public async Task <IActionResult> OnPostAsync(string[] selectedCourses)
{
var newInstructor = new InstructorWithCollection();
if (selectedCourses != null)
{
newInstructor.Courses = new List <Course>();
foreach (var course in selectedCourses)
{
newInstructor.Courses.Add(_courses.Single(c => c.CourseID == int.Parse(course)));
}
}
#region snippet_TryUpdate
if (await TryUpdateModelAsync <InstructorWithCollection>(
newInstructor,
"Instructor",
i => i.FirstMidName, i => i.LastName, i => i.HireDate))
{
_instructorsInMemoryStore.Add(newInstructor);
return(RedirectToPage("./Index"));
}
PopulateAssignedCourseData(newInstructor);
return(Page());
#endregion
}
public IActionResult OnGet()
{
var instructor = new InstructorWithCollection();
instructor.Courses = new List <Course>();
// Provides an empty collection for the foreach loop
// foreach (var course in Model.AssignedCourseDataList)
// in the Create Razor page.
PopulateAssignedCourseData(instructor);
Instructor = instructor;
return(Page());
}
public IActionResult OnGet(int?id)
{
if (id == null)
{
return(NotFound());
}
Instructor = _instructorsInMemoryStore.FirstOrDefault(m => m.ID == id);
if (Instructor == null)
{
return(NotFound());
}
PopulateAssignedCourseData(Instructor);
return(Page());
}
public void PopulateAssignedCourseData(InstructorWithCollection instructor)
{
var allCourses = _courses;
var instructorCourses = new HashSet <int>(
instructor.Courses.Select(c => c.CourseID));
AssignedCourseDataList = new List <AssignedCourseData>();
foreach (var course in allCourses)
{
AssignedCourseDataList.Add(new AssignedCourseData
{
CourseID = course.CourseID,
Title = course.Title,
Assigned = instructorCourses.Contains(course.CourseID)
});
}
}
public void UpdateInstructorCourses(string[] selectedCourses, InstructorWithCollection instructorToUpdate)
{
if (selectedCourses == null)
{
instructorToUpdate.Courses = new List <Course>();
return;
}
if (instructorToUpdate.Courses == null)
{
instructorToUpdate.Courses = new List <Course>();
}
var selectedCoursesHS = new HashSet <string>(selectedCourses);
var instructorCourses = new HashSet <int>
(instructorToUpdate.Courses.Select(c => c.CourseID));
foreach (var course in _courses)
{
if (selectedCoursesHS.Contains(course.CourseID.ToString()))
{
if (!instructorCourses.Contains(course.CourseID))
{
instructorToUpdate.Courses.Add(
new Course
{
CourseID = course.CourseID,
Title = course.Title,
Credits = course.Credits
});
}
}
else
{
if (instructorCourses.Contains(course.CourseID))
{
Course courseToRemove
= instructorToUpdate
.Courses
.SingleOrDefault(i => i.CourseID == course.CourseID);
instructorToUpdate.Courses.Remove(courseToRemove);
}
}
}
}