Insert 1 parent row and many child rows Asp.net MVC - asp.net-mvc

Question

So I am creating a system where you can create forms and store them in the database which will be displayed for specific types of reports.
On a report you will be entering 1 row into the Report table with the default report data like report owner, submission date, status etc
On this same create page I would like to have all of the values from the created form that's stored in the DB, so far I have managed to get the displayed form to show correctly with the report.
Each input for the form in the DB will be 1 entry into the ReportValues table.
Currently I can get the Report from the Create View but the entries for ReportValue are not being returned to the Create Iaction.
Please help :/
Models:
public class Report
{
public Report()
{
//Set default Submission Date to the current date.
this.SubmissionDate = DateTime.Now;
this.Status = "New";
}
public int ID { get; set; }
[ForeignKey("Form")]
public int formID { get; set; }
[StringLength(5, MinimumLength = 3)]
public String Abreviation { get; set; }
[Display(Name = "Submitted By")]
public String Owner { get; set; }
[RegularExpression(#"^[A-Z]+[a-zA-Z''-'\s]*$")]
public String Category { get; set; }
public String Status { get; set; }
[DataType(DataType.Date), Display(Name = "Submit Date")]
public DateTime SubmissionDate { get; set; }
}
}
public class ReportValues
{
public int ID { get; set; }
[ForeignKey("Report")]
public int reportId { get; set; }
public String title { get; set; }
public String value { get; set; }
}
}
public class FormReportViewModel
{
public Report Report { get; set; }
public int reportID { get; set; }
public String formCode { get; set; }
public String abv { get; set; }
public String category { get; set; }
public IEnumerable<ReportValues> ReportValues { get; set; }
}
}
Create Iaction:
// POST: Reports/Create
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Create(FormReportViewModel formReportViewModel)
{
Report r = formReportViewModel.Report;
if (ModelState.IsValid)
{
_context.Report.Add(r);
_context.SaveChanges();
foreach (var item in formReportViewModel.ReportValues)
{
ReportValues rv = new ReportValues { reportId = r.ID, title = item.title, value = item.value };
_context.ReportValues.Add(rv);
_context.SaveChanges();
}
return RedirectToAction("Index");
}
return View(formReportViewModel);
}
View:
model IEnumerable<FormReportViewModel>
#using System.Security.Claims;
#{
ViewData["Title"] = "Create";
}
<h2>Create</h2>
<form asp-action="Create">
<div class="form-horizontal">
<h4>Report</h4>
<hr />
<div asp-validation-summary="ValidationSummary.ModelOnly" class="text-danger"></div>
<div class="form-group">
<label asp-for="#Model.First().Report.Abreviation" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="#Model.First().Report.Abreviation" class="form-control" value="#Model.First().abv" readonly="readonly"/>
<span asp-validation-for="#Model.First().Report.Abreviation" class="text-danger" />
</div>
</div>
<div class="form-group">
<label asp-for="#Model.First().Report.Category" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="#Model.First().Report.Category" class="form-control" value="#Model.First().category" readonly="readonly"/>
<span asp-validation-for="#Model.First().Report.Category" class="text-danger" />
</div>
</div>
<div class="form-group">
<label asp-for="#Model.First().Report.Owner" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="#Model.First().Report.Owner" class="form-control" value=#User.GetUserName() readonly="readonly"/>
<span asp-validation-for="#Model.First().Report.Owner" class="text-danger" />
</div>
</div>
<div class="form-group">
<label asp-for="#Model.First().Report.Status" class="col-md-2 control-label"></label>
<div class="col-md-10">
<input asp-for="#Model.First().Report.Status" class="form-control" value="New" readonly="readonly"/>
<span asp-validation-for="#Model.First().Report.Status" class="text-danger" />
</div>
</div>
#*Html.Raw(Model.First().formCode)*#
#*
The code below is from the Create ReportValues page
*#
<div class="form-group">
<label class="col-md-2 control-label" for="title">title</label>
<div class="col-md-10">
<input class="form-control" type="text" id="title" name="title" value="Animal Name" />
<span class="text-danger field-validation-valid" data-valmsg-for="title" data-valmsg-replace="true" />
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="value">value</label>
<div class="col-md-10">
<input class="form-control" type="text" id="value" name="value" value="" />
<span class="text-danger field-validation-valid" data-valmsg-for="value" data-valmsg-replace="true" />
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="title">title</label>
<div class="col-md-10">
<input class="form-control" type="text" id="title" name="title" value="Animal Weight" />
<span class="text-danger field-validation-valid" data-valmsg-for="title" data-valmsg-replace="true" />
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="value">value</label>
<div class="col-md-10">
<input class="form-control" type="text" id="value" name="value" value="" />
<span class="text-danger field-validation-valid" data-valmsg-for="value" data-valmsg-replace="true" />
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="title">title</label>
<div class="col-md-10">
<input class="form-control" type="text" id="title" name="title" value="Animal Colour" />
<span class="text-danger field-validation-valid" data-valmsg-for="title" data-valmsg-replace="true" />
</div>
</div>
<div class="form-group">
<label class="col-md-2 control-label" for="value">value</label>
<div class="col-md-10">
<input class="form-control" type="text" id="value" name="value" value="" />
<span class="text-danger field-validation-valid" data-valmsg-for="value" data-valmsg-replace="true" />
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
</form>
<div>
<a asp-action="Index">Back to List</a>
</div>

Answer 1

From the comments: you have a NRE in FormReportViewModel, ReportValues is null.
Change IEnumerable<ReportValues> to List<ReportValues>, add a constructor in FormReportViewModel and create an instance of ReportValues
public class FormReportViewModel
{
public Report Report { get; set; }
public int reportID { get; set; }
public String formCode { get; set; }
public String abv { get; set; }
public String category { get; set; }
public List<ReportValues> ReportValues { get; set; }
public FormReportViewModel()
{
ReportValues=new List<ReportValues>();
}
}