//If Modify Button was clicked on Form1
private void frmAddModify_Load(object sender, EventArgs e)
{
if (!isAdd) // Set up for Modify mode - use the Package passed from the last form to populate fields
{
// Update the title and description of the page
lblTitle.Text = "Package Manager - Edit Package";
lblDesc.Text = $"Edit any details and modify product list for the current package (ID #{currentPackage.PackageId}).";
using (travelexpertsDataContext db = new travelexpertsDataContext())
{
// Grab current package ID used to create this modify page
int packageId = currentPackage.PackageId;
// Use an in-depth query to grab the info needed for the product info data grid
dataGridView1.DataSource = TravelExpertsQueryManager.FindProdInfoByPackage(db, currentPackage.PackageId);
}
// Set up a snapshot of current associated package_product_suppliers entries
ppsSnapshot = TravelExpertsQueryManager.GetPackagesProductsSuppliersByPackageID(currentPackage.PackageId);
// handle nullable datetime
if (currentPackage.PkgStartDate == null)
{
EmptyDateTimePicker(pkgStartDateDateTimePicker);
}
if (currentPackage.PkgEndDate == null)
{
EmptyDateTimePicker(pkgEndDateDateTimePicker);
}
// Display current package information in details view
packageBindingSource.Add(currentPackage);
}
else // Set up for Add mode
{
// Update the title and description of the page
lblTitle.Text = "Package Manager - Add A New Package";
lblDesc.Text = "Add details and products for a new package.";
EmptyDateTimePicker(pkgStartDateDateTimePicker);
EmptyDateTimePicker(pkgEndDateDateTimePicker);
}
}
// Go back to last page without saving changes. This may involve some cleaning up, depending on the mode and if products were added [Eric]
private void btnCancel_Click(object sender, EventArgs e)
{
using (travelexpertsDataContext dbContext = new travelexpertsDataContext())
{
// First, we have to check to see if any products were added to the package before cancelling
if (didAddProducts) // this will be true if so - no need to spend time querying the db
{
// Get the current PPS entries in the database corresponsind to this package
List <Packages_Products_Supplier> ppsCurrent =
TravelExpertsQueryManager.GetPackagesProductsSuppliersByPackageID(currentPackage.PackageId);
// Next, we have to get the PPS entries to re-add (if they were deleted) and/or remove (if new ones were added)
// This is not a super efficient process, but packages shouldn't have enough products for it to make much difference
// First, get the ones to re-add
List <Packages_Products_Supplier> ppsToAdd = ppsSnapshot // Creating a list of Package_Product_Suppliers where...
.Where(ppsSnap => !ppsCurrent // ...for each snapshot entry, it is NOT the case that...
.Any(ppsCurr => ppsCurr.ProductSupplierId == ppsSnap.ProductSupplierId)) // ...any current entry has that snapshot entry's ProductSupplierID
.ToList();
// Next, the ones to remove
List <Packages_Products_Supplier> ppsToDelete = ppsCurrent // Creating a list of Package_Product_Suppliers where...
.Where(ppsCurr => !ppsSnapshot // ...for each current entry, it is NOT the case that...
.Any(ppsSnap => ppsCurr.ProductSupplierId == ppsSnap.ProductSupplierId)) // ...any snapshot entry has that current entry's ProductSupplierID
.ToList();
// Add the needed entries back
foreach (Packages_Products_Supplier ppsA in ppsToAdd)
{
// LINQ to SQL doesn't let you re-add old entity objects, so we need to create copies to add back in place
Packages_Products_Supplier clone = new Packages_Products_Supplier
{
PackageId = ppsA.PackageId,
ProductSupplierId = ppsA.ProductSupplierId
};
dbContext.Packages_Products_Suppliers.InsertOnSubmit(clone);
}
// Delete the entries to undo
foreach (Packages_Products_Supplier ppsD in ppsToDelete)
{
// Deleting only works on entities from the current context, so need to grab them
// I'm sure this could be done in the ones-to-remove LINQ query above, but I couldn't manage it
Packages_Products_Supplier deleteTarget = dbContext.Packages_Products_Suppliers // Search in the table...
.Single(pps => // ...for the one entry, with...
pps.ProductSupplierId == ppsD.ProductSupplierId && //...the matching ProductSupplierID...
pps.PackageId == ppsD.PackageId); //... and the matching PackageID
dbContext.Packages_Products_Suppliers.DeleteOnSubmit(deleteTarget);
}
// Save changes. Phew!
dbContext.SubmitChanges();
}
// One more step if in Add mode.
// A package was inserted into the database initially (to get the add products half to work).
// So, if cancelling, we want to delete it this created package.
if (isAdd)
{
// Delete package
Package packToDelete = dbContext.Packages
.Single(p => p.PackageId == currentPackage.PackageId);
dbContext.Packages.DeleteOnSubmit(packToDelete);
dbContext.SubmitChanges(); // submit to the database
}
}
// Exit the form
DialogResult = DialogResult.Cancel;
this.Close();
}