I've been developing with NHibernate with a lot of success; however, I am running into trouble when incorporating the GAC.

I have a dll containing my domain and DAOs. An application layer makes use of this domain layer. I want to register the domain layer dll and nhibernate in the GAC. My application can find the DAO dll; however, when the DAO initializes NHibernate, NHibernate fails to find the domain objects (even though they are in the calling DAO assembly), saying it can't find the file.

I think I understand why this doesn't work. NHibernate is using the class name in the mapping file and finds that class via reflection. Since my mapping file is using the partial assembly name (i.e. not the version # and public key), it doesn't search the GAC.

However, I don't know how to work around this (besides not using the GAC). The version number is assigned automatically in the build process, so I don't have the full name available at compiletime. Even if I did, it seems like extreme overkill to have to modify dozens of mapping files on each deployment.


Has anyone else tackled this problem? One method that I thought might be possible would be to modify the embedded xml mapping files at runtime (before instantiating NHibernate, I would do a find/replace on the mapping files). Would this be possible?

I also thought using ILMerge might help, although I haven't tried that yet. I would merge NHibernate with my Domain assembly. Perhaps NHibernate wouldn't even need the partial assemblyname for this. Has anyone tried this? Would there be any sideeffects with regard to how NHibernate accesses the properties/fields on the objects?

Lastly, since I would assume most NHibernate users have their domain objects stored in one assembly, would there be any way to tell nhibernate to search in the calling assembly if none is specified? If not, maybe this would be a worthwhile addition. Even if most users don't put their dlls in the GAC, they could still cleanup their mapping files by not having to specify the assembly in each file.

Even if users don't keep all their domain objects in one assembly, it makes sense that the assembly containing the embedded xml would also contain the objects themselves in nearly all cases. Perhaps NHibernate should default the assembly of an associated object to the assembly containing the object's mapping file.


Thanks for any suggestions,
Trisk

Hi, I'm having the exact same problem, was wondering if anyone had a solution to it.

I was initially thinking of using the NHibernate.Mapping.Attributes but wanted to investiage other options before spending time on that one.

Any information on how to deploy a Domain Layer Assembly that uses NHibernate into the GAC would be appreicated.

Thanks,

Shane

Maybe NHibernate could have an additional configurations possibility, something like "AssemblyNameSubstitutionMap". When loading HBM files, the assembly name used in mapping would be searched from SubstitutionMap, and if found, the value in map would be used instead. Seems quite trivial to implement....

Gert