Create Multi-Language domain model (dynamic resource) with Nhibernate and database ?

1. Create a Culture Filter on one nhibernate mapping file :

 <?xml version="1.0" encoding="utf-8" ?>  
 <hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" ...>  
  <class ...>  
   ...  
  </class>   
  <filter-def name="CultureFilter">  
    <filter-param name="CultureCode" type="System.String" />  
  </filter-def>    
 </hibernate-mapping>     

2. Declare the following tag of culture code in the mapping files related to the language table :

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping ...>
    <class name="ProductTypeCulture" table="Product_Type_Culture" mutable="false">
       <id name="ID" column="ProductTypeId" type="Int64"  unsaved-value="0" >
      <generator class="native" />
    </id>
    <property name="Label" column="Label" type="String" not-null="true"/>
    <property name="CultureCode" column="CultureCode" type="String" not-null="true"/>
    <filter name="CultureFilter" condition=":CultureCode = CultureCode"/>     
    </class>
</hibernate-mapping>  

3. In the application_beginrequest, you should enable filter on the nhibernate session :

CultureCode = CultureInfo.CurrentCulture.TwoLetterISOLanguageName;
public string CultureCode
{
    get { return CultureInfo.CurrentCulture.TwoLetterISOLanguageName; }
    set
        {
          nhSession.EnableFilter(“CultureFilter”).SetParameter(“CultureCode”,value)
          .Validate();
        }
}

4. Now, the entity ProductTypeCulture should inherit the following class :

 public class EntityCulture : Entity<EntityCulture>, ICloneable, IEntityCulture  
 {  
   #region Constructors  
   public EntityCulture() {}  
   
   public EntityCulture(string label)  
   {  
     _label = label;  
   }  
   #endregion  
   
   #region Properties  
   private string _label;  
   public virtual string CultureCode { get; set; }  
   public virtual string Label  
   {  
     get { return _label; }  
     set { _label = value; }  
   }  
   #endregion  
   
   #region ICloneable Members  
   public virtual object Clone()  
   {  
     var cloned = new EntityCulture {Label = Label};  
     return cloned;  
   }  
   #endregion  
   
   #region override  
   private int? _oldHashCode;  
   public override bool IsTransient()  
   {  
     return ID.Equals(0) || string.IsNullOrEmpty(CultureCode);  
   }  
   public virtual bool Equals(EntityCulture other)  
   {  
     if (ReferenceEquals(this, other))  
       return true;  
   
     if (other == null || !GetType().Equals(other.GetType()))  
       return false;  
   
     if (!IsTransient() && !other.IsTransient() && ID.Equals(other.ID) &&         CultureCode.Equals(other.CultureCode))  
       return true;  
   
     return IsTransient() && other.IsTransient();  
   }  
   
   public override bool Equals(object obj)  
   {  
     var compareTo = obj as EntityCulture;  
   
     return Equals(compareTo);  
   }  
   
   public override int GetHashCode()  
   {  
     if (_oldHashCode.HasValue)  
       return _oldHashCode.Value;  
   
     if (IsTransient())  
     {  
       _oldHashCode = base.GetHashCode();  
       return _oldHashCode.Value;  
     }  
   
     return ID.GetHashCode() + CultureCode.GetHashCode();  
   }  
   
   public override string ToString()  
   {  
     return GetType().FullName + "#" + ID + "-" + CultureCode;  
   }  
   #endregion  
 }  
 public interface IEntityCulture  
 {  
   string Label { get; set; }  
   object Clone();  
 }  
   

5. Finally, the entity ProductType should inherit the following class :

 public class EntityMultiLanguage<T, TCulture> : Entity<T>, IEntityMultiLanguage<TCulture> where T : class where TCulture : class, IEntityCulture  
 {  
   private IDictionary<string, TCulture> _resources;  
   
   #region IEntityMultiLanguage<TCulture> Members  
   public virtual string Label  
   {  
     get  
     {  
       TCulture res = GetResource();  
       return res != null ? res.Label : null;  
     }  
     set  
     {  
       GetOrCreateResource().Label = value;  
     }  
   }  
   
   public virtual IDictionary<string, TCulture> Resources  
   {  
     get { return _resources ?? new Dictionary<string, TCulture>(); }  
     set { _resources = value; }  
   }  
   #endregion  
   
   protected virtual TCulture GetDefaultResource()  
   {  
   return   Resources.ContainsKey(CultureFilter.DefaultCulture.TwoLetterISOLanguageName)  
       ? Resources[CultureFilter.DefaultCulture.TwoLetterISOLanguageName]  
       : null;  
   }  
   
   protected virtual TCulture GetOrCreateResource()  
   {  
     if (Resources.ContainsKey(CultureFilter.CultureCode))  
       return Resources[CultureFilter.CultureCode];  
   
     var newResource = GetResource().Clone() as TCulture;  
     Resources.Add(CultureFilter.CultureCode, newResource);   
     return newResource;  
   }  
   protected virtual TCulture GetResource()  
   {  
     return Resources.ContainsKey(CultureFilter.CultureCode)  
       ? Resources[CultureFilter.CultureCode]  
       : GetDefaultResource();  
   }  
 }