设置nHibernate以获取翻译

Question

Im trying to set up NHibernate to get translations depending on witch languageId i provide.

I have a class that look something like this:

public class Location
{
    public virtual Guid Id { get; set; }

    [Translate("Name")]
    public virtual string Name { get; set; }

    [Translate("Description")]
    public virtual string Description { get; set; }

    public virtual bool Popular { get; set; }
    public virtual bool Active { get; set; }
}

My Translate Attribute looks like this:

[AttributeUsage(AttributeTargets.Property)]
public class TranslateAttribute : Attribute
{
    public readonly string DatabaseSuffix;

    public TranslateAttribute(string databaseSuffix)
    {
        DatabaseSuffix = databaseSuffix;
    }

    public string GetSuffix()
    {
        return DatabaseSuffix;
    }
}

I also have a thing that know what Language i am currently using:

public interface ILanguageProvider
{
    void SetLanguage(string language);
    string GetCurrentLanguage();
}

I would like to setup nhibernate with conventions so when fetching anything that has a property that has the Translate-attribute it should Query against my Translations-table like this for each property (or maybe get all translations at once):

SELECT TOP 1 Text 
FROM Translations 
WHERE Id = '{Id_From_my_Entity}_DataBaseSuffixFromTheTranslationAttribute' AND
      LanguageId = LanguageIdFromGetCurrentLanguageInTheImplentationOFILanguageProvider;

And set the result it gets back to its property it is getting the translation for.

Is this possible? and how do i implement this?

Im using nHibernate 3.3.1.4000 and Fluent NHibernate 1.3.0.733

Answer 1

i would not do this magically.

use a dictionary and a property which gives the current name. This has the advantage that if the language is changed all objects will have the correct translation available.

public class MyClass1
{
    protected virtual IDictionary<string, string> Names { get; private set; }

    public virtual string Name { get { return Names[GetCurrentLanguageFromSomeWhere()]; } }
}


public class MyClass1Map : ClassMap<MyClass1>
{
    public MyClass1Map()
    {
        [...]
        HasMany(mc => mc.Names)
            .Table("Translations")
            .Where("property == 'Name'")
            .AsMap("language")
            .Element("text")
            .Not.LazyLoad();

        HasMany(mc => mc.Descriptions)
            .Table("Translations")
            .Where("property == 'Description'")
            .AsMap("language")
            .Element("text")
            .Not.LazyLoad();
    }
}

or use a Formula if the language is static

Map(mc => mc.Name).Formula("... WHERE Language=" + GetCurrentLanguage());