NHibernate的Alias​​ToBean变压器协会 [英] NHibernate AliasToBean transformer associations

问题描述

我想用下面的语句来获取与域的实体后，我：

I'm trying to use the following statement to get an entity with the fields I'm after:

retVal = session.CreateCriteria(typeof(MyEntity))
            .CreateAlias("MyEntityProperty", "MyEntityProperty")
            .Add(Restrictions.Eq("MyEntityProperty.Year", year))
            .SetProjection(
                Projections.Distinct(
                    Projections.ProjectionList()
                        .Add(Projections.Property("Property1"), "Property1")
                        .Add(Projections.Property("Property2"), "Property2")
                        .Add(Projections.Property("MyEntityProperty.RegisteredUser"), "MyEntityProperty.RegisteredUser")
                        .Add(Projections.Property("MyEntityProperty.CompanyInfo"), "MyEntityProperty.CompanyInfo")
                                                )
            )
            .SetResultTransformer(Transformers.AliasToBean(typeof(MyEntity)))
            .List<MyEntity>()
            .Cast<BaseMyEntity>();

myEntity所是我要回的实体，MyEntityProperty是myEntity所的属性是（类型MyEntityProperty的）另一个实体。

MyEntity is the entity I want to return, and MyEntityProperty is a property of MyEntity that is another entity (of type MyEntityProperty).

我得到的错误是找不到在类属性MyEntityProperty.RegisteredUser'二传手'myEntity所

是Alias​​ToBean变压器无法处理子实体？或者是有更多的东西，我需要做的，使工作？

Is the AliasToBean transformer not able to handle sub entities? Or is there something more I need to do to make it work?

推荐答案

还有就是我的力作的...我使用变换预测任意的深度其中。把它和使用它是这样的：

There is my master piece... which I'm using to transform any level of projections depth. Take it and use it like this:

.SetResultTransformer(new DeepTransformer<MyEntity>())

它可以用于任何值类型属性，多到一引用和也的动态对象 ...

It could be used for any ValueType properties, many-to-one references and also for dynamic objects...

public class DeepTransformer<TEntity> : IResultTransformer
    where TEntity : class
{
    // rows iterator
    public object TransformTuple(object[] tuple, string[] aliases)
    {
        var list = new List<string>(aliases);

        var propertyAliases = new List<string>(list);
        var complexAliases = new List<string>();

        for(var i = 0; i < list.Count; i++)
        {
            var aliase = list[i];
            // Aliase with the '.' represents complex IPersistentEntity chain
            if (aliase.Contains('.'))
            {
                complexAliases.Add(aliase);
                propertyAliases[i] = null;
            }
        }

        // be smart use what is already available
        // the standard properties string, valueTypes
        var result = Transformers
             .AliasToBean<TEntity>()
             .TransformTuple(tuple, propertyAliases.ToArray());

        TransformPersistentChain(tuple, complexAliases, result, list);

        return result;
    }

    /// <summary>Iterates the Path Client.Address.City.Code </summary>
    protected virtual void TransformPersistentChain(object[] tuple
          , List<string> complexAliases, object result, List<string> list)
    {
        var entity = result as TEntity;

        foreach (var aliase in complexAliases)
        {
            // the value in a tuple by index of current Aliase
            var index = list.IndexOf(aliase);
            var value = tuple[index];
            if (value.IsNull())
            {
                continue;
            }

            // split the Path into separated parts
            var parts = aliase.Split('.');
            var name = parts[0];

            var propertyInfo = entity.GetType()
                  .GetProperty(name, BindingFlags.NonPublic 
                                   | BindingFlags.Instance 
                                   | BindingFlags.Public);

            object currentObject = entity;

            var current = 1;
            while (current < parts.Length)
            {
                name = parts[current];
                object instance = propertyInfo.GetValue(currentObject);
                if (instance.IsNull())
                {
                    instance = Activator.CreateInstance(propertyInfo.PropertyType);
                    propertyInfo.SetValue(currentObject, instance);
                }

                propertyInfo = propertyInfo.PropertyType.GetProperty(name, BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public);
                currentObject = instance;
                current++;
            }

            // even dynamic objects could be injected this way
            var dictionary = currentObject as IDictionary;
            if (dictionary.Is())
            {
                dictionary[name] = value;
            }
            else
            {
                propertyInfo.SetValue(currentObject, value);
            }
        }
    }

    // convert to DISTINCT list with populated Fields
    public System.Collections.IList TransformList(System.Collections.IList collection)
    {
        var results = Transformers.AliasToBean<TEntity>().TransformList(collection);
        return results;
    }
}

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