Why does NHibernate require "protected internal" visibility on auto properties?

Question

It used to be possible to map auto properties with private setters with NHibernate, but starting with version 3.2 this is no longer the case (not without replacing the entity validator), see NH dev discussion.

I understand the protected requirement, but why internal? This breaks encapsulation, and just feels dirty.

Is the only alternative going back to backing fields?

UPDATE: Embarassing but true, it turns out internal is not required. So, it's a toss-up between falling back to backing fields or using the protected setter and either avoiding setting values in the constructor or facing the risk of hard to track bugs. Thank you Fabio and @Nexus for pointing out my mistake.

no, I meant why `protected internal` instead of just `protected`, if I can't have `private`. — Michael Teper, May 24 '11 at 18:21

score 6 · Accepted Answer · answered May 25 '11 at 11:09

6

Michael,

public string Foo { get; protected set; } should still be possible, the dev discussion is about public string Foo { get; private set; } which can lead to errors while using lazy properties.

answered May 25 '11 at 11:09

Nexus

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The proxy validator uses MethodBase.IsFamilyOrAssembly so internal OR protected should work but I don't think it needs both. – Danielg May 25 '11 at 14:42
I am pretty sure I tested that, but if you're right, that would be some egg on face. Results in a bit. – Michael Teper May 25 '11 at 15:55
Tested, and updated the question with the results (you were right, thank you!) – Michael Teper May 25 '11 at 16:44

score 1 · Answer 2 · answered May 24 '11 at 18:09

1

NHibernate is quite dirty. It uses reflection in order to access the properties and fields.

You can even map private properties and fields as data points.

NHibernate ignores completely the visibility of the elements it needs to access.

answered May 24 '11 at 18:09

Paulo Santos

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Paulo, how would you map this with NH 3.2: `public string Foo { get; private set; }` ? – Michael Teper May 24 '11 at 18:10
I quite don't remember the code of NHbiernate that queries for the getter and setter of the property. It could be done, but I'm not sure. – Paulo Santos May 24 '11 at 18:12

score 1 · Answer 3 · edited May 20 '13 at 11:53

1

public class Class{

    public string Foo { get; private set; }

}

Property(class=> class.Foo);

You will then need to turn off proxy validation in your configuration:

Config.Proxy(p => {p.Validation = false});

edited May 20 '13 at 11:53

Joel

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answered Dec 21 '11 at 21:08

Timbob

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Why does NHibernate require "protected internal" visibility on auto properties?

3 Answers3