationModule/Aggregate.

it should contain :

an id
a link on language (Language + LanguageId)
a link on the entity to translate (Notification + NotificationId in this example)
the fields to translate (Title + Description in this example).

    /// <summary>
/// The role entity.
/// </summary>
public class NotificationTranslation : VersionedTable, IEntity
{
    /// <summary>
    /// Gets or sets the id.
    /// </summary>
    public int Id { get; set; }

    /// <summary>
    /// Gets or sets the language.
    /// </summary>
    public Language Language { get; set; }

    /// <summary>
    /// Gets or sets the language id.
    /// </summary>
    public int LanguageId { get; set; }

    /// <summary>
    ///  Gets or sets the notification type.
    /// </summary>
    public Notification Notification { get; set; }

    /// <summary>
    /// Gets or sets the notification type id.
    /// </summary>
    public int NotificationId { get; set; }

    /// <summary>
    /// Gets or sets the title translated.
    /// </summary>
    public string Title { get; set; }

    /// <summary>
    /// Gets or sets the description translated.
    /// </summary>
    public string Description { get; set; }
}

Add the function to define the model with constraint (and Data if required) in Infrastructure.Data/ModelsBuilders/TranslationModelBuilder.cs

it should contain :

the HasKey(r => r.Id)
the required constraint on LanguageId and the entity to translate id (NotificationId in this example)
the HasIndex on those 2 keys (to avoid duplication of translation on same language and same entity)
the constraint on fields to translate. it should be identical to the constraints in the entity required or not, length... (Title + Description in this example).

        /// <summary>
    /// Create the model for notification.
    /// </summary>
    /// <param name="modelBuilder">The model builder.</param>
    private static void CreateNotificationTranslationModel(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<NotificationTranslation>().HasKey(r => r.Id);
        modelBuilder.Entity<NotificationTranslation>().Property(r => r.NotificationId).IsRequired();
        modelBuilder.Entity<NotificationTranslation>().Property(r => r.LanguageId).IsRequired();
        modelBuilder.Entity<NotificationTranslation>().HasIndex(u => new { u.NotificationId, u.LanguageId }).IsUnique();

        modelBuilder.Entity<NotificationTranslation>().Property(m => m.Title).IsRequired().HasMaxLength(100);
        modelBuilder.Entity<NotificationTranslation>().Property(m => m.Description).IsRequired().HasMaxLength(256);
    }

in case of data to enter at migration add the translation in all language in this function:

increment the id of 100 when changing of entity (in case of adding language in the future)
example of adding notification Type translation in French, spanish and german.

        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 1, LanguageId = LanguageId.French, Id = 101, Label = "Tâche" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 1, LanguageId = LanguageId.Spanish, Id = 102, Label = "Tarea" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 1, LanguageId = LanguageId.German, Id = 103, Label = "Aufgabe" });

        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 2, LanguageId = LanguageId.French, Id = 201, Label = "Information" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 2, LanguageId = LanguageId.Spanish, Id = 202, Label = "Información" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 2, LanguageId = LanguageId.German, Id = 203, Label = "Information" });

        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 3, LanguageId = LanguageId.French, Id = 301, Label = "Succès" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 3, LanguageId = LanguageId.Spanish, Id = 302, Label = "Éxito" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 3, LanguageId = LanguageId.German, Id = 303, Label = "Erfolg" });

        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 4, LanguageId = LanguageId.French, Id = 401, Label = "Avertissement" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 4, LanguageId = LanguageId.Spanish, Id = 402, Label = "Advertencia" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 4, LanguageId = LanguageId.German, Id = 403, Label = "Erwärmen" });

        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 5, LanguageId = LanguageId.French, Id = 501, Label = "Erreur" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 5, LanguageId = LanguageId.Spanish, Id = 502, Label = "Culpa" });
        modelBuilder.Entity<NotificationTypeTranslation>().HasData(new NotificationTypeTranslation { NotificationTypeId = 5, LanguageId = LanguageId.German, Id = 503, Label = "Fehler" });

Add the User Context initialization in service constructor. ex in role service:

    /// <summary>
    /// Initializes a new instance of the <see cref="RoleAppService"/> class.
    /// </summary>
    /// <param name="repository">The repository.</param>
    /// <param name="principal">The principal.</param>
    public RoleAppService(ITGenericRepository<Role> repository, IPrincipal principal, UserContext userContext)
        : base(repository)
    {
        this.principal = principal as BIAClaimsPrincipal;
        this.userContext = userContext;
    }

Adapt the dto (if not optionDto)

add translated fields:

      /// <summary>
    /// Gets or sets the title.
    /// </summary>
    public string Title { get; set; }

    /// <summary>
    /// Gets or sets the title translated.
    /// </summary>
    public string TitleTranslated { get; set; }

    /// <summary>
    /// Gets or sets the description.
    /// </summary>
    public string Description { get; set; }

    /// <summary>
    /// Gets or sets the description translated.
    /// </summary>
    public string DescriptionTranslated { get; set; }

Adapt the mapper:

ex for an optionDto in EntityToDto():

without translation

    Display = entity.Label,

with translation

    Display = entity.RoleTranslations.Where(rt => rt.Language.Code == this.UserContext.Language).Select(rt => rt.Label).FirstOrDefault() ?? entity.Label,

for an entity display in CRUD
translate for sort and filter in ExpressionCollection<Notification>
for display in EntityToDto() add :

    TitleTranslated = entity.NotificationTranslations.Where(rt => rt.Language.Code == this.UserContext.Language).Select(rt => rt.Title).FirstOrDefault() ?? entity.Title,
    DescriptionTranslated = entity.NotificationTranslations.Where(rt => rt.Language.Code == this.UserContext.Language).Select(rt => rt.Description).FirstOrDefault() ?? entity.Description,

for item only ( if (mapperMode == MapperMode.Item)) retrieve all translation (see example in NotificationMapper):

        NotificationTranslations = entity.NotificationTranslations.Select(nt => new NotificationTranslationDto
        {
            DtoState = DtoState.Unchanged,
            Id = nt.Id,
            LanguageId = nt.LanguageId,
            Title = nt.Title,
            Description = nt.Description,
        }).ToList(),

Prerequisite​

Knowledge to have:​

Implementation​

Back​

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Prerequisite

Knowledge to have:

Implementation

Back

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