How to supply dynamic data set to a single view using ViewModels

Question

(first time posting and fairly new to MVC) I currently have a MVC/C# application where the user selects a list of ID's and then chooses a Report Type (8 possible different reports calling 8 different database views). I am passing all of these parameters to the controller. Based on the report type chosen, I want to fetch the data, send it back to the view and then display the data in a grid/table format.

I tried sending the data via ViewBag and ViewData but had trouble parsing the actual columns/data using @foreach. This is when I decided to try ViewModels.

//My ViewModel....
//I know that I am missing the {get;set;} code which is where I also
// need help with.  I need to pass the selected ID's to each database view and 
// perform additional query requests (i.e. Distinct, Order By). 
// Sample query:
// var dd = (from p in _db.Report1 select new { sId = p.ReportID, UserName = p.Submitted_By, 
//      Balance = p.TotalDebt}).Distinct();
// dd = dd.Where(w => chosenUserIDs.Contains(w.sID));
// dd.OrderBy(p => p.sId).ThenBy(p => p.UserName).ThenBy(p => p.Balance);

public class UserReportsViewModel
{
    public List<namespace.report1> Report1 = new List<namespace.report1>();
    public List<namespace.report2> Report2 = new List<namespace.report2>();
    public List<namespace.report3> Report3 = new List<namespace.report3>();
    ...
}

//My Controller
UserReportsViewModel UserReportVM = new UserReportsViewModel();
switch (reportType)
{
    case "REPORT1":
        //Pass the selected ID's and get the data back from Report1 db view
        // not quite sure how to do this.
        break;
    case "REPORT2":
        break;
    case "REPORT3":
        break;
    default:
        break;
}
return View(UserReportsVM);

Am I even on the right track? I also came across something about partial Views and having the View call/referrence the correct partial View (?). Older languages were a lot simpler to accomplish this but I am really liking MVC/.Net/C#.

As for my database, I am using CodeFirst Entity framework.

Answer 1

I highly suggest you have view, viewmodel and action for each report. Just call the correct endpoint based on the requested report in the client.

Or, if you want to do this with one endpoint (action) specify the view you want to return. If you don't specify the view name, it returns a view based on the action name, but you can specify the view to render.

return View("ViewToRender", viewModel);

If you want to get fancy, you could do this with one view. Include a layout object in the viewmodel with the data... this way you can use one view model. The layout would be a list of "column info fields". Column1 would have This header, this width, etc. It would be bound to GenericReportViewModel.Column1.

From there, you just need to project your data into that generic view model.

Answer 2

Each model will return unique data with unique set of columns.comments by the user above

If this is the case write the logic in the view like this

@if(model.Report1!=null && model.Report1.Count!=0){
 // your logic for report1 goes here or you can also use partial view to render
 } 
else if(model.Report2!=null && model.Report2.Count!=0)

{ 
// your logic for report2 goes here or you can also use partial view to render
} 

Same for all the other reports. Hope this will help

Answer 3

Thank you all for your help and guidance. I decided to to Partial Views. The solution to my question is as follows.

For each report, I get the data and immediately store the data into ViewData.

IQueryable<dbViewName> Report8 = _db.dbViewName;
ViewData["qryResults"] = Report8;
...
return View(ViewData["qryResults"]);

Then in the main view I call the partial view:

@Html.RenderPartial(rt, ViewData["qryResults"]);

In the partial view my model is strong type.

@model IQueryable<dbViewName>

This allowed me to list out the data in tables by using:

@foreach (var item in Model)

It is clean and easy to implement any additional reports that the client may request in the future.

Again, thank you all for your input.