trjhtr

I want to create page when user can use form to display filtered data in table. Form has to remember its own state, because after every refresh it shouldnt change.

So after submitting form I should get:

• form values


• results from database based on what was checked in form

Seems pretty easy.

• HistoryViewModel thats all data I want to display to user




• HistorySearchResult thats view model for table content




• HistorySearchCriteria contains filtering options in form




• HistorySearchBusinessLogic.GetHistories(HistorySearchCriteria
searchModel) I am using this to get data from database but with
  filtering applied.

At first I created my ViewModel which will holds data to display:

public class HistoryViewModel

 // form's filtering options here
 public HistorySearchCriteria HistorySearchCriteria get; set; 

 // results after filtering
 public List<HistorySearchResult> HistorySearchResults get; set; 

 // entries amount (needed for pagination)
 public int AmountOfEntries get; set; 

 // avaible actions to modify row's data. For example on particular page only `delete` and `edit` will be possible
 public List<SiteEnums.GroupActionOptions> GroupActions get; set; 

Now, let me give you a quick peek of HistorySearchCriteria. I am using this to get values from filtering form.

public class HistorySearchCriteria

 [DisplayFormat(DataFormatString = "0:dd.MM.yyyy", ApplyFormatInEditMode = true)]
 public DateTime? DateFrom get; set; 

 [DisplayFormat(DataFormatString = "0:dd.MM.yyyy", ApplyFormatInEditMode = true)]
 public DateTime? DateTo get; set; 

 public int? AmountFrom get; set; 
 public int? AmountTo get; set; 

 public string Title get; set; 

 public List<SelectListItem> Banks get; set; 
 public string SelectedBankId get; set; 

 public List<SelectListItem> Statuses get; set; 
 public int? SelectedStatusId get; set; 

 public SiteEnums.ShowOptions Display get; set; 
 public int? SelectedDisplayId get; set; 

After making POST I am retreiving data from filtering form and using that data to fill another ViewModel:

[HttpPost]
public ActionResult Index(HistoryViewModel searchViewModel, int page = 0, int resultsAmount = 100)

 var logic = new HistorySearchBusinessLogic();

 // get data based on filtering options
 var query = logic.GetHistories(searchViewModel.HistorySearchCriteria);

 // do some validation
 if (page < 0) page = 0;
 if (resultsAmount < 0) resultsAmount = 100;

 // get data amount
 var amount = query.Count();

 // get ONLY important data
 var results = query.
 OrderBy(x => x.Id)
 .Skip(page * resultsAmount)
 .Take(resultsAmount)
 .Select(x => new HistorySearchResult
 
 Amount = ((double)x.Amount / 100).ToString(),
 Bank = x.Bankaccount.BankShort.BankShortName,
 CustomerData = x.CustomerData,
 OperationDate = x.DateIncoming,
 SaveDate = x.DateExecutive,
 Title = x.Title
 )
 .ToList();

 // fill view model
 var viewModel = new HistoryViewModel()
 
 HistorySearchCriteria = searchViewModel.HistorySearchCriteria,
 HistorySearchResults = results,
 GroupActions = new List<SiteEnums.GroupActionOptions>()
 ;

 // pass data with RPG design pattern
 TempData["viewModelFromPost"] = viewModel;
 return RedirectToAction("Index");

Now in TempData["viewModelFromPost"] I should have data which holds my filtering criteria, results etc.

In GET I have 2 scenarions:

• 
  TempData["viewModelFromPost"] can be null, because thats my first
  request TempData["viewModelFromPost"] can contains data results,
  filtering criteria etc.

Lets see whats inside GET

[HttpGet]
public ActionResult Index()

 HistoryViewModel vm = new HistoryViewModel();

 if (TempData["viewModelFromPost"] != null)
 
 vm = TempData["viewModelFromPost"] as HistoryViewModel;
 
 else
 
 vm.HistorySearchCriteria = new HistorySearchCriteria()
 
 DateFrom = DateTime.Now,
 DateTo = DateTime.Now,
 ;

 vm.HistorySearchResults = new List<HistorySearchResult>();
 

 vm.GroupActions = new List<SiteEnums.GroupActionOptions>();

 vm.HistorySearchCriteria.Banks = _context.BankShortTypes.Select(x => new SelectListItem
 
 Text = x.BankShortName,
 Value = x.Id.ToString()
 ).ToList();

 vm.HistorySearchCriteria.Statuses = _context.StatusTypes.Select(x => new SelectListItem
 
 Text = x.StatusName,
 Value = x.Id.ToString()
 ).ToList();


 return View(vm);

Well, its complicated a bit. I think controllers should be lighter. What do you think about that? I think that could be archived much, much easier. It starting to be very complicated in GET, because I have to remeber which List I have to initialie, which data I have to get from database etc.

I think that pipeline pattern for filtering in connection with GET request will be a good way to go.

See details over here: Pipeline pattern for .Net

Just separate filtering as a separate service and pass around here checked by users params to filter.