// To protect from overposting attacks, enable the specific properties you want to bind to, for
// more details, see https://aka.ms/RazorPagesCRUD.
public async Task <IActionResult> OnPostAsync()
{
if (!ModelState.IsValid)
{
return(Page());
}
_context.Attach(Product).State = EntityState.Modified;
try
{
await _context.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!ProductExists(Product.Id))
{
return(NotFound());
}
else
{
throw;
}
}
return(RedirectToPage("./Index"));
}
public void Update(Product entity)
{
List <int> newCategories = entity.Categories.Select(x => x.CategoryId).ToList();
if (_entities.Any(p => p.Code == entity.Code && p.Id != entity.Id))
{
throw new InvalidOperationException("Product with the same code already exists.");
}
foreach (var prodToCat in entity.Categories)
{
prodToCat.ProductId = entity.Id;
}
if (_context.Entry(entity).State == EntityState.Detached)
{
_context.Attach(entity);
}
_context.Entry(entity).State = EntityState.Modified;
var existingCategories = _context.ProductsToCategories.Where(c => c.ProductId == entity.Id);
foreach (var protToCat in entity.Categories)
{
//check for new assigned categories
if (!existingCategories.Any(e => e.CategoryId == protToCat.CategoryId))
{
_context.Entry(protToCat).State = EntityState.Added;
}
}
foreach (var protToCat in existingCategories)
{
//check for deleted categories connection
if (!newCategories.Any(e => e == protToCat.CategoryId))
{
_context.Entry(protToCat).State = EntityState.Deleted;
}
}
}
