Reuse Storyboard viewcontrollers - ios

Question

I am rebuilding an application where I need to show a list of items. This list is retrieved using an API or retrieved from Core Data and shown in a UITableViewController. The problem I am having is that there are already seven different lists where there are small differences. Mostly of them are just different items, but also a search bar included in one list and previously stated one list will not load using an API, but from Core Data.
In my Storyboard I have added a UITableViewController with the class ItemsTableViewController which has a designed UITableViewCell. I have added an identifier to this cell so I can reuse it inside this view controller. There is a segue to this view controller from the home screen.
The idea was to create one parent object (ItemsTableViewController) and add multiple child objects (SavedItemsTableViewController, LocalItemsTableViewController, etc.) which will all use the shared logic of the parent with only some small changes (API and some custom things).
What I currently have is working, but without the child objects:
- (void)offlineButtonPressed {
[self performSegueWithIdentifier:#"openItemsTableViewController" sender:#(ItemListOffline)];
//[[self navigationController] pushViewController:[[OfflineItemsTableViewController alloc] init] animated:YES];
}
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
if ([[segue identifier] isEqualToString:#"openItemsTableViewController"]) {
switch((ItemList)[sender unsignedIntegerValue]) {
case ItemListOffline: { [(ItemsTableViewController *)[segue destinationViewController] retrieveOfflineDocuments]; break; }
case ItemListSearch: {
[(ItemsTableViewController *)[segue destinationViewController] retrieveDocumentsWithQuery:#""];
[(ItemsTableViewController *)[segue destinationViewController] addSearchBar];
break;
}
// Loop through all the list...
default: { NSAssert(NO, #"Unhandled type of document list."); break; }
}
}
}
So the application is calling just a function of the parent object which handles the request. But as you probably can feel, the object will be less maintainable. In comments I pushed the child view controller, but since it doesn't include the storyboard view, I need to recreate the cell from scratch, which doesn't feel good. Plus since the reuse identifier, it is not working since it is unable to dequeue a cell with the identifier set in the tableView:cellForRowAtIndexPath: method.
Now I am wondering what would be the best practice for this? It seems I can't use the save UITableViewController from the storyboard for multiple child classes, can I? But creating seven (and probably a even more in the future) controllers in the storyboard where I need to copy the cells to each controller and just give them different classes doesn't seem the way to do it. And add a method to the parent where the list would be retrieved differently and changing some stuff like adding a search bar is working, but also not the nicest way it seems.
Update: The logic in the ItemsTableViewController is pretty simple. In the delegate and datasource I handle the documents almost the same. The method that does the retrieving per list type is something like:
- (void)retrieveOfflineItems {
[self startLoading];
[[APIManager instance] getOfflineItems:^(NSArray<ItemList *> *list, NSError *error) {
[self setDocuments:list];
[[self tableView] reloadData];
}];
}
But there are more things, like the search has to add a search bar (once the view is loaded). So it needs to call multiple methods when performing the segue.

Answer 1

You can have a single UITableViewController, which includes all of your possible table cells, and as part of the prepareForSegue call, you should set an type identifier for the controller and the data - no matter where the data came from.
Within the UITableViewController class, you can hide / display the features that you need for this data type - such as the search bar, and in the tableView methods, choose which data source you need.
This way, the one UITableViewController class that you need to maintain is a little more complex than one dedicated class, but a lot more maintainable than 7 or more!
Assuming you have set up a variable dataType to identify the type of data you need, you could have something like this for the numberOfRowsInSection, and then similar for the other tableView methods
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
switch self.dataType {
case dataType.MyFirstDataType:
return myFirstDataTypeArray.count
case dataType.MySecondDataType:
return mySecondDataTypeArray.count
case dataType.TheCoreDataType:
return myCoreDataArray.count
default:
break
}
}

Answer 2

Create a parent UITableViewController with all subviews and cells including searchController. Initialize it and add/remove views and cells based on conditions