I have a model
public class Product : BaseEntity
{
private string _name;
public string Name
{
get { return _name; }
private set{_name = value;}
}
public decimal Price { get; set; }
public double Weight { get; set; }
public double Width { get; set; }
public double Height { get; set; }
public double Depth { get; set; }
public DateTime DateAdded { get; set; }
...
public string GeneralInfo {get{//some get logic}...}
}
and a View model:
public sealed class ProductDetailsModel
{
public int Id { get; set; }
public string Name { get; set; }
public decimal Price { get; set; }
public double Weight { get; set; }
public double Width { get; set; }
public double Height { get; set; }
public double Depth { get; set; }
...
public string GeneralInfo {get;set;}
}
and controller:
public class ProductController : Controller
{
...
public ActionResult Details(int id)
{
var product = _productRepository.GetProduct(id);
var productViewModel = Mapper.Map<ProductDetailsModel>(product);
return View(productViewModel);
}
...
}
everything works great, BUT... I have some get logic for product model general info property, which gets this general info from database, and sometimes, when product doesn't have general info, this property returns null. What I need is to generate alternative general info from available properties such as With, Height, etc. Something like:
private string GenerateGeneralInfoFromProductProperties()
{
var generalInfoStringBuilder = new StringBuilder();
generalInfoStringBuilder.Append(#"<b>Width: </b>").Append(Width).Append("</br>");
generalInfoStringBuilder.Append(#"<b>Weight: </b>").Append(Weight).Append("</br>");
...
return generalInfoStringBuilder.ToString();
}
If I add this logic to product model ...
public class Product : BaseEntity
{
...
public string GeneralInfo
{
get
{
var gInfo = getGeneralInfoFromBD();
if (gInfo==null)
gInfo = GenerateGeneralInfoFromProductProperties();
return gInfo;
}
set { SetPropertyValue(ProductPropertyType.GeneralInfo, value); }
}
}
Everything works fine, BUT it would be wrong and illogical, because I have a view model for representation of product details, so I want to add this logic to view model, but my view model instance is created by mapper, Product view model has no constructors to pass product instance to get it's general info, because, as I said, it has no need in constructor. How can I add this "general info if null" replace logic to mapper, or view model?
Try AfterMap
Automapper.CreateMap<Product,ProductDetailsModel>()
.AfterMap((p,pm) => {
// now you have access to both objects, so you can do whatever you please
});
Related
I have two tables in my database that have similar data but not same.
I'd like to show these tables in the same view. Looking in internet the most suggested practice is to use a ViewModel class.
So... These are my class tables:
iCareIndoorAlert.cs
[Table("iCareIndoorAlerts")]
public class iCareIndoorAlert
{
[Key]
[DisplayName("ID Allarme iCare indoor")]
public long AlertID { get; set; }
[DisplayName("ID Messaggio")]
public long MessageID { get; set; }
public string UUID { get; set; }
public int MAG { get; set; }
public int MIN { get; set; }
[DisplayName("Distanza")]
public float Dist { get; set; }
[DisplayName("Data ora")]
public DateTime DateTime { get; set; }
public virtual HttpPop3 HttpPop3 { get; set; }
}
iCareOutdoorAlert.cs
[Table("iCareOutdoorAlerts")]
public class iCareOutdoorAlert
{
[Key]
[DisplayName("ID Allarme iCare outdoor")]
public long AlertID { get; set; }
[DisplayName("ID Messaggio")]
public long MessageID { get; set; }
[DisplayName("Latitudine")]
public float Lat { get; set; }
[DisplayName("Longitudine")]
public float Lon { get; set; }
[DisplayName("Accuracy")]
public float Acc { get; set; }
[DisplayName("Data ora")]
public DateTime DateTime { get; set; }
}
After I created a ViewModel folder with a iCareAlertViewModel.cs class:
public List<iCareIndoorAlert> iCareIndoorAlert { get; set; }
public List<iCareOutdoorAlert> iCareOutdoorAlert { get; set; }
And added there rows in the iCareEntities.cs:
public DbSet<iCareIndoorAlert> iCareIndoorAlerts { get; set; }
public DbSet<iCareOutdoorAlert> iCareOutdoorAlerts { get; set; }
public DbSet<iCareAlertViewModel> iCareAlertsViewModels { get; set; }
After I generated the iCareAlertController.cs and run the view Index.cshtml but I get the error "Key not found". So in the ViewModel I added a dummy variable with [Key] attribute and now a get an error that says that can't find the iCareAlertViewModel table...
What am I doing wrong?
Thank you
First, don't create a DbSet for your view model, that's not necessary. A view model is a POCO that sits between your data models (i.e. your entities) and your user interface.
What you probably need to do is define an interface that has the properties that are common to your two entities, so something like this:
public interface IAlert
{
long AlertID { get; set; }
long MessageID { get; set; }
//etc...
}
Now each entity can implement that interface:
public class iCareIndoorAlert : IAlert
{
//snip
}
Now your viewmodel:
public class AlertViewModel : IAlert
{
public long AlertID { get; set; }
public long MessageID { get; set; }
//snip
}
So your view will now be something like this:
#model IEnumerable<My.Assembly.AlertViewModel>
#foreach(var alert in Model)
{
#Html.DisplayFor(m => m.AlertID)
//etc
}
Finally you need something to map your entities to your view model, you can use a library like Automapper but manually, it's something like this (including the action method and return):
public ActionResult Index()
{
List<IAlert> alerts = GetOutdoorAlerts(); //for example
List<AlertViewModel> alertViewModels = alert
.Select(a => new AlertViewModel
{
AlertID = a.AlertID,
MessageID = a.MessageID,
//etc...
});
return View(alertViewModels);
}
I'm trying to sort out this issue but as I'm learning a lot of this stuff as I go along I'd really appreciate it if someone could explain where I'm going wrong and/or some good resources where I can read up.
So, I have a model based on my Entity Framework model of my database and a viewmodel representing properties in that model. I've built a Kendo grid to display the data (defined in a js file) and the method in the contoller returns a Json result set. Trouble is, when I try to display a value in a joined db table, if there hasn't been a key value set, I get a nullreferenceexception error. Obviously I'm missing part of the puzzle here as there must be a way of coding this to stop it happening. Any help would be gratefully received!
My model is like this:
namespace TrainingKendoUI.Models
{
using System;
using System.Collections.Generic;
public partial class TRAINING_EMPLOYEE_COURSES
{
public int EMP_COURSE_ID { get; set; }
public int EMPLOYEE_ID { get; set; }
public int COURSE_ID { get; set; }
public Nullable<System.DateTime> DATE_ATTENDED { get; set; }
public Nullable<decimal> COURSE_COST { get; set; }
public string COURSE_RESITS { get; set; }
public Nullable<int> PROVIDER_ID { get; set; }
public Nullable<int> EMP_COURSE_STATUS_ID { get; set; }
public Nullable<int> VENUE_ID { get; set; }
public virtual TRAINING_COURSES TRAINING_COURSES { get; set; }
public virtual TRAINING_EMPLOYEE_COURSE_STATUS TRAINING_EMPLOYEE_COURSE_STATUS { get; set; }
public virtual TRAINING_EMPLOYEES TRAINING_EMPLOYEES { get; set; }
public virtual TRAINING_PROVIDERS TRAINING_PROVIDERS { get; set; }
public virtual TRAINING_VENUES TRAINING_VENUES { get; set; }
}
}
My controller method looks like this:
public JsonResult EmployeeCourses_Read()
{
var model = db.TRAINING_EMPLOYEE_COURSES;
var ViewModel = new List<EmployeeCoursesIntersectionViewModel>();
foreach (var employee in model)
{
ViewModel.Add(new EmployeeCoursesIntersectionViewModel(employee));
}
return Json(ViewModel, JsonRequestBehavior.AllowGet);
}
and my view model lilke this:
namespace TrainingKendoUI.ViewModels
{
public class EmployeeCoursesIntersectionViewModel
{
#region Constructors
public EmployeeCoursesIntersectionViewModel()
{
}
public EmployeeCoursesIntersectionViewModel(TRAINING_EMPLOYEE_COURSES model)
{
this.empCourseId = model.EMP_COURSE_ID;
this.employee = model.TRAINING_EMPLOYEES.FIRST_NAME;
this.course = model.TRAINING_COURSES.COURSE_NAME;
this.dateAttended = model.DATE_ATTENDED;
this.cost = model.COURSE_COST;
this.resits = model.COURSE_RESITS;
//These lines will produce a NullReference error if not set through the front end...
this.provider = model.TRAINING_PROVIDERS.PROVIDER_NAME;
this.status = model.TRAINING_EMPLOYEE_COURSE_STATUS.EMP_COURSE_STATUS;
this.venue = model.TRAINING_VENUES.VENUE_NAME;
}
#endregion
#region Properties
public int empCourseId { get; set; }
public string employee { get; set; }
public string course { get; set; }
public Nullable<System.DateTime> dateAttended { get; set; }
public Nullable<decimal> cost { get; set; }
public string resits { get; set; }
public string provider { get; set; }
public string status { get; set; }
public string venue { get; set; }
#endregion
}
}
Do a null check on the object before setting it, i.e.
this.provider = model.TRAINING_PROVIDERS == null ? ""
: model.TRAINING_PROVIDERS.PROVIDER_NAME;
and you'll have to do similar for status and venue
this.status = model.TRAINING_EMPLOYEE_COURSE_STATUS== null ? ""
model.TRAINING_EMPLOYEE_COURSE_STATUS.EMP_COURSE_STATUS;
this.venue = model.TRAINING_VENUES== null ? ""
model.TRAINING_VENUES.VENUE_NAME;
I have two models, a code model and a tag model which are linked by a many to many relationship. I am trying to add a code entry that includes a possible selection of many tags using a view model (using check boxes for the tags in my view). I am getting the error:
The model item passed into the dictionary is of type 'System.Collections.Generic.List'1[StoRed.Models.Code]', but this dictionary requires a model item of type 'System.Collections.Generic.IEnumerable`1[StoRed.Models.CodeTagViewModel]'.
It feels like I need to somehow convert my data to the acceptable format before trying to save it into the table but I'm new to MVC and I am having trouble finding any useful information on the internet about my specific problem. Any help would be greatly appreciated.
The code model
public class Code
{
[Key]
public int CodeID { get; set; }
[Required]
[StringLength(30)]
public string Title { get; set; }
[Required]
[StringLength(150)]
public string Description { get; set; }
public DateTime DateAdded { get; set; }
public DateTime LastUpdated { get; set; }
[Required]
[StringLength(30)]
public string Project { get; set; }
[Required]
[StringLength(30)]
public string CMS { get; set; }
public int DotNetVersion { get; set; }
[Required]
[StringLength(150)]
public string Dependencies { get; set; }
[StringLength(30)]
public string Author { get; set; }
public string CodeFile { get; set; }
[Required]
[StringLength(100)]
public string TFSLocation { get; set; }
////Creates a relationship in the DB with Tag
//[ForeignKey("TagID")]
public virtual ICollection<Tag> Tags { get; set; }
////Purely for API
//[Required]
public int TagID { get; set; }
}
The Tag model
public class Tag
{
[Key]
public int TagID { get; set; }
[Required]
[StringLength(30)]
public string TagName { get; set; }
public virtual ICollection<Code> Code { get; set; }
}
The context
public class Context : DbContext
{
public DbSet<Code> Code { get; set; }
public DbSet<Tag> Tags { get; set; }
}
The view model
public class CodeTagViewModel
{
public Tag Tag { get; set; }
public Tag TagID { get; set; }
public List<Tag> Tags { get; set; }
public int CodeID { get; set; }
public string Title { get; set; }
public string Description { get; set; }
public DateTime DateAdded { get; set; }
public DateTime LastUpdated { get; set; }
public string Project { get; set; }
public string CMS { get; set; }
public int DotNetVersion { get; set; }
public string Dependencies { get; set; }
public string Author { get; set; }
public string CodeFile { get; set; }
public string TFSLocation { get; set; }
}
Relevant part of the code controller
[HttpPost]
public ActionResult Create(CodeTagViewModel codeTagViewModel)
{
if (ModelState.IsValid)
{
Code code = new Code();
Tag tag = new Tag();
var codeTag = new CodeTagViewModel();
code.Title = codeTagViewModel.Title;
code.Description = codeTagViewModel.Description;
code.DateAdded = codeTagViewModel.DateAdded;
code.LastUpdated = codeTagViewModel.LastUpdated;
code.Project = codeTagViewModel.Project;
code.CMS = codeTagViewModel.CMS;
code.DotNetVersion = codeTagViewModel.DotNetVersion;
code.Dependencies = codeTagViewModel.Dependencies;
code.Author = codeTagViewModel.Author;
code.CodeFile = codeTagViewModel.CodeFile;
code.TFSLocation = codeTagViewModel.TFSLocation;
code.Tags = codeTagViewModel.Tags;
db.Code.Add(code);
db.SaveChanges();
return RedirectToAction("Index");
}
return View(codeTagViewModel);
}
Your best bet is to create some kind of provider/manager/service/factory/handler - choose a name that makes most sense in terms of the job it is doing within the flow of data through your system - that is responsible for taking the ViewModel and mapping the properties of the ViewModel into an instance of the domain model before persisting the domain model to the data store, either itself or by passing the hydrated domain model to a repository layer. You can either do this manually or by using something like AutoMapper. Here's a quick manual example:
Create a CommandHandlers folder in your web project with the interface and dependant handler:
public interface ICodeCommandHandler
{
int Save(CodeTagViewModel input);
}
public class CodeCommandHandler : ICodeCommandHandler
{
private IRepository<Code> repository;
public CodeCommandHandler(IRepository<Code> repository)
{
this.repository = repository;
}
public int Save(CodeTagViewModel input)
{
Code code = new Code();
Tag tag = new Tag();
code.Title = input.Title;
code.Description = input.Description;
code.DateAdded = input.DateAdded;
code.LastUpdated = input.LastUpdated;
code.Project = input.Project;
code.CMS = input.CMS;
code.DotNetVersion = input.DotNetVersion;
code.Dependencies = input.Dependencies;
code.Author = input.Author;
code.CodeFile = input.CodeFile;
code.TFSLocation = input.TFSLocation;
code.Tags.Add(tag);
return repository.Save(code);
}
}
Then in your controller, inject the ICodeCommandHandler in via constructor injection, the same as you do with the repository in the CodeCommandHandler:
private readonly ICodeCommandHandler commandHandler;
public CodeController(ICodeCommandHandler commandHandler)
{
this.commandHandler = commandHandler;
}
[HttpPost]
public ActionResult Create(CodeTagViewModel codeTagViewModel)
{
if (!ModelState.IsValid)
{
return View(codeTagViewModel);
}
var id = codeCommandHandler.Save(codeTagViewModel);
// maybe do something useful with the document id after save
return RedirectToAction("Index");
}
To keep the Repository nice and simple, here's how that could look:
public interface IRepository<T>
{
int Save(T entity);
}
public class CodeRepository : IRepository<Code>
{
public int Save(Code entity)
{
using (var context = new Context())
{
context.Code.Add(entity);
context.SaveChanges();
}
}
}
I've not gone into detail about the dependency injection side of things as that wasn't part of the question but this should give you an idea of where to start
I have a Controller action the receives 2 URL parameters, which are foreign keys for the data model:
public ActionResult Create(SurveyResponseModel surveyresponsemodel, int MemberId, int ProgramId)
{
surveyresponsemodel.MemberId = MemberId;
surveyresponsemodel.ProgramId = ProgramId;
return View(surveyresponsemodel);
}
Here is the data model:
public class SurveyResponseModel
{
[Key]
public int ResponseId { get; set; }
public int MemberId { get; set; }
public int ProgramId { get; set; }
// "If yes, what changes did you make? Mark all that apply."
[DisplayName("Did you make any changes in your practice, research, or administration activities as a result of participating in this CME activity?")]
public string CmeChanges { get; set; }
[DisplayName("Better patient follow-up")]
public bool PatientFollowUp { get; set; }
public virtual SurveyProgramModel SurveyProgramModel { get; set; }
public virtual PersonModel PersonModel { get; set; }
And the Data Model for "SurveyProgramType"
public class SurveyProgramModel
{
[Key]
public int ProgramId { get; set; }
public int ProgramYear { get; set; }
public int ProgramStatusId { get; set; }
public string ProgramTitle { get; set; }
public int ProgramTypeId { get; set; }
public virtual SurveyProgramTypeModel ProgramType { get; set; }
public virtual ProgramStatusModel ProgramStatusModel { get; set; }
}
What I want to be able to do in my view, is retrieve the ProgramTitle by the URL parameter that is passed for ProgramId. So the view looks something like:
<div class="editor-label">
#Model.SurveyProgramModel.ProgramTitle
</div>
However, #Model.SurveyProgramModel.ProgramTitle is throwing an exception because it is null. I'm thinking I have my navigation property set up incorrectly. Any idea what that is?
Shouldn't you return your view model to the view?
public ActionResult Create(
SurveyResponseModel surveyresponsemodel) //, int MemberId, int ProgramId)
{
// MemberId and ProgramId arguments do not need to be defined
// They will be picked up my MVC model binder, since there are properties
// with the same name in SurveyResponseModel class
//surveyresponsemodel.MemberId = MemberId;
//surveyresponsemodel.ProgramId = ProgramId;
surveyresponsemodel.SurveyProgramModel = new SurveyProgramModel(); // new line
return View(surveyresponsemodel); // <- return your view model here
}
without passing the model to the view, you cant access the properties of the model in your view. thats the possible cause of the error.
public ~ActionResult PassModel(DemoModel _model, int id)
{
// your code goes here....
return View(_model); // pass the model to view ..so you can work on your model
}
I have a model like the following:
public class TestViewModel
{
string UpdateProperty { get; set; }
string IgnoreProperty { get; set; }
ComplexType ComplexProperty { get; set; }
}
where
public class ComplexType
{
long? Code { get; set; }
string Name { get; set; }
}
My controller action:
public Edit(int id, FormColleciton formCollection)
{
var model = service.GetModel(id);
TryUpdateModel(model);
//...
}
When calling the Edit action I have a formCollection parameter containing only a key/value for UpdateProperty.
After the call to TryUpdateModel UpdateProperty is set correctly, IgnoreProperty is left un-touched but ComplexProperty is set to null, even if it previously had a value.
Should TryUpdateModel() only modify properties that are a part of the request? If this is not the case what is the best way to work around this so ComplexProperty is only modified if it is included in the request?
After it was pointed out by Darin that the test case above didn't demonstrate the problem I have added a scenario where this problem really occurs:
public class TestViewModel
{
public List<SubModel> List { get; set; }
}
public class SubModel
{
public ComplexType ComplexTypeOne { get; set; }
public string StringOne { get; set; }
}
public class ComplexType
{
public long? Code { get; set; }
public string Name { get; set; }
}
Controller Action:
public ActionResult Index()
{
var model = new TestViewModel
{
List = new List<SubModel> {
new SubModel{
ComplexTypeOne = new ComplexType{Code = 1, Name = "5"},
StringOne = "String One"
}
}
};
if (TryUpdateModel(model)) { }
return View(model);
}
Sending this request:
/Home/Index?List[0].StringOne=test
updates SubModel.StringOne property but sets ComplexTypeOne to null, even though it is not included in the request.
Is this expected behaviour (given this does not happen unless an enumerable of complex types is used)? How best to work around this?
There must be something wrong with your test case as I was unable to reproduce it. Here's what I tried:
Model (notice that I use public properties):
public class TestViewModel
{
public string UpdateProperty { get; set; }
public string IgnoreProperty { get; set; }
public ComplexType ComplexProperty { get; set; }
}
public class ComplexType
{
public long? Code { get; set; }
public string Name { get; set; }
}
Controller:
public class HomeController : Controller
{
public ActionResult Index()
{
var model = new TestViewModel
{
IgnoreProperty = "to be ignored",
UpdateProperty = "to be updated",
ComplexProperty = new ComplexType
{
Code = 1,
Name = "5"
}
};
if (TryUpdateModel(model))
{
}
return View();
}
}
Now I send the following request: /home/index?UpdateProperty=abc and inside the condition only the UpdateProperty is modified with the new value from the query string. All other properties, including the complex property, are left untouched.
Also notice that the FormCollection action parameter is useless.