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Accept a list of objects from form data in ASP.NET Core

I am currently struggling to accept a list of objects from FormData in ASP.NET Core.
The project looks like this:
I have a class called Stavka (English: Item).
public class Stavka
{
public string naziv { get; set; }
public double cenaPoJedinici { get; set; }
public string jedinicaMere { get; set; }
public int kolicina { get; set; }
public Stavka(string naziv, double cenaPoJedinici, string jedinicaMere, int kolicina)
{
this.naziv = naziv;
this.cenaPoJedinici = cenaPoJedinici;
this.jedinicaMere = jedinicaMere;
this.kolicina = kolicina;
}
public Stavka()
{
}
}
I have a class called Faktura (English: Bill) which has a variable called Stavke (English: Items) that is a list containing the Stavka objects.
public class Faktura
{
public int Id { get; set; }
public string pibStart { get; set; }
public string pibEnd { get; set; }
public DateTime datumGen { get; set; }
public DateTime datumRok { get; set; }
public List<Stavka> stavke { get; set;}
public double cena { get; set; }
public string tip { get; set; }
public Faktura(int id, string pibStart, string pibEnd, DateTime datumGen, DateTime datumRok, List<Stavka> stavke, string tip)
{
Id = id;
this.pibStart = pibStart;
this.pibEnd = pibEnd;
this.datumGen = datumGen;
this.datumRok = datumRok;
this.stavke = stavke;
this.tip = tip;
double sumCena = 0;
foreach(Stavka s in stavke)
{
sumCena += s.kolicina * s.cenaPoJedinici;
}
this.cena = sumCena;
}
public Faktura()
{
}
I want to create a new Faktura object and add it to a list within my Controller. I tried to do this with the following code:
[HttpPost("dodajFakturu")]
public IActionResult dodajFakturu([FromForm]string pibStart, [FromForm]string pibEnd,[FromForm]DateTime datumStart, [FromForm]DateTime datumEnd,[FromForm]List<Stavka> stavkeLis, [FromForm]string tip)
{
int id = lst.OrderByDescending(p => p.Id).First().Id + 1;
Faktura f = new Faktura(id, pibStart,pibEnd, datumStart,datumEnd,stavkeLis,tip);
lst.Add(f);
return Ok(SveFakture());
}
And yet, when i post the request (in Swagger/Postman), the variable stavkeLis (which accepts the JSON array) is always empty:
This is certainly because i fundamentally misunderstood the way in which NET Core accepts these variables.
Is there some other way to send a list of objects through form data?

this way you have is currect, but if its not maybe because simple code problem but way that you right the code can be better or you can say develop your code as Below:
// StavkaBody => I Mean All Body In One Json
public async Task<IActionResult> MethodName([FromForm] string
StavkaBody)
{
YourObjectType object = new YourObjectType();
// this will be Populate All Json To Single object And
// You dont Need To Add some Constructors For Done this
JsonConvert.PopulateObject(StavkaBody, objec);
// Example Usage
Console.WriteLine(object.Name);
}
in Here I`ve Used The Newtonsoft.Json For this And Its Make Your Model So Much Simpler.
I Hope Its Helps

Separate Model with List

I want to return a list of links to a web page when it loads. Right now I have a model called SsoLink.cs bound to the page. I would like to return a list, so I have created another model called SsoLinks.cs that has a List. In my helper function, I keep getting "object not set to an instance of an object".
SsoLink.cs
public class SsoLink
{
public enum TypesOfLinks
{
[Display(Name="Please Select a Type")]
Types,
Collaboration,
[Display(Name="Backups & Storage")]
Backups_Storage,
Development,
[Display(Name="Cloud Services")]
Cloud_Services,
[Display(Name="Human Resources")]
Human_Resources,
Analytics
}
public string Id { get; set; }
public string Name { get; set; }
public string Url { get; set; }
public string Owner { get; set; }
public string OwnerEmail { get; set; }
public string LinkDescription { get; set; }
public TypesOfLinks LinkType { get; set; }
}
SsoLinks.cs
public class SsoLinks
{
public List<SsoLink> Links {get; set;}
}
GetLinksHelper.cs
public partial class SsoLinkHelper
{
public static SsoLinks GetLinks()
{
var ssoList = new SsoLinks();
try
{
//search the index for all sso entries
var searchResponse = _client.Search<SsoLink>(s => s
.Index(_ssoLinkIndex)
.Size(500)
.Query(q => q
.MatchAll()
)
);
if (searchResponse.Documents.Count == 0)
{
return ssoList;
}
ssoList.Links.AddRange(searchResponse.Hits.Select(hit => new SsoLink() {Id = hit.Source.Id, Name = hit.Source.Name, Url = hit.Source.Url, Owner = hit.Source.Owner}));
return ssoList;
}
catch (Exception e)
{
Log.Error(e, "Web.Helpers.SsoLinkHelper.GetLinks");
return ssoList;
}
}
}
While debugging, It is failing at SsoLinks.Links.AddRange(etc). How can I add a new SsoLink to the ssoList for every item found in my query?
Edit: Here is a screenshot of the error while debugging.

The null reference exception looks like it comes from ssoList.Links being null when calling AddRange on it, so it needs to be initialized to a new instance of List<SsoLink> before calling AddRange().

Russ's answer led me down the right path, I ended up just needing to change my view to:
#model List<SharedModels.Models.SsoLink>
rather than
#model SharedModels.Models.SsoLink
and do away with the SsoLinks model.

New class selected by LINQ query, how to transfer to another model?

I'm really not understanding this as I've only dabbled in MVC and C#. I apologize if my terminology is wrong or confusing, I will do my best to answer questions. I have a couple models like so:
public class DataSharingModels
{
public string ReferenceID { get; set; }
public NBTC NBTCGroup { get; set; }
public Contractors ContractorsGroup { get; set; }
public Coordinators CoordinatorsGroup { get; set; }
public NGO NGOGroup { get; set; }
public Public PublicGroup { get; set; }
public SelectList FA_RA_List { get; set; }
}
public class NBTC
{
public String NBTC_FA_Centroid { get; set; }
public String NBTC_FA_Bound { get; set; }
public String NBTC_RA_Centroid { get; set; }
//more properties...
}
The DataSharingModels class contains the public NBTC NBTCGroup property. It is not public List<NBTC> NBTCGroup because there will only be one produced per instance of the controller being hit.
Now in my controller, I have a LINQ statement that selects a new NBTC class:
var nbtcVals = (from ds in db.SharingPermissions
where ds.FocalRefID.ToString() == ReferenceID
&& ds.ShareGroup == "NBTC"
select new NBTC
{
NBTC_FA_Centroid = ds.CIP_FA_Centroid,
NBTC_FA_Bound = ds.CIP_FA_Boundary,
NBTC_RA_Centroid = ds.CIP_RA_Centroid,
//more properties...
});
Where I'm going wrong is I would like to add that to my DataSharingModels model. I thought the nbtcVals type would be NBTC, but it's IQueryable<##.Models.NBTC>. I understand I could do this, but it seems redundant:
DataSharingModels dsm = new DataSharingModels();
if (nbtcVals.Any())
{
foreach (var i in nbtcVals)
{
dsm.NBTCGroup.NBTC_FA_Centroid = i.NBTC_FA_Centroid;
dsm.NBTCGroup.NBTC_FA_Boundary = i.NBTC_FA_Bound;
dsm.NBTCGroup.NBTC_RA_Centroid = i.NBTC_RA_Centroid;
//more properties...
}
}
What is a more direct way to do this? There must be one. I supposed I could also return an anonymous type in the LINQ query and then assign each property in the foreach like dsm.NBTCGroup.NBTC_RA_Centroid = i.NBTC_RA_Centroid but that seems the same as the other way.

var nbtcgroup = (from ds in db.SharingPermissions
where ds.FocalRefID.ToString() == ReferenceID
&& ds.ShareGroup == "NBTC"
select new NBTC
{
NBTC_FA_Centroid = ds.CIP_FA_Centroid,
NBTC_FA_Bound = ds.CIP_FA_Boundary,
NBTC_RA_Centroid = ds.CIP_RA_Centroid,
//more properties...
})
.OrderByDescending(n => n.Id) // or some other property that could identify sorting
.FirstOrDefault();
This one has a translation to SQL (LIMIT or TOP depending on backend).

Nesting list in model and the viewing and storing data

Sorry if this is a simple question but if I want to have a list inside a model, and later access and set the values of the list?
Say my main model looks like this:
public class StartPageModel : IPageViewModel<StartPage>
{
public IList<ListContent> ListContent { get; set; }
public StartPage CurrentPage { get; set; }
}
public class ListContent
{
public IList<ListElement> ArticleListContent { get; set; }
public IList<ListElement> InsightListContent { get; set; }
}
How can I set the ArticleListContent list to a value by referencing the parent model?
public ActionResult Index(StartPage currentPage)
{
var model = new StartPageModel(currentPage);
model.ListContent.ArticleListContent = GetListContent(currentPage.ArticleCollection);
}
However this returns the error:
IList does not contain a definition for 'ArticleListContent'

I'm not sure you require a collection of ListContent in your StartPageModel, correct me if I'm wrong.
Change
public IList<ListContent> ListContent { get; set; }
to
public ListContent ListContent { get; set; }
And provided ListContent is initialized, your assignment will work.

It's because it's referencing the List of ListContent, not an individual item in that list. Here's some examples:
var model = new StartPageModel(currentPage);
model.ListContent[0].ArticleListContent = GetListContent(currentPage.ArticleCollection); // Access first in list
model.ListContent[1].ArticleListContent = GetListContent(currentPage.ArticleCollection); // Access secondin list
model.ListContent.First().ArticleListContent = GetListContent(currentPage.ArticleCollection); // Access first in list using Linq

MVC3 linq joins

As a novice am trying my hands on MVC3,razor, EF I have Three connected Tables that I want to produce a view from it. In a simpleton's brief the following are about the tables
PJUsers - ID, memUID(this unique Id from membership),FirstName,LastName
PJAwards - user nominates another user for an award, this links with awardtypesID as foreign key ( awardId,bool:awardok)
PJAwartypes - (awardtypeID, awardName)
The query in the controller is like this
var lists =
from tl in db.PJawards
join u in db.PJUsers on tl.nomineeId equals u.ID into tl_u
join i in db.PJUsers on tl.nominatorId equals i.MemUID into tl_i
where tl.awardOk
orderby tl.awardDated ascending
from u in tl_u.DefaultIfEmpty()
from i in tl_i.DefaultIfEmpty()
select new
{
Status = tl.awardOk,
nomineeFname = u.FirstName,
nomineeLname = u.LastName,
award = tl.PJawards.awardName,
Dated = tl.awardDated,
nominatorFname = i.FirstName,
nominatorLname = i.LastName,
nomineeCountry = u.Citizen,
nomineeResidence = u.Residence,
awardtypeId = tl.ID
};
somewhere i read that i have to construct a model class similar to the query in the controller
{
public class AwardUserInfo
{
public AwardUserInfo() { }
public bool Status { get; set; }
public string nomineeFname { get; set; }
public string nomineeLname { get; set; }
public string award { get; set; }
public string Dated { get; set; }
public string nominatorFname { get; set; }
public string nominatorLname { get; set; }
public string nomineeCountry { get; set; }
public string nomineeResidence { get; set; }
public int awardtypeId { get; set; }
}
}
Please I learn by examples so to be able to help me assume I don't know anything

somewhere i read that i have to construct a model class similar to the query in the controller
Try this.
I guess your ef-model is similar to
So You can create a ViewModel class
public class PJAwardsViewModel
{
public int Id { get; set; }
public string NominatorFName { get; set; }
public string NomineeFname { get; set; }
public string AwardName { get; set; }
public bool IsAwarded { get; set; }
}
It will be also good if You add some service class
public class PJAwardsService
{
public static List<PJAwards> GetAll()
{
using (var context = new YourDBEntities())
{
return context.PJAwards
.Include(x => x.PJUsers)
.Include(x => x.PJUsers1)
.Include(x => x.PJAwartypes).ToList();
}
}
}
(Don't forget to write using System.Data.Entity; )
Then You can add a ViewModelHelper class
public class PJAwardsViewModelHelper
{
public static PJAwardsViewModel PopulatePJAwardsViewModel(PJAwards pjaward)
{
return new PJAwardsViewModel
{
Id = pjaward.Id,
NominatorFName = pjaward.PJUsers.FirstName,
NomineeFname = pjaward.PJUsers1.FirstName,
AwardName = pjaward.PJAwartypes.AwardName,
IsAwarded = pjaward.IsAwarded
};
}
public static List<PJAwardsViewModel> PopulatePJAwardsViewModelList(List<PJAwards> pjawardsList)
{
return pjawardsList.Select(x => PopulatePJAwardsViewModel(x)).ToList();
}
}
At the end Your controller index method will look like this
public ActionResult Index()
{
var pjawards = PJAwardsViewModelHelper.PopulatePJAwardsViewModelList(PJAwardsService.GetAll().ToList());
return View(pjawards);
}
The only thing You should do is add a view (build the project before). Choose PJAwardsViewModel as a Model class and List as a scaffold template.
Enjoy it.

Here is a step by step guide by Steven Sanderson on how to use Asp.net MVC3, EF Code First with MVCScaffolding (powershell automation).
http://blog.stevensanderson.com/2011/01/13/scaffold-your-aspnet-mvc-3-project-with-the-mvcscaffolding-package/
It is a multipart blog post takes you through the exciting journey of MVC3.
All the best.