// Recall that the @Html.TextBoxFor returns the data collected, stored in a field of the view model class type
// Also recall that interactions with the View are handled by the HttpPost attribute - passing in a view model
// as the parameter allows the action method to make use of the data stored in the vm that is returned.
// However, the compiler calls the default constructor when creating an instance of the vm object to be passed in,
// so ensure that whichever fields are required within the vm have a default constructor.
// Post data to the server side, to be processed by the database.
public ActionResult AddCourse(StudentGradesViewModel vm)
{
StudentGradeDAL studentGradeDAL = new StudentGradeDAL();
// Poll for clicks from btnCreate
// Request tracks any requests made from the current View
// .Form[string name] specifies the NAME of the form control to track requests from.
// If the button matching the specified name is clicked, its value gets returned. If no click
// event occurs, btnAdd will return null. Thus, when it is idle, the else block runs.
if (Request.Form["btnCreate"] != null)
{
// The following is incorrect. Why create a new Grade with the same values as the current Grade???
//studentGradeDAL.GradeBook.Add(new Grade(vm.Grade.CourseTitle, vm.Grade.Passed));
// This checks if any errors exist on the server side (basically any attributes like [RegularExpression] that
// are not satisfied)
if (ModelState.IsValid)
{
// The Grade object is created and populated based on the entries in the form - just add to Gradebook.
studentGradeDAL.GradeBook.Add(vm.Grade);
// Without this, any changes will not be reflected in the database.
studentGradeDAL.SaveChanges();
// RedirectToAction redirects away from the current webpage. Parameters are the name of the
// action method to redirect to, followed by the name of the Controller the action method
// belongs to, both represented as strings.
return(RedirectToAction("ResultsStatement", "Day2Demo"));
}
// If the above check fails, the same View is returned. B nnecause the error messages are specified in Grade.cs, as
// well as instructed to show in AddCourse.cshtml, they will display on the screen this time round.
return(View());
}
else if (Request.Form["btnCancel"] != null)
{
return(RedirectToAction("ResultsStatement", "Day2Demo"));
}
else
{
// Return the same view if no buttons are pressed.
return(View());
}
}
// GET: Day2Demo
public ActionResult ResultsStatement()
{
// Instantiating an object of the View Model
StudentGradesViewModel studentGradesViewModel = new StudentGradesViewModel();
// Creating a student object - this is the Model that will be used within the View Model
Student crazyHoe = new Student("Crazy Hoe", 3, "MMSC - Magical Mysterious Science College");
// Populate the View Model's student field with the instance of Student created above.
studentGradesViewModel.Student = crazyHoe;
//// Hard-code the elements of the View Model's gradebook field
//studentGradesViewModel.GradeBook.Add(new Grade("DADA330/Defense Against the Dark Arts", true));
//studentGradesViewModel.GradeBook.Add(new Grade("CLHC120/Fine Wines of the World", true));
//studentGradesViewModel.GradeBook.Add(new Grade("WHEE420/Diabetes Synthesis and Dissolution", false));
//studentGradesViewModel.GradeBook.Add(new Grade("MATH520/Thesis in Stupidity", false));
//studentGradesViewModel.GradeBook.Add(new Grade("IGME106/mAgIc mAKeR sTuDIo", true));
//studentGradesViewModel.GradeBook.Add(new Grade("FREE333/Free Real Estate", true));
// Instantiate the DAL wherever it is needed - in this case, to read from and print to the screen.
StudentGradeDAL studentGradeDAL = new StudentGradeDAL();
// .ToList creates and returns a list from the specified gradebook entry. Assign Gradebook within the
// DAL to this list.
studentGradesViewModel.GradeBook = studentGradeDAL.GradeBook.ToList();
// Changing display ResultColour of Grade Passed string
// This is done in the controller because it has direct access to the GradeBook List of Grade objects.
foreach (Grade grade in studentGradesViewModel.GradeBook)
{
grade.ResultColor = grade.Passed.ToLower() == "pass" ? "color:Green" : "color:Red";
}
// Pass the View Model object into the View upon returning it, so all its class fields can be utilised.
// As always, not specifying string viewName will cause VS to look for a View whose name matches that
// of the method name - in this case ResultsStatement.
return(View(studentGradesViewModel));
}
