The guidance given here http://fluentnhibernate.org/blog/2010/05/23/feature-focus-fields.html suggests that from V1.1 the automapping feature of Fluent NHibernate supports mapping to private fields.
So given the following code, NHiberate should be able to map to the myValue field.
public class SomeEntity
{
private string myValue;
public virtual int Id { get; set; }
}
public class DomainAutomappingConfiguration : DefaultAutomappingConfiguration
{
public override bool ShouldMap(FluentNHibernate.Member member)
{
return (member.IsProperty && member.IsPublic && member.CanWrite) ||
(member.IsField && member.IsPrivate);
}
}
However when I run this code and try to map, I get the following exception:
NHibernate.PropertyNotFoundException : Could not find a getter for property 'myValue' in
class.....
I am using FluentNHibernate 1.1 and NHibernate 3.0.0.2001
What am I doing wrong?
Change:
private string myValue;
To:
private string myValue {get;set;}
I am not sure if this will do it for you, but the error you are receiving is the lack of the {get;} when designating the private field. Hopefully this will put you on the right track. I have not tried mapping private fields.
Good luck.
Related
With FluentNHibernate I have mapped a UserPreference entity which references the GeneralPreference, GeneralPreferenceOption, and Profile entities:
public class UserPreference
{
public virtual long Id { get; set; }
public virtual Profile Profile { get; set; }
public virtual GeneralPreference Preference { get; set; }
public virtual GeneralPreferenceOption Value { get; set; }
}
It's easy enough to map a list of UserPreference on my Profile entity, but what I actually would like to do is wrap this list inside another class so that I can simplify operations concerning a user's given preferences:
public class Preferences
{
public IList<UserPreferences> UserPreferences{get;set;}
public Language Language {
{
//look up the language preference here
}
}
This kind of feels like a Component, but Components were not created for this type of scenario. Does anyone have any pointers on how I might map this?
I figured out a way to do this by mapping a private property on my Profile Entity. Using the techniques from the Fluent NHibernate wiki on mapping private properties (http://wiki.fluentnhibernate.org/Fluent_mapping_private_properties) I map a collection of UserPreference on my Profile Entity. Then I create another class PropertyHandler which takes an IEnumerable as a constructor parameter and make an instance of this a public property on Profile as well:
public class Profile
{
private PreferenceHandler _preferenceHandler;
get { return _preferenceHandler ?? (_preferenceHandler = new PreferenceHandler(UserPreferences)); }
private IEnumerable<UserPreference> UserPreferences { get; set; }
public static class Expressions
{
public static readonly Expression<Func<Profile, IEnumerable<UserPreference>>> UserPreferences = x => x.UserPreferences;
}
}
Notice the nested static class. It's used to enable mapping of a private property with FluentNHibernate.
The mapping class looks something like this:
public class ProfileMappings : ClassMap<Profile>
{
public ProfileMappings()
{
//... other mappings
HasMany(Profile.Expressions.UserPreferences);
}
}
I can now use the PreferenceHandler class to create helper methods over my collection of UserPreference.
An alternative is to build extension methods for IEnumberable. This works, but I decided not to do this because
1) I'm not really extending the IEnumerable functionality and
2) my helper methods disappear inamongst all the other IEnumerable extension methods making the whole thing a bit cluttered.
I know this question has been raised in similar form multiple times, but none of the threads could give me the concrete answer to my question.
I use Fluent NHibernate and Fluent`s auto-mapping to map my domain entities. Right now, I use this convention class to set all properties NOT NULL:
public class NotNullColumnConvention : IPropertyConvention
{
public void Apply(FluentNHibernate.Conventions.Instances.IPropertyInstance instance)
{
instance.Not.Nullable();
}
}
The big question is:
What do I need to do, to allow single properties of my entity classes to be NULL?
Here is one of my entity classes:
public class Employee : Entity
{
public virtual string FirstName { get; set; }
public virtual string LastName { get; set; }
}
I´d be really pleased, if someone can finally help me out! All possible search string I have entered into Google return pages, marked as already visited...
Thanks,
Arne
EDIT: Changed title ... Want to allow NULL for single properties
Create an attribute :
[AttributeUsage(AttributeTargets.Property, AllowMultiple = false)]
public class CanBeNullAttribute : Attribute
{
}
And a convention :
public class CanBeNullPropertyConvention : IPropertyConvention, IPropertyConventionAcceptance
{
public void Accept(IAcceptanceCriteria<IPropertyInspector> criteria)
{
criteria.Expect(
x => !this.IsNullableProperty(x)
|| x.Property.MemberInfo.GetCustomAttributes(typeof(CanBeNullAttribute), true).Length > 0);
}
public void Apply(IPropertyInstance instance)
{
instance.Nullable();
}
private bool IsNullableProperty(IExposedThroughPropertyInspector target)
{
var type = target.Property.PropertyType;
return type.Equals(typeof(string)) || (type.IsGenericType && type.GetGenericTypeDefinition().Equals(typeof(Nullable<>)));
}
}
Drop the attribute on top of your properties.
I am trying to map my collections with FNHib automapping. The problems that I want to solve are:
1) I want all my collections in the project to be mapped via private field. How can I say that globally?
2) Is there any way to automap bidirectional relationship without explicitly overriding each of my entities.
class OrganizationEntity example:
private ISet<> _collectionWarehouse;
public virtual IEnumerable<WarehouseEntity> CollectionWarehouse
{
get{return _collectionWarehouse; }
set{_collectionWarehouse = new HashedSet<WarehouseEntity>((ICollection<WarehouseEntity>)value)}
}
Class WarehouseEntity example:
public virtual OrganizationEntity Organization{get;set;}
You can map your collections to a private field 'globally' with the following convention:
// assumes camel case underscore field (i.e., _mySet)
public class CollectionAccessConvention : ICollectionConvention
{
public void Apply(ICollectionInstance instance) {
instance.Access.CamelCaseField(CamelCasePrefix.Underscore);
}
}
Whenever you want to set a 'global' automap preference in FNH, think conventions. The you use the IAutoOverride on a given class map if you need to.
As far has the set (a HashSet is usually what I really want also) part, the last time I had to do some mapping, I did need to do an override, like:
public class ActivityBaseMap : IAutoMappingOverride<ActivityBase>
{
public void Override(AutoMapping<ActivityBase> m)
{
...
m.HasMany(x => x.Allocations).AsSet().Inverse();
}
}
I do agree that should translate into a convention though, and maybe you can do that these days. Please post if you figure it out.
HTH,
Berryl
CODE TO USE A HASHSET as an ICollection =================
public virtual ICollection<WarehouseEntity> Wharehouses
{
get { return _warehouses ?? (_warehouses = new HashSet<WarehouseEntity>()); }
set { _warehouses = value; }
}
private ICollection<WarehouseEntity> _warehouses;
I have the following idea:
Business object implemented as interface or abstract class with certain properties as read only to all layers except the DAL layer. I also want my business objects in another assembly than the DAL (for testing purposes), so marking the properties is not an option for me.
Examples could be one to one relationships or other properties.
I have almost solved the issue by doing the following
abstract class User
{
public virtual long UserId {get; protected set;}
public virtual string Password {get; protected set;}
...
}
In the DAL:
public class DbUser : User
{
internal virtual void SetPassword(string password) {...}
}
I then map this using fluent as
ClassMap<User> {...}
SubclassMap<DbUser> {...}
The problem I get is that fluent tries to create a table named DbUser.
If I skip the SubclassMap and creates a DbUser object and tries to save it I get an "No persister for this object" error.
Is it possible to solve?
You could probably override what is done with Fluent
public class DbUser: IAutoMappingOverride<DbUser>
{
public void Override(AutoMapping<DbUser> mapping)
{
//tell it to do nothing now, probably tell it not to map to table,
// not 100% on how you'd do this here.
}
}
Or you could have an attribute
public class DoNotAutoPersistAttribute : Attribute
{
}
And in AutoPersistenceModelGenerator read for attribute in Where clause to exclude it.
Check would be something like
private static bool CheckPeristance(Type t) {
var attributes = t.GetCustomAttributes(typeof (DoNotAutoPersistAttribute), true);
Check.Ensure(attributes.Length<=1, "The number of DoNotAutoPersistAttribute can only be less than or equal to 1");
if (attributes.Length == 0)
return false;
var persist = attributes[0] as DoNotAutoPersistAttribute;
return persist == null;
}
Then it kind of depends how you're adding entities but you're probably adding via assembly so this might do it for you:
mappings.AddEntityAssembly(typeof(User).Assembly).Where(GetAutoMappingFilter);
....
...
private static bool GetAutoMappingFilter(Type t)
{
return t.GetInterfaces().Any(x => CheckPeristance(x)); //you'd probably have a few filters here
}
Is there a way to persist an enum to the DB using NHibernate? That is have a table of both the code and the name of each value in the enum.
I want to keep the enum without an entity, but still have a foreign key (the int representation of the enum) from all other referencing entities to the enum's table.
Why are you guys over complicating this? It is really simple.
The mapping looks like this:
<property name="OrganizationType"></property>
The model property looks like this:
public virtual OrganizationTypes OrganizationType { get; set; }
The Enum looks like this:
public enum OrganizationTypes
{
NonProfit = 1,
ForProfit = 2
}
NHibernate will automatically figure it all out. Why type more than you need????
You can use the enum type directly: http://web.archive.org/web/20100225131716/http://graysmatter.codivation.com/post/Justice-Grays-NHibernate-War-Stories-Dont-Use-Int-If-You-Mean-Enum.aspx. If your underlying type is a string, it should use the string representation, if it is numeric, it will just use the numeric representation.
But your question wording sounds like you're looking for something different, not quite an enum. It seems that you want a lookup table without creating a separate entity class. I don't think this can be done without creating a separate entity class though.
An easy but not so beautiful solution:
Create an integer field with and set the mapping in the mapping file to the field.
Create a public property that uses the integer field.
private int myField;
public virtual MyEnum MyProperty
{
get { return (MyEnum)myField; }
set { myField = value; }
}
I am using NHibernate 3.2, and this works great:
type="NHibernate.Type.EnumStringType`1[[enum_full_type_name, enum_assembly]], NHibernate"
Not sure when the generic EnumStringType got added, though.
Try using a stategy pattern. Uou can then put logic into your inner classes. I use this quite alot espically when there is logic that should be contained in the "enum". For example the code below has the abstract IsReadyForSubmission() which is then implemented in each of the nested subclasses (only one shown). HTH
[Serializable]
public abstract partial class TimesheetStatus : IHasIdentity<int>
{
public static readonly TimesheetStatus NotEntered = new NotEnteredTimesheetStatus();
public static readonly TimesheetStatus Draft = new DraftTimesheetStatus();
public static readonly TimesheetStatus Submitted = new SubmittedTimesheetStatus();
//etc
public abstract int Id { get; protected set; }
public abstract string Description { get; protected set; }
public abstract bool IsReadyForSubmission();
protected class NotEnteredTimesheetStatus: TimesheetStatus
{
private const string DESCRIPTION = "NotEntered";
private const int ID = 0;
public override int Id
{
get { return ID; }
protected set { if (value != ID)throw new InvalidOperationException("ID for NotEnteredTimesheetStatus must be " + ID); }
}
public override string Description
{
get { return DESCRIPTION; }
protected set { if (value != DESCRIPTION)throw new InvalidOperationException("The description for NotEnteredTimesheetStatus must be " + DESCRIPTION); }
}
public override bool IsReadyForSubmission()
{
return false;
}
}
//etc
}