// Method to update AlumTechs
private void UpdateAlumTechs(int[] selectedTechs, Alum alumToUpdate)
{
if (selectedTechs == null)
{
var unknown = (from t in _context.Tech
where t.Name.Equals("(Unknown)")
select t.Id).ToArray();
selectedTechs = unknown;
}
var selectedTechsHS = new HashSet <int>(selectedTechs);
var alumTechs = new HashSet <int>
(alumToUpdate.AlumTech.Select(c => c.Tech.Id));
foreach (var tech in _context.Tech)
{
if (selectedTechsHS.Contains(tech.Id))
{
if (!alumTechs.Contains(tech.Id))
{
alumToUpdate.AlumTech.Add(new AlumTech {
AlumId = alumToUpdate.Id, TechId = tech.Id
});
}
}
else
{
if (alumTechs.Contains(tech.Id))
{
AlumTech techToRemove = alumToUpdate.AlumTech.SingleOrDefault(c => c.TechId == tech.Id);
_context.Remove(techToRemove);
}
}
}
}
public async Task <IActionResult> Create([Bind("Id,FirstName,LastName,CohortId,Address,Address2,City,State,ZipCode,Phone,Email,GitHub,LinkedIn,Slack")] Alum alum)
{
if (ModelState.IsValid)
{
_context.Add(alum);
await _context.SaveChangesAsync();
return(RedirectToAction(nameof(Index)));
}
ViewData["CohortId"] = new SelectList(_context.Cohort, "Id", alum.CohortId);
return(View(alum));
}
// Adding viewmodel to display multiple Tech checkboxes
private List <AssignedTechData> PopulateAlumTechData(Alum alum)
{
var allTechs = _context.Tech;
var alumTechs = new HashSet <int>(alum.AlumTech.Select(a => a.TechId));
var viewModel = new List <AssignedTechData>();
foreach (var tech in allTechs)
{
viewModel.Add(new AssignedTechData
{
TechId = tech.Id,
TechName = tech.Name,
Assigned = alumTechs.Contains(tech.Id)
});
}
return(viewModel);
}
public async Task <IActionResult> Edit(int id, int[] selectedTechs, [Bind("Id,FirstName,LastName,CohortId,Address,City,State,ZipCode,Phone,Email,GitHub,LinkedIn,Slack")] Alum alum)
{
if (id != alum.Id)
{
return(NotFound());
}
var alumToUpdate = await _context.Alum
.Include(a => a.Cohort)
.Include(a => a.AlumTech).ThenInclude(at => at.Tech)
.SingleOrDefaultAsync(m => m.Id == id);
List <string> cohortList = _context.Cohort.Select(c => c.Id).ToList();
if (await TryUpdateModelAsync <Alum>(
alumToUpdate,
"",
a => a.Id, a => a.FirstName, a => a.LastName, a => a.CohortId, a => a.Address, a => a.City, a => a.State, a => a.ZipCode, a => a.Phone, a => a.Email, a => a.GitHub, a => a.LinkedIn, a => a.Slack, a => a.AlumTech))
{
UpdateAlumTechs(selectedTechs, alumToUpdate);
try
{
await _context.SaveChangesAsync();
}
catch (DbUpdateException /* ex */)
{
//Log the error (uncomment ex variable name and write a log.)
ModelState.AddModelError("", "Unable to save changes. " +
"Try again, and if the problem persists, " +
"see your system administrator.");
}
return(RedirectToAction("Details", new { id }));
}
ViewData["CohortList"] = cohortList;
UpdateAlumTechs(selectedTechs, alumToUpdate);
PopulateAlumTechData(alumToUpdate);
return(View(alumToUpdate));
}