I am new to NHibernate but loved it already. I ran into a problem with the mapping. I have a class that contains a System.Net.Mail.MailAddress object. I am trying to map it as a component of the parent class. How do I tell NHibernate the class of MailAddress?
I tried the following but not working:
<component name ="Sender" class="System.Net.Mail.MailAddress" >
<property name="Address" column="Sender" type="string" length="50" />
<property name="DisplayName" column="SenderName" type="string" length="50" />
</component>

any response will be greatly appreciated!

Please elaborate on how it is not working. Information such as exception message and stack trace will help people help you. At any rate, I believe the class used for a component must have a default constructor, and System.Net.Mail.MailAddress does not have one.

Karl, thank you for your reply. actually, it didn't even go that far, the mapping file could not be compiled with the following error:

{"could not find class: System.Net.Mail.MailAddress"}

The stack trace:

at NHibernate.Cfg.HbmBinder.ClassForFullNameChecked(String fullName, String errorMessage)
at NHibernate.Cfg.HbmBinder.ClassForNameChecked(String name, Mappings mappings, String errorMessage)
at NHibernate.Cfg.HbmBinder.GetPropertyType(XmlNode definingNode, Mappings mappings, Type containingType, String propertyName)
at NHibernate.Cfg.HbmBinder.PropertiesFromXML(XmlNode node, PersistentClass model, Mappings mappings)
at NHibernate.Cfg.HbmBinder.BindRootClass(XmlNode node, RootClass model, Mappings mappings)
at NHibernate.Cfg.HbmBinder.BindRoot(XmlDocument doc, Mappings mappings)
at NHibernate.Cfg.Configuration.AddValidatedDocument(XmlDocument doc, String name)



I also tried to remove the class="System.Net.Mail.MailAddress" part and got the following error:

"Could not find a setter for property 'Address' in class 'System.Net.Mail.MailAddress'"

with stack trace:
at NHibernate.Property.BasicPropertyAccessor.GetSetter(Type type, String propertyName)
at NHibernate.Mapping.Property.GetSetter(Type clazz)
at NHibernate.Cfg.HbmBinder.BindComponent(XmlNode node, Component model, Type reflectedClass, String className, String path, Boolean isNullable, Mappings mappings)
at NHibernate.Cfg.HbmBinder.PropertiesFromXML(XmlNode node, PersistentClass model, Mappings mappings)
at NHibernate.Cfg.HbmBinder.BindRootClass(XmlNode node, RootClass model, Mappings mappings)
at NHibernate.Cfg.HbmBinder.BindRoot(XmlDocument doc, Mappings mappings)
at NHibernate.Cfg.Configuration.AddValidatedDocument(XmlDocument doc, String name)

There is no setter for the Address property, therefore, unless you know the underlying field name (if it even uses one), you cannot get NHibernate to map to it.

Based on the problem with the Address property and the fact that MailAddress does not have a default constructor, it may not be the best of ideas to map directly to the MailAddress class. My suggestion is to map to a couple of private fields and then create helper methods or accessors to get and set the Sender property. What you lose from doing that is the ability to query on that property like this:

Instead, you will have to write this (assuming the field name is senderDisplayName):

An alternative is to extend the MailAddress class and give it what it is missing. I would advise against it though.

Thank you so much Karl. You have pointed me to the right direction.