MVC5: Custom validations are not triggered when Submit button is clicked - data-annotations

Question

I am creating a selection screen, let say there are two fields "Start Date" and "End Date" and a "Search" button.
I created custom attribute for validating the date fields such that it must fall within a dynamic date range:
public class YearTimeFrameAttribute : ValidationAttribute
{
private DateTime _minDate;
public YearTimeFrameAttribute(int timeFrameInYear)
{
int _timeFrame = Math.Abs(timeFrameInYear) * -1;
_minDate = DateTime.Now.AddYears(_timeFrame);
}
public override bool IsValid(object value)
{
DateTime dateTime = Convert.ToDateTime(value);
if (dateTime < _minDate)
{
return false;
}
else
{
return true;
}
}
public override string FormatErrorMessage(string name)
{
return String.Format("The field {0} must be >= {1}", name, _minDate.ToString("dd/MM/yyyy"));
}
}
Below is the code in the selection screen model:
public class SelectionParametersModel
{
[YearTimeFrame(7)]
[DataType(DataType.Date)]
[Display(Name = "Extraction Start Date")]
public DateTime StartDate { get; set; }
[YearTimeFrame(7)]
[DataType(DataType.Date)]
[Display(Name = "Extraction End Date")]
public DateTime EndDate { get; set; }
}
Finally my controller do this (I am trying to return a file):
// GET: /SelectionScreen/
public ActionResult SelectionScreen()
{
ViewBag.Title = "Selection Screen";
return View();
}
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult SelectionScreen(SelectionParametersModel selectionParameter)
{
... Code to build report ...
string mimeType;
Byte[] renderedBytes;
Functions.GenerateReport(out renderedBytes, out mimeType);
return File(renderedBytes, mimeType);
}
So I input a wrong date in the start/end date fields and click "Search", the program just ignore the validations and generate the file.
(Note: I haven't paste all my code here to keep thing simpler, but I have proved that the date validation logic is correct.)

Answer 1

Sorry that I find my solution shortly after posting the question. (I am really new in MVC)
I find that I should include "if (ModelState.Isvalid)" in the HttpPost method.
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult SelectionScreen(SelectionParametersModel selectionParameter)
{
if (ModelState.IsValid)
{
... Code ....
}
return View();
}