How can I add/remove cells in a table view more elegantly?

Question

I think this is probably an X Y problem, so I\'ll give some background info first.

I am building an app that can show a \"form\". The user can fill in the form with

Answer 1

Because you don't have any data source. Also see logically: suppose you add a new row with insertRowsAtIndexPaths . So now you have 2 rows. However your numberOfRowsInSection always returning 1. so it will crash and vice versa for delete. Table view are supposed to work with a collection (NSArray, NSDictionary, NSSet etc.). For your help:

Already they have nade a form as yours

obj-c easy to understand how table view with data source work

Adding, Updating, Deleting and Moving records using Swift.

Answer 2

I found a solution!

I basically keep an array of an array of cells for the table view to display:

var cells: [[UITableViewCell]] = [[], [], []] // I have 3 sections, so 3 empty arrays

And then I added these data source methods:

override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
    return cells.count
}

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return cells[section].count
}

override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    return cells[indexPath.section][indexPath.row]
}

Now, I can add and remove cells super easily:

func addCellToSection(section: Int, index: Int, cell: UITableViewCell) {
    cells[section].insert(cell, atIndex: index)
    tableView.insertRowsAtIndexPaths([NSIndexPath(forRow: index, inSection: section)], withRowAnimation: .Left)
}

func removeCellFromSection(section: Int, index: Int) {
    cells[section].removeAtIndex(index)
    tableView.deleteRowsAtIndexPaths([NSIndexPath(forRow: index, inSection: section)], withRowAnimation: .Left)
}

With just two lines, I can add/remove cells with animation!

Answer 3

You may use a TableView to create the form but you must design an appropriate dataSource to keep track of these data. Now the dataSource method must be modified to

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return yourDataSourceForSection.count
}

You may edit this dataSource when a delete operation is performed as follows

override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
    if editingStyle == .Delete {
        //Delete the row from the data source to ensure consistency
        self.array.removeAtIndex(indexPath.row)
        tableView.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
    }
}

You may use a model class as the dataSource.

class NewCustomOperation: NSObject {
   var name: String?
   var rejectFloatingPoints: Bool?
   var inputs: AvailableInputs?
   var results: Results?
}

class AvailableInputs: NSObject {
   var name: [String]?
   var description: [String]?
}

class Results: NSObject {
   var name: [String]?
   var formula: [String]?
}