I got this DomainService method I'm calling from my SL ViewModel using the Invoke attribute:
[Invoke]
public ServiceModel.Recipy GetRecipyById(int recipyId)
{
return new Recipy
{
RecipyId = 1,
Name = "test",
Description = "desc",
Author = new Author
{
AuthorId = 1,
Name = "Johan"
}
};
}
The code in my ViewModel looks like this:
public RecipyViewModel()
{
context.GetRecipyById(1, RecipyLoadedCallback, null);
}
private void RecipyLoadedCallback(InvokeOperation<Recipy> obj)
{
_name = obj.Value.Name;
_description = obj.Value.Description;
_authorName = obj.Value.Author.Name;
}
The Recipy and Author POCO/ServiceModel classes:
public class Recipy
{
[Key]
public int RecipyId { get; set; }
public string Name { get; set; }
public string Description { get; set; }
[Association("Author", "RecipyId", "AuthorId")]
[Include]
public Author Author { get; set; }
}
public class Author
{
[Key]
public int AuthorId { get; set; }
public string Name { get; set; }
}
Now, the code works fine, except that the associated Author is not transfered over to the client/viewmodel, the Author property of Recipy is null. I thought that using the [Associate] and [Include] attributes would do the trick?
Thanks for any help, I'm trying hard to grok the DomainService/RIA stuff and I'm close to giving up and go "normal" WCF/REST instead :)
As I understand it, [Invoke] doesn't support complex hierarchies at the moment, so I solved it by making sure I had the correct attributes for [Include] and [Association] on the collection, and went back to using a normal RIA query method instead.
Related
Let's take an example model:
public class Person
{
public string Name {get; set;}
public List<Guitar> Guitars {get; set;}
}
public class Guitar
{
public string Brand {get; set;}
public string Model {get; set;}
}
I need to create a View with a list of all People and a count of how many guitars they have. To do that I would like to pass a ViewModel like this one populated with EF without loading all Guitards:
// This will be send to the View, I can also just send a List
public class ViewModelPassed
{
List<PeopleGuitarViewModel> AllPeople { get; set; }
}
// This should be populated from EF
public class PeopleGuitarViewModel
{
public string Name { get; set; }
public int NumberOfGuitars { get; set; }
}
Can I query EF to a different class, and avoid bringing the whole list of guitars and instead get a COUNT in SQL?
Thanks!
You should provide primary key to your models for EF core to create the relationship:
public class Person
{
public int ID { get; set; }
public string Name { get; set; }
public List<Guitar> Guitars { get; set; }
}
public class Guitar
{
public int ID { get; set; }
public string Brand { get; set; }
public string Model { get; set; }
}
Also use public for AllPeople property in ViewModelPassed:
public List<PeopleGuitarViewModel> AllPeople { get; set; }
Then query like :
ViewModelPassed modelPassed = new ViewModelPassed();
modelPassed.AllPeople = new List<PeopleGuitarViewModel>();
modelPassed.AllPeople = _applicationDbContext.Persons.Select(x =>
new PeopleGuitarViewModel
{
Name = x.Name,
NumberOfGuitars = x.Guitars.Count
}).ToList();
One way is to do it like this:
var viewModel=context.Persons.Select(x=>new PeopleGuitarViewModel
{
Name=x.Name,
NumberOfGuitars=Guitars.Count()
}).ToList();
this kind of query is also named Projection and is consider best practice (do not send full entity to the view).
There are 2 libraries which I often use for such projections: AutoMapper and/or Mapster.
Hope this help you.
When populating your ViewModel, you can use Linq to get the count. Like this:
PeopleGuitarViewModel p= new PeopleGuitarViewModel();
p.Name = person.Name;
p.NumberOfGuitars = person.Guitars.Count;
Where person is an object of your Person class.
I use Asp.Net MVC, Entity Framework. I have a form it looks like below.
Here, dropdownlist is filled from a table(types). Checkboxes is filled from another table(test). Tables are like below:
public class Types
{
public int TypesID{get;set;}
public string TestName { get; set; }
public string TestExplanation { get; set; }
public int TestTime { get; set; }
}
public class Tests
{
public int TestID{get;set;
public string Name { get; set; }
public string Code { get; set; }
}
public class Types_Tests
{
public int Types_TestsID{ get; set; }
public int TypesID { get; set; }
public int TestsID { get; set; }
public virtual Types Types { get; set; }
public virtual Tests Tests { get; set; }
}
Types_test table is relation table between Types and Tests. When I click Kaydet button, it shuld save type and checked tests. I made this operation using ViewBag, javascript and hdnvalue.I added checked checkboz values to a hdntext. I made saving process like below:
[HttpPost]
public ActionResult Index(string drpType, string hdntesttypes)
{
var TypeList = Types.GetAll();
ViewBag.TypesList = new SelectList(TypeList, "Id", "Name");
var testypeList = testTypes.GetAll();
ViewBag.TestTypesList = new SelectList(testypeList, "Id", "TestName");
GenericRepository<TestDisabledTypes> testDisabledRepository = new GenericRepository<TestDisabledTypes>(_context);
if (!string.IsNullOrEmpty(hdntesttypes))
{
string[] disabletypesArray = hdntesttypes.Split(',');
using (TransactionScope trns = new TransactionScope())
{
for (int i = 0; i < disabletypesArray.Length; i++)
{
Test_Types types = new Test_Types ();
types.TestTypesID = Convert.ToInt32(disabletypesArray[i]);
types.TypesID = Convert.ToInt32(drpType);
testDisabledRepository.Insert(types);
}
trns.Complete();
}
}
return View();
}
It wokrs. But I search better solution for this process. Can someone give me any idea?
Thanks.
If you don't need additional attributes for your entity class, you don't need create link table.
Just define the following class, and EF will generate the link table for you automatically.
public class Type
{
public int TypesID{get;set;}
public string TestName { get; set; }
public string TestExplanation { get; set; }
public int TestTime { get; set; }
public ICollection<Test> Tests { get; set; }
}
public class Test
{
public int TestID{get;set;
public string Name { get; set; }
public string Code { get; set; }
public ICollection<Type> Types {get;set;}
}
Well, in EntityFramework if you want to create a many to many relation object you need to create new object of "linking" entity. Unfortunately, it is not possible to add first object, add second object and say "Guys, you are in many to many relationships. Are you happy then?" :) You need to create relation object, set appropriate fields in it (I think these are ids of two objects itself) and add it to relation collection (entity) in your model. But before doing so you need to be sure that objects with data you are linking with are already exists in database. Otherwise you'll get an error
Also it's not necessary to create manually transaction because EF does it for you automatically each time you get/save your data
how do I insert data in many to many relationship?
I have these two models definded by this code
public class Article
{
public int ArticleID { get; set; }
public string Title { get; set; }
public DateTime Date { get; set; }
public string Anotation { get; set; }
public string Body { get; set; }
public virtual ICollection<ArticleTag> ArticleTags { get; set; }
}
public class ArticleTag
{
public int ArticleTagID { get; set; }
public string TagName { get; set; }
public virtual ICollection<Article> Articles { get; set; }
}
Now the big Q is how to seed the database with test data. I have some experience with normal tables and queries and in MVC EF I am quite a novice. Normally I would create an association table and in it define the link between these models. But I have read many tutorials and none gave me a deterministic way how to do it, so I you can imagine my confusion.
As I said before, I "created" an assoc table via ModelBuilder and that's where I end :(
public class DatabaseContext : DbContext
{
public DbSet<Article> Articles { get; set; }
public DbSet<ArticleTag> ArticleTags { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Article>().
HasMany(at => at.ArticleTags).WithMany(a => a.Articles).
Map(m => m.MapLeftKey("ArticleID").MapRightKey("ArticleTagID").ToTable("Articles_To_ArticleTags"));
}
}
I need to know the easiest way to seed my DB (don't care if have to delete the assoc table) and understand how it works in the MVC - linking the two models, linking two specific instances, ... , and how to code it all.
Thx for any answer.
So finally solved!
Found a good post here and with this one together I made it work.
In short what I had to do:
Remove my builder link - EF itself creates link (own assoc table)
A little modify models
Create DatabaseInitializer
In the Global.asax to the method Application_Start() add Database.SetInitializer(new DatabaseInitializer()); declaration
don't forget to se ConnectionString and DBcontext
Normally use in a View
Modifications in constructor (not sure if absolutely necessary, maybe it does the same thing as native/default constructor):
public class Article
{
public int ArticleID { get; set; }
public string Title { get; set; }
public DateTime Date { get; set; }
public string Anotation { get; set; }
public string Body { get; set; }
public string SourceLink { get; set; }
public virtual List<ArticleTag> ArticleTags { get; set; }
public Article()
{
ArticleTags = new List<ArticleTag>();
}
}
public class ArticleTag
{
public int ArticleTagID { get; set; }
public string TagName { get; set; }
public virtual List<Article> Articles { get; set; }
public ArticleTag()
{
Articles = new List<Article>();
}
}
And the DatabaseInitializer
public class DatabaseInitializer : DropCreateDatabaseIfModelChanges<DatabaseContext>
{
protected override void Seed(DatabaseContext context)
{
ArticleTag tag1= new ArticleTag { TagName = "aaaa" };
ArticleTag tag2= new ArticleTag { TagName = "bbbb" };
ArticleTag tag3= new ArticleTag { TagName = "cccc" };
var articleTags = new List<ArticleTag> { tag1, tag2, tag3};
articleTags.ForEach(i => context.ArticleTags.Add(i));
context.SaveChanges();
Article a1 = new Article
{
Title = "Title1",
Date = DateTime.Now,
Anotation = "Anotation1",
Body = "article_1",
ArticleTags = new List<ArticleTag> { tag1 }
};
Article a2 = new Article
{
Title = "Title12",
Date = DateTime.Now,
Anotation = "Anotation2",
Body = "article_2",
ArticleTags = new List<ArticleTag> { tag2, tag3 }
};
var articles = new List<Article> { a1, a2 };
articles.ForEach(a => context.Articles.Add(a));
context.SaveChanges();
}
}
I'm working on my first MVC 4 app, following the MVC First Web API Tutorial on Asp.net. I've left the names the same, but changed the model and controller code. Here's my model:
public class Product
{
public string SID { get; set; }
public string name { get; set; }
public string givenName { get; set; }
public string sn { get; set; }
public string mail { get; set; }
public string telephoneNumber { get; set; }
public string mobile { get; set; }
public string otherMobile { get; set; }
public string title { get; set; }
public string Manager { get; set; }
public DateTime whenChanged { get; set; }
}
public class ProductModel
{
public ProductModel()
{
ProductList = new List<Product>();
}
public IList<Product> ProductList { get; set; }
}
And here's my APIcontroller:
public class ProductsController : ApiController
{
ProductModel products = new ProductModel();
public IEnumerable<Product> GetAD()
{
DirectoryEntry domainRoot = new DirectoryEntry(LDAP_server);
DirectorySearcher searcher = new DirectorySearcher(searchStr);
SearchResultCollection results = searcher.FindAll();
foreach (SearchResult srchResult in results)
{
DirectoryEntry dirEntry = srchResult.GetDirectoryEntry();
if (dirEntry.Properties["givenName"].Value != null && dirEntry.Properties["sn"].Value != null && !dirEntry.Parent.Name.Contains("Terminated"))
{
products.ProductList.Add(new Product()
{
SID = dirEntry.Properties["sid"].Value.ToString(),
name = dirEntry.Properties["name"].Value.ToString(),
givenName = dirEntry.Properties["givenName"].Value.ToString(),
sn = dirEntry.Properties["sn"].Value.ToString(),
mail = dirEntry.Properties["mail"].Value.ToString(),
telephoneNumber = dirEntry.Properties["telephoneNumber"].Value.ToString(),
mobile = dirEntry.Properties["mobile"].Value.ToString(),
otherMobile = dirEntry.Properties["otherMobile"].Value.ToString(),
title = dirEntry.Properties["title"].Value.ToString(),
Manager = dirEntry.Properties["Manager"].Value.ToString(),
whenChanged = Convert.ToDateTime(dirEntry.Properties["whenChanged"].Value.ToString()),
});
}
}
return products.ProductList;
}
}
I'm getting the NullException on 'products.ProductList.Add(new Product()', am I missing something simple? Please forgive my coding, as I'm just trying to get this up and running, thanks.
the problem mostly likely is dealing with dirEntry, not Web API itself. rather than introduce LDAP into this, just create a bunch of dummy products to return.
FYI... there is also a memory leak issue with the use of LDAP objects. They need to be properly disposed of, both along the happy path and if an exception is thrown.
I'm an idiot. 'sid' is not the correct property name from AD, it is 'objectSid', thus always returning a null. I knew it was something simple.
I am trying to figure out how to generically map a domain model to a presentation model. For example, given the following simple objects and interfaces ...
// Product
public class Product : IProduct
{
public int ProductID { get; set; }
public string ProductName { get; set; }
}
public interface IProduct
{
int ProductID { get; set; }
string ProductName { get; set; }
}
// ProductPresentationModel
public class ProductPresentationModel : IProductPresentationModel
{
public int ProductID { get; set; }
public string ProductName { get; set; }
public bool DisplayOrHide { get; set; }
}
public interface IProductPresentationModel
{
int ProductID { get; set; }
string ProductName { get; set; }
bool DisplayOrHide { get; set; }
}
I would like to be able to write code like this ...
MapperObject mapper = new MapperObject();
ProductService service = new ProductService();
ProductPresentationModel model = mapper.Map(service.GetProductByID(productID));
... in which the "MapperObject" could automatically figure out which properties map across the two objects and what sort of objects it is mapping using something like reflection, convention-based mapping, etc. So, I could then just as easily try to map objects like UserPresentationModel and User with the same MapperObject.
Is this possible? If so, how?
EDIT: Just for clarity, here is an example of a non-generic MapperObject that I am currently using:
public class ProductMapper
{
public ProductPresentationModel Map(Product product)
{
var presentationModel = new ProductPresentationModel(new ProductModel())
{
ProductID = product.ProductID,
ProductName = product.ProductName,
ProductDescription = product.ProductDescription,
PricePerMonth = product.PricePerMonth,
ProductCategory = product.ProductCategory,
ProductImagePath = product.ProductImagePath,
ProductActive = product.ProductActive
};
return presentationModel;
}
}
I am still trying to work out how to get this to work with List, instead of just a single Product, but that's a different topic :)
I see want you want. You want to map your domain entities (Product) to aome kind of DTO object (ProductPresentationModel) for communication with your clients (GUI, external services etc).
I you have all this functionality you're looking for packed into AutoMapper framework.
You can write like this with AutoMapper:
Mapper.CreateMap();
look at this wiki https://github.com/AutoMapper/AutoMapper/wiki/Flattening
Good luck.
/Best Regards Magnus