public async Task <IActionResult> Edit(int?id, byte[] rowVersion)
{
string[] fieldsToBind = new string[] { "Name", "RowVersion" };
if (id == null)
{
return(NotFound());
}
var categoryToUpdate = await _context.Category.FindAsync(id);
if (categoryToUpdate == null)
{
Category deletedCategory = new Category();
await TryUpdateModelAsync(deletedCategory, "", s => s.ID, s => s.Name, s => s.RowVersion);
ModelState.AddModelError(string.Empty, "Unable to save your changes because the " +
"category has been deleted by another user.");
return(View(deletedCategory));
}
if (await TryUpdateModelAsync(categoryToUpdate, "", s => s.ID, s => s.Name, s => s.RowVersion))
{
try
{
_context.Entry(categoryToUpdate).OriginalValues["RowVersion"] = rowVersion;
await _context.SaveChangesAsync();
return(RedirectToAction("Index"));
}
catch (DbUpdateConcurrencyException ex)
{
var exEntry = ex.Entries.Single();
var currentUIValues = (Category)exEntry.Entity;
var databaseCategory = exEntry.GetDatabaseValues();
if (databaseCategory == null)
{
ModelState.AddModelError(string.Empty, "Unable to save your changes because " +
"the category has been deleted by another user.");
}
else
{
var databaseCategoryValues = (Category)databaseCategory.ToObject();
if (databaseCategoryValues.Name != currentUIValues.Name)
{
ModelState.AddModelError("Name", "Current value in database: " + databaseCategoryValues.Name);
}
ModelState.AddModelError(string.Empty, "The record has been modified by " +
"another user after you loaded the screen. Your changes have not yet been saved. " +
"The new values in the database are shown below. If you want to overwrite these values" +
" with your changes then click save otherwise go back to the categories page.");
categoryToUpdate.RowVersion = (byte[])databaseCategoryValues.RowVersion;
ModelState.Remove("RowVersion"); //This is must because ModelState has the old RowVersion value. In the Razor Page the ModelState value for a field takes precedence over the model property values when bot are present
}
}
}
return(View(categoryToUpdate));
}
public async Task <IActionResult> Upload(IFormFile[] files)
{
bool allValid = true;
string inValidFiles = "";
//check the user has entered a file
if (files.Length != 0)
{
//if the user has entered less than 10 files
if (files.Length <= 10)
{
foreach (var file in files)
{
if (!ValidateFile(file))
{
allValid = false;
inValidFiles += ", " + Path.GetFileName(file.FileName);
}
}
//if they are valid then try to save them to disk
if (allValid)
{
foreach (var file in files)
{
try
{
SaveFileToDiskAsync(file);
}
catch (Exception)
{
ModelState.AddModelError("FileName", "Sorry an error occurred saving the file to disk, please try again");
}
}
}
//else add an error listing out the invalid files
else
{
ModelState.AddModelError("FileName", "All files must be gif, png, jpeg or jpg and less than 2MB in size.The following files" + inValidFiles + " are not valid");
}
}
//the user has entered more than 10 files
else
{
ModelState.AddModelError("FileName", "Please only upload up to ten files at a time");
}
}
else
{
//if the user has not entered a file return an error message
ModelState.AddModelError("FileName", "Please choose a file");
}
if (ModelState.IsValid)
{
bool duplicates = false;
bool otherDbError = false;
string duplicateFiles = "";
foreach (var file in files)
{
//try and save each file
var productToAdd = new ProductImage {
FileName = Path.GetFileName(file.FileName)
};
try
{
_context.Add(productToAdd);
await _context.SaveChangesAsync();
}
//if there is an exception check if it is caused by duplicate file
catch (DbUpdateException ex)
{
SqlException innerException = ex.InnerException as SqlException;
if (innerException != null && innerException.Number == 2601)
{
duplicateFiles += "," + Path.GetFileName(file.FileName);
duplicates = true;
_context.Entry(productToAdd).State = EntityState.Detached;
}
else
{
otherDbError = true;
}
}
}
//add a list of duplicate files to the error message
if (duplicates)
{
ModelState.AddModelError("FileName", "All files uploaded except the files" + duplicateFiles
+ ", which already exist in the system ." + " Please delete them and try again if you wish to re-add them");
return(View());
}
else if (otherDbError)
{
ModelState.AddModelError("FileName", "Sorry an error has occurred saving to the database, please try again");
return(View());
}
return(RedirectToAction(nameof(Index)));
}
return(View());
}
