Hi all,

I'm trying to build a custom Id generator - there don't seem to be any examples or and the hibernate dtd suggests implementing a default constructor and IIdentifierGenerator and IConfigurable if required.

I get an exception

System.ArgumentNullException: Value cannot be null.
Parameter name: type

It seems the IdentifierGeneratorFactory is not picking up the IType for the generator in:

NHibernate.Id.IdentifierGeneratorFactory.Create(String strategy, IType type, IDictionary parms, Dialect dialect)

Has anyone managed to create a custom Id generator?

Thanks
Oz

Can you please provide full stack trace and mappings?

I'm having the same problem. Here is the code:

Whoops. Forgot to login.

Here's the stack:

{"The 'type' attribute is not declared."}

" at NHibernate.Cfg.Configuration.AddInputStream(Stream xmlInputStream)\r\n at NHibernate.Cfg.Configuration.AddAssembly(Assembly assembly, Boolean skipOrdering)\r\n at NHibernate.Cfg.Configuration.AddAssembly(Assembly assembly)\r\n at NHibernate.Cfg.Configuration.AddAssembly(String assemblyName)\r\n at SurgeryDataGen.Program.Main(String[] args) in D:\\Projects\\Tempus\\DotNetProjects\\Surgery\\src\\SurgeryDataGen\\Program.cs:line 30\r\n at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args)\r\n at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)\r\n at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()\r\n at System.Threading.ThreadHelper.ThreadStart_Context(Object state)\r\n at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)\r\n at System.Threading.ThreadHelper.ThreadStart()"

No, you're not having the same problem :) Your problem is that <generator> doesn't have type attribute.

<generator class="SurgeryHibernate.Domain.PaddedSequenceGenerator" type="String">

It's there?

Yes, you have it there, but it's not allowed.

So where does it go? I used this same algo in Hib3 for Java and it didn't require a type other than in the id tag:

I added that type trying to figure out what it wanted - removed and similar error. The original location for the type is still intact:

<id name="Id" column="key_facili" type="String" unsaved-value="00000000">



{"could not instantiate id generator for strategy 'SurgeryHibernate.Domain.PaddedSequenceGenerator'"}

{"Value cannot be null.\r\nParameter name: type"}

at NHibernate.Id.IdentifierGeneratorFactory.Create(String strategy, IType type, IDictionary parms, Dialect dialect)
at NHibernate.Mapping.SimpleValue.CreateIdentifierGenerator(Dialect dialect)
at NHibernate.Persister.AbstractEntityPersister..ctor(PersistentClass model, ISessionFactoryImplementor factory)
at NHibernate.Persister.EntityPersister..ctor(PersistentClass model, ISessionFactoryImplementor factory)
at NHibernate.Persister.PersisterFactory.CreateClassPersister(PersistentClass model, ISessionFactoryImplementor factory)
at NHibernate.Impl.SessionFactoryImpl..ctor(Configuration cfg, Settings settings)
at NHibernate.Cfg.Configuration.BuildSessionFactory()
at SurgeryDataGen.Program.Main(String[] args) in D:\Projects\Tempus\DotNetProjects\Surgery\src\SurgeryDataGen\Program.cs:line 31
at System.AppDomain.nExecuteAssembly(Assembly assembly, String[] args)
at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()

Ok I fixed the code to throw a more informative exception. You are missing the assembly name in the class="...", so NHibernate can't load the type.

Worked like a charm. Thanks a bunch.