Insert Row At End Of Section Error - ios

Question

I'm trying to allow the user to insert rows at the end of sections but I'm getting an error. However everything seems correct so there must be something that I'm not seeing. Can someone point me in the right direction. Attached is my code, the error, and a screenshot of the table.
//
// Test.swift
// Table Views
//
// Created by Deion Long on 7/18/15.
// Copyright (c) 2015 Deion Long. All rights reserved.
//
import UIKit
var array = ["Section 1", "Section 2"]
extension UITableView {
func indexPathForView (view : UIView) -> NSIndexPath? {
let location = view.convertPoint(CGPointZero, toView:self)
return indexPathForRowAtPoint(location)
}
}
class Test: UIViewController, UITableViewDelegate, UITableViewDataSource {
var things:NSMutableArray = ["hi", "bye", "kie"]
#IBAction func editBtnClicked(sender: AnyObject) {
//When not in editing mode already set editing to true
if(table.editing == false){
self.editing = true
println("hi")
table.setEditing(true, animated: true)
}else{
self.editing = false
table.setEditing(false, animated: true)
}
}
#IBOutlet weak var table: UITableView!
#IBAction func doneButton(sender: AnyObject) {
table.reloadData()
}
override func viewDidLoad() {
super.viewDidLoad()
table.allowsSelectionDuringEditing = true
}
func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return array.count // This was put in mainly for my own unit testing
}
func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
return array[section]
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
var addRow = self.editing ? 1 : 0
println(addRow)
return addRow + things.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("textInputCell3") as! DetailCell
if (indexPath.row >= things.count && self.editing) {
cell.configure(text: "Add Row", placeholder: "Enter")
} else{
cell.configure(text: things.objectAtIndex(indexPath.row) as! String, placeholder: "Enter")
}
return cell
}
override func setEditing(editing: Bool, animated: Bool) {
super.setEditing(editing, animated: animated)
self.table.setEditing(editing, animated: animated)
if(editing){
table.beginUpdates()
for var i = 0; i < self.table.numberOfSections(); i++
{
var lastRow = table.numberOfRowsInSection(i)
var lastIndex = NSIndexPath(forRow: lastRow, inSection: i)
table.insertRowsAtIndexPaths([lastIndex], withRowAnimation: UITableViewRowAnimation.Automatic)
}
table.endUpdates()
}
}
func tableView(tableView: UITableView, editingStyleForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCellEditingStyle {
if(indexPath.row >= things.count){
return UITableViewCellEditingStyle.Insert
}else{
return UITableViewCellEditingStyle.Delete
}
}
func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if (editingStyle == UITableViewCellEditingStyle.Delete) {
things.removeObject(indexPath.row)
table.deleteRowsAtIndexPaths([indexPath], withRowAnimation: .Fade)
}
else if (editingStyle == UITableViewCellEditingStyle.Insert) {
things.insertObject("123", atIndex: self.things.count)
table.insertRowsAtIndexPaths([indexPath], withRowAnimation: .Automatic)
}
}
}
ERROR: Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 1. The number of rows contained in an existing section after the update (5) must be equal to the number of rows contained in that section before the update (4), plus or minus the number of rows inserted or deleted from that section (0 inserted, 0 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'

Answer 1

The error message says it all. You mustn't insert the row until you've updated the model data to have the extra row. You may be confusing yourself with your sections here; practice with just one section first. Your model does not seem very well designed to distinguish the two sections.

Answer 2

In the setEditing: you are inserting rows inside the beginUpdates and endUpdates function of UITableView
table.beginUpdates()
for var i = 0; i < self.table.numberOfSections(); i++ {
var lastRow = table.numberOfRowsInSection(i)
var lastIndex = NSIndexPath(forRow: lastRow, inSection: i)
table.insertRowsAtIndexPaths([lastIndex], withRowAnimation: UITableViewRowAnimation.Automatic)
}
table.endUpdates()
When you are inserting rows make sure that you are updating your model object things. If you just want to reload the data of the cell use
table.reloadRowsAtIndexPaths([lastIndex], withRowAnimation: UITableViewRowAnimation.Automatic)