NHibernate Cascade none still updating related entity

Question

I am then using Fluent NHibernate and its automapping feature to map the the following simplified POCO classes:

public class Webpage
{    
public virtual int Id { get; set; }    
public virtual string UrlIdentifier { get; set; }    
public virtual WebpageType WebpageType { get; set; }    
}

public class WebpageType
{    
public virtual int Id { get; set; }    
public virtual string Name { get; set; }       
}

I am then overriding the following mapping to explicitly set no cascading from Webpage to WebpageType:

public class WebpageMap : IAutoMappingOverride<Webpage>
{
    public void Override(AutoMapping<Webpage> mapping)
    {
        mapping.References(w => w.WebpageType).Cascade.None();    
    }
}

For any pur NHibernate readers, here are the xml mappings produced by fluent:

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-access="property" auto-import="true" default-cascade="none" default-lazy="true">
  <class xmlns="urn:nhibernate-mapping-2.2" name="EveryPage.Core.Domain.Webpage, EveryPage.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Webpage`">
    <id name="Id" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" unsaved-value="0">
      <column name="Id" />
      <generator class="identity" />
    </id>
    <property name="UrlIdentifier" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="UrlIdentifier" />
    </property>
    <many-to-one cascade="none" class="EveryPage.Core.Domain.WebpageType, EveryPage.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="WebpageType">
      <column name="WebpageType_id" />
    </many-to-one>    
  </class>
</hibernate-mapping>


<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-access="property" auto-import="true" default-cascade="none" default-lazy="true">
  <class xmlns="urn:nhibernate-mapping-2.2" name="EveryPage.Core.Domain.WebpageType, EveryPage.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`WebpageType`">
    <id name="Id" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" unsaved-value="0">
      <column name="Id" />
      <generator class="identity" />
    </id>
    <property name="Name" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Name" />
    </property>
  </class>
</hibernate-mapping>

The problem comes when I test that updates do not cascade to WebpageType via webpage, basically they do!!

I have the following test:

    [Test]
    public void Assert_SaveOrUpdate_On_Webpage_Does_Not_Cascade_Update_To_WebpageType()
    {
        // Get the existing webpage.
        webpage = _webpageRepository.Get("~/testwebpage1.aspx");

        // Update the WebpageType.
        const string webpageTypeName = "qwerty test";
        webpage.WebpageType.Name = webpageTypeName;

        // Save the changes.
        Assert.DoesNotThrow(() => _webpageRepository.SaveOrUpdate(webpage));

        // We need to flush the changes to the store for it to execute the changes.
        Assert.DoesNotThrow(() => NHibernateSession.Current.Flush());

        // Remove the webpage and tag from the level 1 cache so we force a trip to the store on our next check.
        NHibernateSession.Current.Evict(webpage);

        //  Check that the webpageType has not been updated.
        webpageType = _webpageTypeRepository.Get(webpageType.Id);
        Assert.AreNotEqual(webpageTypeName, webpageType.Name);
    }

The above test is wrapped in a global transaction.

The test fails and NHibernate does execute an update to the Name of the related WebpageType. The delete and save(create new) cascades work correctly and do not cascade.

Have I missunderstood cascade and/or is there a problem with my logic/test.

Any help/advice is appreciated. Thanks.

Answer 1

If you are trying to stop your app from accidentally changing properties on WebPageType, I think it would be easier and safer to achieve this by marking WebPageType as ReadOnly in the mapping. Then you won't need to protect it via handling cascading in all its associations.