Cell formats incorrectly when inserting row - ios

Question

I'm having a very interesting event happening when I load a new item into Core data / UITableView.
One thing to note is that before I didn't have Sections implemented and I never had anything like this happening. But after I added in sections, it randomly started.
It only happens right when I add in (insert) a new entry into Core data / UITableView. If I go back to the previous View Controller and then go back to the table, it will automatically fix it's self.
Here is a picture of what it is currently doing when I add a new row.
As you can see on the left side, a few of the labels, Image, and Button, are scattered, and on the right side things are all where they belong.
Everything has been fully constrained and works on all the various phone sizes. But like I said, it all started happening after I added in the section feature.
I'm assuming that only the code for the TableViewController is needed, so please see below.
import UIKit
import CoreData
class ListItemsTableViewController: UITableViewController, NSFetchedResultsControllerDelegate {
let moc = (UIApplication.sharedApplication().delegate as! AppDelegate).managedObjectContext
var frc: NSFetchedResultsController = NSFetchedResultsController()
var list: Lists?
var catalog: Catalog?
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.reloadData()
self.title = list?.name
frc = getFCR()
frc.delegate = self
do {
try frc.performFetch()
} catch {
print("Failed to perform inital fetch")
}
// Uncomment the following line to preserve selection between presentations
//self.clearsSelectionOnViewWillAppear = true
// Uncomment the following line to display an Edit button in the navigation bar for this view controller.
// self.navigationItem.rightBarButtonItem = self.editButtonItem()
}
override func viewWillAppear(animated: Bool) {
let imageView = UIImageView(image: UIImage(named: "TableBackground"))
imageView.contentMode = .ScaleAspectFill
self.tableView.backgroundView = imageView
self.tableView.tableFooterView = UIView(frame: CGRectZero)
self.tableView.reloadData()
}
override func viewDidAppear(animated: Bool) {
frc = getFCR()
frc.delegate = self
do {
try frc.performFetch()
} catch {
fatalError("Failed to perform inital fetch")
}
self.tableView.reloadData()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
if let sections = frc.sections {
return sections.count
}
return 0
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if let sections = frc.sections {
let currentSection = sections[section]
return currentSection.numberOfObjects
}
return 0
}
override func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
if let sections = frc.sections {
let currentSection = sections[section]
return currentSection.name
}
return nil
}
override func tableView(tableView: UITableView, willDisplayHeaderView view: UIView, forSection section: Int) {
let header: UITableViewHeaderFooterView = view as! UITableViewHeaderFooterView
header.contentView.backgroundColor = UIColor(red: 84/255, green: 200/255, blue: 214/255, alpha: 0.5)
header.textLabel!.textColor = UIColor.whiteColor()
//header.alpha = 0.5 //make the header transparent
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("listContentCell", forIndexPath: indexPath) as! ListItemsTableViewCell
let item = frc.objectAtIndexPath(indexPath) as! Items
cell.separatorInset = UIEdgeInsets(top: 0, left: 78, bottom: 0, right: 0)
cell.itemName.text = item.name
cell.itemSection.text = item.section
cell.itemQty.text = "Qty: \(item.qty!)"
cell.itemSize.text = item.size
cell.itemPrice.text = floatToCurrency(Float(item.cost!))
cell.itemImage.image = UIImage(data: item.image!)
cell.itemID.text = String(item.id!)
return cell
}
override func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {
cell.backgroundColor = UIColor.clearColor()
}
override func tableView(tableView: UITableView, editActionsForRowAtIndexPath indexPath: NSIndexPath) -> [UITableViewRowAction]? {
let delete = UITableViewRowAction(style: .Destructive, title: "Delete") { (action, indexPath) in
let request = self.fetchRequest()
var fetchResults = [AnyObject]()
do {
fetchResults = try self.moc.executeFetchRequest(request)
} catch {
fatalError("Fetching Data to Delete Failed")
}
self.moc.deleteObject(fetchResults[indexPath.row] as! NSManagedObject)
fetchResults.removeAtIndex(indexPath.row)
do {
try self.moc.save()
} catch {
fatalError("Failed to Save after Delete")
}
}
let edit = UITableViewRowAction(style: .Normal, title: "Edit") { (action, indexPath) in
// Code to come
}
let qty = UITableViewRowAction(style: .Normal, title: "Qty") { (action, indexPath) in
// Code to come
}
edit.backgroundColor = UIColor.init(red: 84/255, green: 200/255, blue: 214/255, alpha: 1)
return [delete, edit, qty]
}
func controllerWillChangeContent(controller: NSFetchedResultsController) {
tableView.beginUpdates()
}
func controllerDidChangeContent(controller: NSFetchedResultsController) {
tableView.endUpdates()
}
func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
switch type {
case NSFetchedResultsChangeType.Delete:
self.tableView.deleteSections(NSIndexSet(index: sectionIndex), withRowAnimation: UITableViewRowAnimation.Automatic)
case NSFetchedResultsChangeType.Insert:
self.tableView.insertSections(NSIndexSet(index: sectionIndex), withRowAnimation: UITableViewRowAnimation.Automatic)
/*case NSFetchedResultsChangeType.Update:
tableView.reloadSections(NSIndexSet(index: sectionIndex), withRowAnimation: UITableViewRowAnimation.Automatic)*/
default:
print("didChangeSection Default was accessed")
break
}
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
switch type {
case NSFetchedResultsChangeType.Delete:
self.tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
case NSFetchedResultsChangeType.Insert:
self.tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
self.tableView.reloadData()
case NSFetchedResultsChangeType.Update:
let cell = self.tableView.cellForRowAtIndexPath(indexPath!) as! ListItemsTableViewCell
let item = self.frc.objectAtIndexPath(indexPath!) as! Items
cell.itemName.text = item.name
cell.itemSection.text = item.section
cell.itemQty.text = "Qty: \(item.qty!)"
cell.itemSize.text = item.size
cell.itemPrice.text = floatToCurrency(Float(item.cost!))
cell.itemImage.image = UIImage(data: item.image!)
cell.itemID.text = String(item.id!)
case NSFetchedResultsChangeType.Move:
self.tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
self.tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
}
}
func fetchRequest() -> NSFetchRequest {
let fetchRequest = NSFetchRequest(entityName: "Items")
let sortDesc1 = NSSortDescriptor(key: "section", ascending: true)
let sortDesc2 = NSSortDescriptor(key: "isChecked", ascending: true)
let sortDesc3 = NSSortDescriptor(key: "name", ascending: true)
fetchRequest.sortDescriptors = [sortDesc1, sortDesc2, sortDesc3]
return fetchRequest
}
func getFCR() -> NSFetchedResultsController {
frc = NSFetchedResultsController(fetchRequest: fetchRequest(), managedObjectContext: moc, sectionNameKeyPath: "section" , cacheName: nil)
return frc
}
func getCatalog(id: NSNumber) -> Catalog {
var cat: Catalog?
let fetchReq = NSFetchRequest(entityName: "Catalog")
let pred = NSPredicate(format: "%K == %#", "id", id)
fetchReq.predicate = pred
do {
let check = try moc.executeFetchRequest(fetchReq)
cat = (check.first as! Catalog)
} catch {
fatalError("Failed fetching Catalog Entry matching Item")
}
return cat!
}
func floatToCurrency(flt: Float) -> String {
let formatter = NSNumberFormatter()
formatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
return String(formatter.stringFromNumber(flt)!)
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
var id: NSNumber
if (segue.identifier == "listItemView") {
let cell = sender as! UITableViewCell
let indexPath = self.tableView.indexPathForCell(cell)
let itemCont: ViewItemViewController = segue.destinationViewController as! ViewItemViewController
let item: Items = self.frc.objectAtIndexPath(indexPath!) as! Items
itemCont.item = item
id = item.id!
itemCont.catalog = getCatalog(id)
} else if (segue.identifier == "listItemViewEdit") {
let cell = sender as! UITableViewCell
let indexPath = self.tableView.indexPathForCell(cell)
let itemCont: AddItemListViewController = segue.destinationViewController as! AddItemListViewController
let item: Items = self.frc.objectAtIndexPath(indexPath!) as! Items
itemCont.item = item
id = item.id!
itemCont.catalog = getCatalog(id)
itemCont.list = list
}
}
}
Like I said previously, this wasn't a problem till I added in Sections. But when I click the the back button (< Lists) and then go back to this view, it will automatically correct itself to what is shown on the right.
Also, it doesn't do it every time. Sometimes it'll just do it the first time I add an item when entering the TableView. And it also doesn't seem to do it to items that get added outside the view. i.e. rows that exist well below the viewable area of the screen.
Editing and deleting doesn't seem to cause this problem either, just adding new items.
If I were to guess, somehow the UIImage is getting a small or zero size and it's breaking everything else. But the Size Label and Price Label ($0.00) are directly linked the Qty Label which never seems to move.
So it seems like if the UIImage were messing things up, it would also mess up the Qty Label too.
It's not an app breaker, but it looks really crapy and dumb that it has to be reloaded by exiting the ViewController then going back in. (also, I've tried putting self.tableView.reloaddata() in multiple different places but none seem to fix the problem.)
EDIT:
Removed all constraints and remade them again. It only made things worse, see image below.
EDIT 2:
Added constraints image
EDIT 3:
I'm guessing at this point, the post is dead and I'll have to go elsewhere to find answers to what is going on, but I was able to narrow it down to when the error specifically comes into play. When looking at one of my older backups of my app, where I was not having this issue, I slowly edited it till I started getting the problem. And my error comes in from the didChangeObject function. Before, I had code like this
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
if (type == .delete) {
self.tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
}
}
And my cell would format correctly, but as soon as I updated it to be this
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
switch type {
case NSFetchedResultsChangeType.Delete:
self.tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
case NSFetchedResultsChangeType.Insert:
self.tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
case NSFetchedResultsChangeType.Update:
let cell = self.tableView.cellForRowAtIndexPath(indexPath!) as! ListItemsTableViewCell
let item = self.frc.objectAtIndexPath(indexPath!) as! Items
cell.itemName.text = item.name
cell.itemSection.text = item.section
cell.itemQty.text = "Qty: \(item.qty!)"
cell.itemSize.text = item.size
cell.itemPrice.text = floatToCurrency(Float(item.cost!))
cell.itemImage.image = UIImage(data: item.image!)
cell.itemID.text = String(item.id!)
case NSFetchedResultsChangeType.Move:
self.tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
self.tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: UITableViewRowAnimation.Automatic)
}
}
My cell would no longer format correctly. After further testing, I found that the move type also created the same formatting error, so my problem is specifically caused by self.tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: UITableViewRowAnimation.Automatic). The main reason I switched from what I had to to the longer statement is when I added in sections, I would get an error saying that the sections before and after didn't match (specifically when a entry was modified to where it would switch to a new section), and from everything I can find online the longer way is the correct way to do it... but for some reason it causes formatting errors on my application. Could be my code (very likely since I'm new at all of this) or could be an bug with Xcode.
I don't plan to give up on this, but I can only bang my head against the wall for so long before I start to loose my mind, so I'll probably take a break for a while.
I'd definitely appreciate any suggestions if you have any though. Hope this post somehow hopes someone else.

Answer 1

What i can guess is that there might be some problem with your viewDidLoad() and viewWillAppear() functions , you can learn about the sequence they get executed like viewDidLoad() is called only one time when view appears for first time and than the work is upto viewWillAppear() , i guess that's where you have image code ,that corrects the things once you come to this view second times . And i have little questions like you are using storyboard for size ,price and quantity labels and your image view right or not ?
And try to use some breakpoints for knowing the difference that how your code gets correct view second point . Like you can put breakpoints in important functions like viewDidload(), viewDidAppear() and viewWillAppear.
The constraints in this image work for me .
Here is the output.
and using print(cell.itemImage.frame.size.width) in cellForRowAtIndexPath gave me the width of 61 and i got the same height 61 as well .
You can show me the snapshot of constraints like i have shown and i can tell you what's wrong .

Answer 2

In the end, it ended up being that I needed to turn off Size Classes. I don't fully understand why this was a problem, but it has fixed everything.