I need to create a generic way to add missing languages entries to all entities in which implements an specific interface. I found out how to get my collection property, but I still don't know how to add new values on it before proceed to save.
Following a piece of my public override int SaveChanges() handling.
foreach (var translationEntity in ChangeTracker.Entries(<ITranslation>))
{
if (translationEntity.State == EntityState.Added)
{
var translationEntries = translationEntity.Entity.GetType()
.GetProperties(BindingFlags.Public | BindingFlags.Instance)
.Where(x => x.CanWrite &&
x.GetGetMethod().IsVirtual &&
x.PropertyType.IsGenericType == true &&
typeof(IEnumerable<ILanguage>).IsAssignableFrom(x.PropertyType) == true);
foreach (var translationEntry in translationEntries)
{
//Add missing items.
}
}
}
Classes code samples
public partial class FileType : ITranslation
{
public long FileTypeId { get; set; }
public string AcceptType { get; set; }
public virtual ICollection<FileTypeTranslation> FileTypeTranslations { get; set; }
public FileType()
{
this.FileTypeTranslations = new HashSet<FileTypeTranslation>();
}
}
public class FileTypeTranslation : EntityTranslation<long, FileType>, ILanguage
{
[Required]
public string TypeName { get; set; }
}
public partial class ElementType : ITranslation
{
public long ElementTypeId { get; set; }
public string Code { get; set; }
public virtual ICollection<ElementTypeTranslation> ElementTypeTranslations { get; set; }
public ElementType()
{
this.ElementTypeTranslations = new HashSet<FileTypeTranslation>();
}
}
public class ElementTypeTranslation : EntityTranslation<long, ElementType>, ILanguage
{
[Required]
public string Description { get; set; }
}
Entries from ChangeTracker have property called Entity which holds original entity
foreach (var fileType in ChangeTracker.Entries(<FileType>))
{
fileType.Entity.FileTypeTranslations.Add();
}
and for ElementType:
foreach (var elementType in ChangeTracker.Entries(<ElementType>))
{
elementType.Entity.ElementTypeTranslations.Add();
}
I didn't test, but it was too long to paste in comment.
Related
I am trying to create a view to display product information and its related images. I am using repository pattern,
please see the code below, I will really appreciate your help
public class ProductDetail
{
public int pro_id { get; set; }
public string pro_name { get; set; }
public string pro_model { get; set; }
public string pro_Dimensions { get; set; }
public string pro_imageTitle { get; set; }
public string pro_image { get; set; }
public string pro_desc { get; set; }
public Nullable<double> pro_price { get; set; }
public int pro_UnitsInStock { get; set; }
public Nullable<double> pro_oldprice { get; set; }
public virtual ICollection<Images> tbl_Images { get; set; }
}
public class Images
{
public int ImageID { get; set; }
public int productID { get; set; }
public string ImageTitle { get; set; }
public string ImagePath { get; set; }
}
public class ProductDetailRepository : IProductDetail
{
private readonly WebStoreEntities storeDB;
public ProductDetailRepository() { }
public ProductDetailRepository(WebStoreEntities _storeDB)
{
this.storeDB = _storeDB;
}
public ProductDetail GetProductByID(int id)
{
var prod = storeDB.tbl_Product
.Where(x => x.pro_id == id)
.Include(p => p.tbl_Images)
.FirstOrDefault();
return prod; (Here it says, cannot implicitly convert type tbl_product to productdetail (this is where i need help))
}
tbl_product is from the EDMX model.
}
now, i am stcuk in this method, all i want is to return the product info and related images to the controller and then view.
You basically just need to convert your tbl_Product that you get from the database into the ProductDetail you want to return:
public ProductDetail GetProductByID(int id)
{
var prod = storeDB.tbl_Product
.Where(x => x.pro_id == id)
.Include(p => p.tbl_Images)
.FirstOrDefault();
if (prod == null)
{
return null;
}
ProductDetail result = new ProductDetail
{
// I'm just *GUESSING* here since you haven't showed
// the tbl_product class, so I don't know what the
// properties on that class are called, really...
pro_id = prod.Id,
pro_name = prod.Name
// and so on for all the properties
}
return result;
}
I get this error (An exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll but was not handled in user code
The entity type tblMessage is not part of the model for the current context.) and have tried fixes I found online but they didnt seem to help. I also did somethin similar for another database tabel earlier in the code.
Im trying to retrieve messages form my database table called tblMessages.
Constructor:
public JsonResult ConversationWithContact(int contact)
{
if (Session["UserID"] == null)
{
return Json(new {status = "error", message = "User is not logged in"});
}
//var currentUser = (Models.tblUser)Session["UserID"];
var conversations = new List<Models.tblMessage>();
using (var db = new Models.ChatContext())
{
int currentUserId = (int)Session["UserID"];
var currentUser = db.Users.FirstOrDefault(x => x.Id == currentUserId);
conversations = db.Conversations.Where(c => (c.receiverId == currentUser.Id
&& c.senderId == contact) ||
(c.receiverId == contact
&& c.senderId == currentUser.Id))
.OrderBy(c => c.created_at)
.ToList();
}
return Json(
new {status = "success", data = conversations},
JsonRequestBehavior.AllowGet
);
}
Context:
public ChatContext() : base("TrinityEntities")
{
}
public static ChatContext Create()
{
return new ChatContext();
}
public DbSet<tblUser> Users { get; set; }
public DbSet<tblMessage> Conversations { get; set; }
Database model class:
public class tblMessage
{
public tblMessage()
{
status = messageStatus.Sent;
}
public enum messageStatus
{
Sent,
Delivered
}
public int Id { get; set; }
public int senderId { get; set; }
public int receiverId { get; set; }
public string message { get; set; }
public messageStatus status { get; set; }
public System.DateTime created_at { get; set; }
}
Here is issue with Table Mapping to database. each entity will be set up to map to a table with the same name as the DbSet<TEntity> property that exposes to the derived context. If no DbSet<TEntity> is included for the given entity, the class name is used.
as you set in your code Users and Conversations is not table name. for that you can customize also refere https://learn.microsoft.com/en-us/ef/core/modeling/relational/tables
and use Data Annotations for specify table name.
public messageStatus status { get; set; }
i think this property is not not part of your table column so you have to specify [NotMapped] Data Annotations.
after changes and adding Data Annotations to table context and table look likes.
public class ChatContext : DbContext
{
public ChatContext()
{
}
public virtual DbSet<tblUser> Users { get; set; }
public virtual DbSet<tblMessage> Conversations { get; set; }
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
if (!optionsBuilder.IsConfigured)
{
optionsBuilder.UseSqlServer("Server=(localdb)\\mssqllocaldb;Database=test;Trusted_Connection=True;MultipleActiveResultSets=true");
}
}
}
and your models(tables) entities look like.
[Table("tblMessage")]
public class tblMessage
{
public tblMessage()
{
status = messageStatus.Sent;
}
public enum messageStatus
{
Sent,
Delivered
}
public int Id { get; set; }
public int senderId { get; set; }
public int receiverId { get; set; }
public string message { get; set; }
[NotMapped]
public messageStatus status { get; set; }
public System.DateTime created_at { get; set; }
}
[Table("tblUser")]
public class tblUser
{
public int id { get; set; }
public string name { get; set; }
}
now you can access your Conversations and Users after adding [Table("<table-name>")] Data-Annotations.
also you can use Fluent API for table mapping.
after using table mapping table after debug code image like.
i hope it helps you and let me know if require any more information. :)
I have data in model and I used to store that data in session as below in controller
if (providerListingModel.ServiceDetails != null && providerListingModel.ServiceDetails.Count > 0)
Session["ServiceDetails"] = providerListingModel.ServiceDetails;
else
Session["ServiceDetails"] = null;
and for retrieving I had used the logic as
if (Session["ServiceDetails"] != null)
{
if (providerListingModel.ServiceDetails == null)
{
List<ServiceDetail> sam = (List<ServiceDetail>)Session["ServiceDetails"];
foreach (var items in sam)
{
var sd = new ServiceDetail();
sd.Id = items.Id;
sd.CategoryServiceId = items.CategoryServiceId;
sd.ServiceType = items.ServiceType;
sd.ServicePrice = items.ServicePrice;
sd.IsSelected = items.IsSelected;
sd.ProviderListingId = providerListingModel.ProviderListingId;
providerListingModel.ServiceDetails.Add(sd);
}
}
Session["ServiceDetails"] = null;
}
The session contains data but on providerListingModel.ServiceDetails.Add(sd); it throw null exception.
ServiceDetails is a class and it contains list of items
namespace xyz.DAL
{
using System;
using System.Collections.Generic;
public partial class ServiceDetail
{
public int Id { get; set; }
public int ProviderListingId { get; set; }
public Nullable<int> CategoryServiceId { get; set; }
public string ServiceType { get; set; }
public Nullable<int> ServicePrice { get; set; }
public string CustomeService { get; set; }
public Nullable<bool> IsSelected { get; set; }
public virtual CategoryService CategoryService { get; set; }
public virtual ProviderListing ProviderListing { get; set; }
}
}
am I missing some code?
As I am new I don't know what I am doing wrong
You are inserting the item to null value, so it throws an error. Create new instance of the list and add an item to collection.
if(providerListingModel.ServiceDetails ==null)
providerListingModel.ServiceDetails = new List<ServiceDetail>();
i have 3 model:
1st one:
public class CreateFieldModel
{
public FieldModel fm { get; set; }
public CategoryModel cm { get; set; }
}
2nd one:
public class FieldModel
{
public string field_Name { get; set; }
public InputTypeModel itm { get; set; }
public string input1 { get; set; }
public string input2 { get; set; }
public string input3 { get; set; }
public string input4 { get; set; }
public List<InputTypeModel> inputs { get; set; }
}
3rd One:
public class InputTypeModel
{
public string inputTypeName { get; set; }
public string inputTypeDesc { get; set; }
}
2 methods:
1st One:
public List<InputTypeModel> getInputTypes()
{
var inptypes = edu.InputTypes;
List<InputTypeModel> listInputTypes = new List<InputTypeModel>();
foreach (var inpType in inptypes)
{
listInputTypes.Add(new InputTypeModel { inputTypeName = inpType.Input_Type_Name, inputTypeDesc = inpType.Input_Type_Description });
}
return listInputTypes;
}
when this method executes listInputTypes has three different values.. i check it by debugging.. so no roblem here. This methos is under the class FormManagement.. I am calling this method from the following action method:
[HttpGet]
public ActionResult createNewField(CreateFieldModel cfm, string fcode)
{
FormManagement ffm = new FormManagement();
cfm.fm.inputs = ffm.getInputTypes();
return View(cfm);
}
when cfm.fm.inputs = ffm.getInputTypes(); executes it is showing "Object reference not set to an instance of an object." message... I am quite beginner to mvc.. please help
Without knowing what you really want to achieve with cfm-parameter in your action, the only thing I can suggest is to check for null references and create new instances before you assign them:
[HttpGet]
public ActionResult createNewField(CreateFieldModel cfm, string fcode)
{
FormManagement ffm = new FormManagement();
if (cfm == null)
{
cfm = new CreateFieldModel();
}
if (cfm.fm == null)
{
cfm.fm = new FieldModel();
}
cfm.fm.inputs = ffm.getInputTypes();
return View(cfm);
}
Of course, this supposes that your not relying on incoming data through your route parameters. If you are, you need to check why the values are not getting passed in, but I'm guessing you don't need it as a parameter in the first place.
Im having trouble linking my loaned items to my Library for each customer. It does it fine when it goes through the "AddToLibrary" method but when it comes to retreiving it, the medialibrary is empty and the query in the IEnumerable<Item> ItemsOnLoan method is returning null. This is a very basic ASP.NET MVC 4 application and im very new to this so its probably something silly ive missed out.
I just want to be able to add an item to the loaned items table, have the list of loaned items for each customer appear in their personal Library (defined in model) and then retreive the list of their items. Below is all the code and I am using a code first approach. Thank you :)
Model
public class Customer
{
public int Id { get; set; }
public string ForeName { get; set; }
public string SurName { get; set; }
public Address address { get; set; }
public string Email { get; set; }
public string Telephone { get; set; }
public string Mobile { get; set; }
public List<LoanedItem> Library { get; set; }
public Customer()
{
if (Library == null || Library.Count == 0)
{
Library = new List<LoanedItem>();
}
}
public IEnumerable<Item> ItemsOnLoan
{
get
{
var items = (from i in Library
where i.Customer.Id == this.Id
select i).OfType<item>();
return items;
}
}
}
Loaned Item model
public class LoanedItem
{
public int? Id { get; set; }
public Customer Customer { get; set; }
public MediaItem Item { get; set; }
}
ItemController --> adding to library method
public ActionResult AddToLibrary(int id)
{
Item libraryItem = db.Items.Find(id);
Customer c = db.Customers.Find(1);
LoanedItem newLoanGame = new LoanedItem()
{
Customer = c,
Item = libraryItem
};
db.LoanedItems.Add(newLoanGame);
db.SaveChanges();
return RedirectToAction("Index");
}
Customer Controller
public ActionResult ViewProfile(int id = 1)
{
Customer c = db.Customers.Find(id);
if (c == null)
{
return HttpNotFound();
}
return View(c);
}
public ActionResult GetLibraryItems(int id = 1)
{
var items = db.Customers.Find(id).ItemsOnLoan;
return View(items);
}
Context
public class LibraryContext : DbContext
{
public DbSet<Address> Addresses { get; set; }
public DbSet<Customer> Customers { get; set; }
public DbSet<LoanedItem> LoanedItems { get; set; }
public DbSet<Item> Items { get; set; }
public LibraryContext()
: base("LbContext")
{
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new CustomerConfiguration());
modelBuilder.Configurations.Add(new LoanedItemConfiguration());
modelBuilder.Entity<Item>();
modelBuilder.Entity<Address>();
base.OnModelCreating(modelBuilder);
}
}
Assuming that Proxy generation is enabled try this:
public class Customer
{
public int Id { get; set; }
public string ForeName { get; set; }
public string SurName { get; set; }
public Address address { get; set; }
public string Email { get; set; }
public string Telephone { get; set; }
public string Mobile { get; set; }
public virtual ICollection<LoanedItem> ItemsOnLoan { get; set; }
public Customer()
{
}
}
using this to acccess:
public ActionResult GetLibraryItems(int id = 1)
{
var customer = db.Customers.Find(id);
if (customer != null)
{
var items = customer.ItemsOnLoan;
return View(items);
}
//handle not found or throw an exception
throw new Exception();
}
follow this link for more information on Proxies and Lazy Loading.