I am struggling with this issue:
I have a list of NHibernate objects called "Project". These objects contain a lazy - loaded list of "Branches". I am trying to pass a list of Projects to a WCF service so I am using AutoMapper to transform them to flat objects.
The problem is that even though the destination objects called "ProjectContract" does not contain a list of Branches, Automapper still invokes this collection and a lot of queries are made to the database because NHibernate fires the lazy - loading and loads the Branches collection for each project.
Here are the classes and the mapping:
public class Project
{
public virtual int ID
{
get;
set;
}
public virtual string Name { get; set; }
public virtual string Description { get; set; }
public virtual IList<Branch> Branches { get; set; }
}
[DataContract]
public class ProjectContract
{
[DataMember]
public virtual int ID
{
get;
set;
}
[DataMember]
public virtual string Name { get; set; }
[DataMember]
public virtual string Description { get; set; }
}
public class ProjectMappings : Profile
{
protected override void Configure()
{
Mapper.CreateMap<Project, ProjectContract>();
}
}
My question is: Is there a way to tell AutoMapper to not touch the "Branches" collection because I don't care about it and that is a proxy that will trigger many database calls?
I temporarily fixed this with MaxDepth(0), but there are other entities where I have collections that I want to transfer, and collections that I don't want to be touched, like this one. In that case, MaxDepth(0) will not work.
Thank you,
Cosmin
Yes, The AutoMapper Ignore function.
Mapper.CreateMap<Source, Destination>()
.ForMember(dest => dest.SomeValuefff, opt => opt.Ignore());
Related
Yes, this is ANOTHER "Automapper not mapping" question. Either something broke or I'm going the stupid way about it. I'm building a webapp with ASP.NET Core 2.1 using AutoMapper 3.2.0 (latest stable release at the time) though I have tested with 3.1.0 with no luck either.
Question
Simple object to be mapped to another. For the sake of testing and trials, these are now EXACTLY the same, yet still automapper gives:
AutoMapperMappingException: Missing type map configuration or unsupported mapping.
Mapping types:
NotificationModel -> NotificationViewModel
ProjectName.Models.Dashboard.NotificationModel -> ProjectName.Models.Dashboard.NotificationViewModel
The strange thing is, I have previously mapped this model set 7 ways to sunday in the Startup.cs file with the only thing changing is my facial expression. Other maps work as indicated using similar, if not the same code for them.
The Models
NotificationModel.cs
public class NotificationModel
{
public int Id { get; set; }
public string Content { get; set; }
public DateTime CreateTS { get; set; }
public bool FlagRead { get; set; }
public bool FlagSticky { get; set; }
public bool FlagReceipt { get; set; }
public string ReceiptContact { get; set; }
public string UserId { get; set; }
public bool CANCELLED { get; set; }
}
NotificationViewModel.cs
public class NotificationViewModel
{
public int Id { get; set; }
//Reminder, this model has been amended to exactly represent that of the original model for testing purposes.
public string Content { get; set; }
public DateTime CreateTS { get; set; }
public bool FlagRead { get; set; }
public bool FlagSticky { get; set; }
public bool FlagReceipt { get; set; }
public string ReceiptContact { get; set; }
public string UserId { get; set; }
public bool CANCELLED { get; set; }
}
Startup & Automapper Config
Mapper.Initialize(cfg =>
{
// Some other mappings removed for clarity.
cfg.CreateMap<GroupViewModel, GroupModel>().ReverseMap();
//cfg.CreateMap<EntityViewModel, EntityModel>().ReverseMap().ForAllOtherMembers(opt => opt.Ignore());
cfg.CreateMap<NotificationModel, NotificationViewModel>().ForAllMembers(opt => opt.Ignore());
cfg.CreateMap(typeof(NotificationViewModel), typeof(NotificationModel));
//I even left out the .ReverseMap, for testing purposes.
});
Mapper.AssertConfigurationIsValid();
Usage
NotificationViewModel test = _mapper.Map<NotificationViewModel>(item); << Which is where I receive the exception.
Other Attempts
Ok, so I've been through some more articles explaining different things and subsequently tried the following respectively:
cfg.CreateMap(typeof(NotificationModel), typeof(NotificationViewModel));
cfg.CreateMap<NotificationModel, NotificationViewModel>().ReverseMap().ForAllMembers(opt => opt.Ignore());
cfg.CreateMap<NotificationModel, NotificationViewModel>().ForAllOtherMembers(opt => opt.Ignore());
Along with:
NotificationViewModel test = _mapper.Map<NotificationViewModel>(item);
_mapper.Map(item, typeof(NotificationViewModel), typeof(NotificationModel));
NotificationViewModel existingDestinationObject = new NotificationViewModel();
_mapper.Map<NotificationModel, NotificationViewModel>(item, existingDestinationObject);
I've tried amending the .Map()/.Map<> usage several ways, none of which seemed to yield anything but an exception about not having been configured.
So short of manually writing a conversion for this object (which is simple enough for its purpose), I am in dire need of a solution here. If not to use, then atleast to learn from and help others facing the same.
UPDATE
IT WORKS!
Scanning through the project, I noticed that somewhere in previous documentation - I read about creating a type of "config" class that just inherits from an abstract class called Profile. In this class you will also be able to define your maps, yet what is strange is that I am not able to drop this class and simply use the config maps setup in my Startup.cs file. Automapper will refuse to hold any maps that are not defined in this separate class. The below seems to get me what I need, however I still need an explanation as to why Automapper doesn't function as desired without it:
public class AMConfig : Profile
{
public AMConfig()
{
CreateMap<ManageUserModel, IndexViewModel>();
CreateMap<IndexViewModel, ManageUserModel>();
CreateMap<NotificationViewModel, NotificationModel>().ReverseMap();
CreateMap<List<NotificationViewModel>, List<NotificationModel>>().ReverseMap();
CreateMap<TaskViewModel, TaskModel>().ReverseMap();
}
}
Thanks!
Scanning through the project, I noticed that somewhere in previous documentation - I read about creating a type of "config" class that just inherits from an abstract class called Profile. In this class you will also be able to define your maps, yet what is strange is that I am not able to drop this class and simply use the config maps setup in my Startup.cs file. Automapper will refuse to hold any maps that are not defined in this separate class. The below seems to get me what I need, however I still need an explanation as to why Automapper doesn't function as desired without it:
public class AMConfig : Profile
{
public AMConfig()
{
CreateMap<ManageUserModel, IndexViewModel>();
CreateMap<IndexViewModel, ManageUserModel>();
CreateMap<NotificationViewModel, NotificationModel>().ReverseMap();
CreateMap<List<NotificationViewModel>, List<NotificationModel>>().ReverseMap();
CreateMap<TaskViewModel, TaskModel>().ReverseMap();
}
}
I'm using entity framework and I figured out that it ain't able to serialize the output of
EDM Objects. For now I'm using Northwind Products-table. SO thereforth I'm forced to cast the Object to another and are using the .Cast but it doesn't work.
The only solution I have is to property by property do it manually in my code, but I'm thinking - there must be a better way!
For god's sake - it is 2013! And this Entity seems like a good idea in the beginning but it has so many gotchas and constraints that it actually hinders more than it helps, but anyway the EDMX diagrams are nice!
Anybody who has a better solution to casting the objects?
POCO
public class Product
{
public int ProductID { get; set; }
public string ProductName { get; set; }
//public Nullable<int> SupplierID { get; set; }
//public Nullable<int> CategoryID { get; set; }
public string QuantityPerUnit { get; set; }
public Nullable<decimal> UnitPrice { get; set; }
public Nullable<short> UnitsInStock { get; set; }
public Nullable<short> UnitsOnOrder { get; set; }
public Nullable<short> ReorderLevel { get; set; }
//public bool Discontinued { get; set; }
public Category Category { get; set; }
//public ICollection<Order_Detail> Order_Details { get; set; }
//public Supplier Supplier { get; set; }
}
View Model
public class ProductsViewModel
{
public List<POCO.Product> Products { get; set; }
public ProductsViewModel()
{
using (NorthwindEntities dNorthwindEntities = new NorthwindEntities())
{
this.Products = dNorthwindEntities.Products.Cast<POCO.Product>().ToList();
Web api controller:
public class ProductsController : ApiController
{
public List<Product> GetAllProducts()
{
var viewmodel = new ProductsViewModel();
return viewmodel.Products;
}
1.
You can use frameworks like AutoMapper to handle Entities to ViewModel / DTO mapping automatically.
2.
Using Entities in the View (even in their POCO form) is not recommended for couple of reasons:
Security: Sending entities back to the client/view may expose more data than you intended.
Serialization: Since your entities usually contain reference to another entities and those entities may contain a reference back to the (parent) entity, you have to configure your serializer to handle this situation otherwise you'll get Circular Dependency Exception.
Incompatibility: The structure of your entity may not be compatible with what your view/client needs to render itself. Sometimes your view just needs a simple string while the entity holds this data in a much complex way hence the view needs to 'extract' it and you end up with a view full of unnecessary entity-drill-down code.
I have problem with EF 5 and Lazy loading with cyclic references.
The below picture represents my model.
The main problem is between Model and ModelProperties classes, because Model contains IEnumerable navigation property and ModelProperty contains Model navigation property.
So this design cause the situation below
You can access fullsize image http://tinypic.com/r/2vskuxl/6
As you can imagine this cause very big problem, OutOfMemory exception.
Only solution that i could find is disabling lazy loading and using other methods. But lazy loading is very simplifying our work.
I hope there is a configuration or an attribute to help me loading only two levels of relations with lazy loading.
Is there any way to achieve this?
UPDATE:
Regarding the request from Julie Lerman, here is the visual model of EF.
I highlighted the main relation that cause problem.
Also you can access full-size at http://tinypic.com/r/30v15pg/6
UPDATE 2:
Here is the model definitions.
public class Model {
public int ModelID { get; set; }
public int BrandID {
get;
set;
}
public virtual Brand Brand { get; set; }
public string Logo { get; set; }
public string Name { get; set; }
public virtual ICollection<ModelProperty> ModelProperties {
get;
set;
}
}
public class ModelProperty {
public int ModelPropertyID {
get;
set;
}
public virtual int PropertyDefinitionID {
get;
set;
}
public virtual PropertyDefinition PropertyDefinition {
get;
set;
}
public virtual int ModelID {
get;
set;
}
public virtual Model Model {
get;
set;
}
public bool IsContainable {
get;
set;
}
public bool HasFilterDefinition {
get;
set;
}
public virtual ICollection<ModelPropertyValue> ModelPropertyValues {
get;
set;
}
public virtual ICollection<ModelPropertyMatchingFilter> ModelPropertyMatchingFilter {
get;
set;
}
}
Also there is an entity configuration for ModelProperty.
public class ModelPropertyEntityTypeConfiguration : EntityTypeConfiguration<ModelProperty> {
public ModelPropertyEntityTypeConfiguration() {
HasKey(p => p.ModelPropertyID);
HasRequired(p => p.PropertyDefinition).WithMany(s => s.ModelProperties).HasForeignKey(s => s.PropertyDefinitionID).WillCascadeOnDelete(false);
HasRequired(p => p.Model).WithMany(s => s.ModelProperties).HasForeignKey(s => s.ModelID).WillCascadeOnDelete(false);
HasMany(p => p.ModelPropertyValues).WithRequired(s => s.ModelProperty).HasForeignKey(s => s.ModelPropertyID).WillCascadeOnDelete(true);
HasMany(p => p.ModelPropertyMatchingFilter).WithRequired(s => s.ContainerModelProperty).HasForeignKey(s => s.ContainerModelPropertyID).WillCascadeOnDelete(false);
ToTable("dbo.ModelProperties");
}
}
UPDATE 3:
I am not sure but Automapper can cause this also. Because Entity Framework Profile tells thousands of Autommaper methods called while running.
UPDATE 4:
Here is the EFProf stacktrace:
You access bigger version http://tinypic.com/r/21cazv4/6
UPDATE 5
You can see sample project here: https://github.com/bahadirarslan/AutomapperCircularReference
In sample, you can see easily endless loops via Quick watch.
Thanks for the update. You're model looks fine. It definitely knows this is just a 1:* relationship. Ladislav (as usual) is correct. LL doesn't cause the problem...except in ONE place which is during serialization. Is there a chance that you have your code in a service? With regular lazy loading, only the property you explicitly mention will get lazy loaded. But during serialization, the serialization "mentions" every property so it just keeps loading and loading properties throughout the graph AND causes circular dependency issues. With services we have to turn lazy loading off (using context.configuration.lazyloadingenabled=false) before you return the data. So in the service method, you can eager load, or lazy load or explicitly load to get your graph but then disable lazy loading before you return the results.
you should disable lazy loading in order to bypass proxy objects or you should return what you need as a DTO. using DTO is preferred because of hiding details of your domain
I'm currently working on and ASP.NET MVC application in which I have a User entity like follows:
public class User
{
public virtual int Id { get; protected set; }
public virtual string Name { get; protected set; }
public virtual string Role { get; protected set; }
public virtual Location Location { get; protected set; }
}
Where location is just as straightforward:
public class Location
{
public virtual string Id { get; protected set; }
public virtual string Building { get; protected set; }
public virtual string City { get; protected set; }
public virtual string Region { get; protected set; }
}
My complication arises because I want to populate the User from Active Directory and not the database. Additionally, several classes persisted to the database reference a user as a property. I've got an ADUserRepository for retrieval, but I don't know how to integrate these Users into my object graph when the rest is managed by NHibernate.
Is there a way for NHibernate to persist just an id for a User without it being a foreign key to a Users table? Can I map it as a component to accomplish this? I've also looked at implementing IUserType to make the translation. That way it would map to a simple field and ADUserRepository could be put in the chain to resolve the stored Id. Or am I trying to hack something that's not really feasible? This is my first time around with NHibernate so I appreciate any insight or solutions you can give. Thanks.
Update
It appears my best solution on this will be to map the User with an IUserType and inject (preferably with StructureMap) a service for populating the object before its returned. Framed in that light there are a couple of questions here that deal with the topic mostly suggesting the need for a custom ByteCodeProvider. Will I still need to do this in order for IUserType to take a parameterized constructor or do the comments here: NHibernate.ByteCode.LinFu.dll For NHibernate 3.2 make a difference?
using a Usertype to convert user to id and back
public class SomeClass
{
public virtual string Id { get; protected set; }
public virtual User User { get; protected set; }
}
// in FluentMapping (you have to translate if you want to use mapping by code)
public SomeClassMap()
{
Map(x => x.User).Column("user_id").CustomType<UserType>();
}
public class UserType : IUserType
{
void NullSafeSet(...)
{
NHibernateUtil.Int32.NullSafeSet(cmd, ((User)value).Id, index);
}
void NullSafeGet(...)
{
int id = (int)NHibernateUtil.Int32.NullSafeGet(cmd, ((User)value).Id, index);
var userrepository = GetItFromSomeWhere();
return userrepository.FindById(id);
}
}
I'm having some trouble figuring out the appropriate FluentNHibernate mapping syntax for the following data model and domain objects. Here's the data model I'm working against:
And I'm trying to map the following domain objects to that model:
namespace FluentNHibernateSandbox.Entities
{
public abstract class EntityBase
{
public virtual long Id { get; set; }
}
}
namespace FluentNHibernateSandbox.Entities
{
public class Attribute : EntityBase
{
public virtual string Name { get; set; }
public virtual string Label { get; set; }
public virtual string Description { get; set; }
public virtual int SortOrder { get; set; }
public virtual Group Group { get; set; }
public virtual Editor Editor { get; set; }
}
}
namespace FluentNHibernateSandbox.Entities
{
public class Group : EntityBase
{
public virtual string Name { get; set; }
public virtual string Label { get; set; }
public virtual string Description { get; set; }
public virtual int SortOrder { get; set; }
public virtual IList<Attribute> Attributes { get; set; }
}
}
namespace FluentNHibernateSandbox.Entities
{
public class Editor : EntityBase
{
public virtual string ViewName { get; set; }
public virtual string WorkerClassName { get; set; }
}
}
In general, what I ultimately want doesn't seem like it should be all that hard to do, but I after having tried just about every combination of mappings I can think of, I still can't seem to get it right. I just need my Attribute to have a reference to the Group that it belongs to and a reference to the Editor assigned to it, and each Group should have a collection of the Attributes that are part of it. The couple of many-to-many join tables are what seem to be giving me fits. Particularly the APPLICATION_ATTRIBUTE table. Ultimately I only want the Attributes that my application is concerned with, in this case, those with an APPLICATION_ID of 4.
Any help would be greatly appreciated. Thanks.
Really kinda surprised nobody responded to this at all, but anyway. The answer/solution for this mapping situation that we came up with, which I was trying to avoid to start with, but turned out to really be the best way to go, was to create some custom views in the database that joined together all of the application-specific data I needed, and then just mapped my application's domain objects to those views. This worked at least partially because the information I needed from these tables is going to be read-only for this application, but even if I needed to write to the tables, I'm pretty sure (though haven't verified as I didn't really have need in this case) that I could have setup my views to be writeable and that would've worked too.
Hat tip to #robconery.