This question already has answers here:
ActionSheet not working iPad
(8 answers)
Closed 3 years ago.
Basically I have an app that takes in user input (in 5 textfields in an alertcontroller) that are all concatenated in to a string to be in a form that looks like it is a row in a csv file and stored to coredata as an entity. This entity will then be displayed in a tableview. I would like to be able to export the csv file to email it elsewhere. All this will be done in the iOS device itself.
I have referred to the code in (How to Export Core Data to CSV in Swift 3?) to do the code for the exporting of coredata entries. My app is able to be built successfully. Adding and removing items from the tableview all work fine. It is only until I click on my export button that the app crashes.
class ViewController: UITableViewController, NSFetchedResultsControllerDelegate {
let cellId = "cellId"
fileprivate lazy var fetchedResultsController: NSFetchedResultsController<AlarmItem> = {
//create fetch request
let fetchRequest: NSFetchRequest<AlarmItem> = AlarmItem.fetchRequest()
//configure fetch request
fetchRequest.sortDescriptors = [NSSortDescriptor(key: "alarmAttributes", ascending: true)]
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: context, sectionNameKeyPath: nil, cacheName: nil)
let managedObjectContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
fetchedResultsController.delegate = self
return fetchedResultsController
}()
func controllerWillChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
tableView.beginUpdates()
}
func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
tableView.endUpdates()
}
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
switch(type) {
case .insert:
if let indexPath = newIndexPath {
tableView.insertRows(at: [indexPath], with: .fade)
}
break;
case .delete:
if let indexPath = indexPath {
tableView.deleteRows(at: [indexPath], with: .fade)
}
break;
case .update:
if let indexPath = indexPath, let cell = tableView.cellForRow(at: indexPath) {
configureCell(cell, at: indexPath)
}
break;
case .move:
if let indexPath = indexPath {
tableView.deleteRows(at: [indexPath], with: .fade)
}
if let newIndexPath = newIndexPath {
tableView.insertRows(at: [newIndexPath], with: .fade)
}
break;
#unknown default:
print("Something odd is happening")
}
}
override func viewDidLoad() {
super.viewDidLoad()
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
do {
try fetchedResultsController.performFetch()
} catch let err as NSError {
print("Failed to fetch items", err)
}
}
#objc func addAlarmItem(_ sender: AnyObject) {
let alertController = UIAlertController(title: "Add New Item", message: "Please fill in the blanks", preferredStyle: .alert)
let saveAction = UIAlertAction(title: "Save", style: .default) { [unowned self] action in
//combined string of attributes
let myStrings: [String] = alertController.textFields!.compactMap { $0.text }
let myText = myStrings.joined(separator: ", ")
self.save(myText)
self.tableView.reloadData()
}
let cancelAction = UIAlertAction(title: "Cancel", style: .destructive, handler: nil)
alertController.addTextField { (textField) in
textField.placeholder = "Enter Name of Engineer"
}
alertController.addTextField { (textField) in
textField.placeholder = "Enter Date of Alarm in DD/MM/YYYY"
}
alertController.addTextField { (textField) in
textField.placeholder = "Enter Time of Alarm in 24h (eg: 2300)"
}
alertController.addTextField { (textField) in
textField.placeholder = "Please indicate True/False (type True or False)"
}
alertController.addTextField { (textField) in
textField.placeholder = "Insert comments (if any), or NIL"
}
func save(_ itemName: String) {
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return }
let managedContext = appDelegate.persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "AlarmItem", in: managedContext)!
let item = NSManagedObject(entity: entity, insertInto: managedContext)
item.setValue(itemName, forKey: "alarmAttributes")
do {
try managedContext.save()
tableView.reloadData()
} catch let err as NSError {
print("Failed to save an item", err)
}
}
#objc func exportCSV(_ sender: AnyObject) {
exportDatabase()
}
func exportDatabase() {
let exportString = createExportString()
saveAndExport(exportString: exportString)
}
func saveAndExport(exportString: String) {
let exportFilePath = NSTemporaryDirectory() + "itemlist.csv"
let exportFileUrl = NSURL(fileURLWithPath: exportFilePath)
FileManager.default.createFile(atPath: exportFilePath, contents: NSData() as Data, attributes: nil)
var fileHandle: FileHandle? = nil
do {
fileHandle = try FileHandle(forUpdating: exportFileUrl as URL)
} catch {
print("filehandle has error")
}
if fileHandle != nil {
fileHandle!.seekToEndOfFile()
let csvData = exportString.data(using: String.Encoding.utf8, allowLossyConversion: false)
fileHandle!.write(csvData!)
fileHandle!.closeFile()
let firstActivityItem = NSURL(fileURLWithPath: exportFilePath)
let activityViewController : UIActivityViewController = UIActivityViewController(activityItems: [firstActivityItem], applicationActivities: nil)
activityViewController.excludedActivityTypes = [
UIActivity.ActivityType.assignToContact,
UIActivity.ActivityType.saveToCameraRoll,
UIActivity.ActivityType.postToFlickr,
UIActivity.ActivityType.postToVimeo,
UIActivity.ActivityType.postToTencentWeibo
]
self.present(activityViewController, animated: true, completion: nil)
}
}
func createExportString() -> String {
var alarmAttributes: String?
var export: String = NSLocalizedString("Engineer Name,Date of Alarm,Time of Alarm,True or False,Engineer Comments \n", comment: "")
for (index, AlarmItem) in fetchedStatsArray.enumerated() {
if index <= fetchedStatsArray.count - 1 {
alarmAttributes = AlarmItem.value(forKey: "alarmAttributes") as! String?
let alarmAttributeStrings = alarmAttributes
export += "\(alarmAttributeStrings ?? "0") \n"
}
}
print("the app will now print: \(export) ")
return export
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
let sectionInfo = fetchedResultsController.sections![section]
return sectionInfo.numberOfObjects
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath)
let alarmItem = fetchedResultsController.object(at: indexPath) as NSManagedObject
cell.textLabel?.text = alarmItem.value(forKeyPath: "alarmAttributes") as? String
return cell
}
func tableView(_ tableView: UITableView!, canEditRowAtIndexPath indexPath: NSIndexPath!) -> Bool {
return true
}
overr ide func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
guard editingStyle == .delete else { return }
//fetch
let toBeDeleted = fetchedResultsController.object(at: indexPath)
//delete
fetchedResultsController.managedObjectContext.delete(toBeDeleted)
do {
try fetchedResultsController.managedObjectContext.save()
} catch let err as NSError {
print("failed to save item", err)
}
}
func tableView(_tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "AlarmItem", for: indexPath)
configureCell(cell, at: indexPath)
return cell
}
func configureCell(_ cell: UITableViewCell, at indexPath: IndexPath) {
let alarmItem = fetchedResultsController.object(at: indexPath)
//configure cell
cell.textLabel?.text = alarmItem.value(forKeyPath: "alarmAttributes") as? String
}
}
It results in a "Thread 1: signal SIGABRT" error but I cannot find any typos in my code.
Here's the first call throw stack:
The full error code:
2019-06-26 10:04:33.843955+0800 TrueFalseAlarmV3[913:13287] libMobileGestalt MobileGestalt.c:890: MGIsDeviceOneOfType is not supported on this platform.
the app will now print: Engineer Name,Date of Alarm,Time of Alarm,True or False,Engineer Comments
2019-06-26 10:31:56.087370+0800 TrueFalseAlarmV3[913:13287] [MC] System group container for systemgroup.com.apple.configurationprofiles path is /Users/danialaqil/Library/Developer/CoreSimulator/Devices/BF0A3A59-A660-4F1D-B0FE-F0D226479D8D/data/Containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles
2019-06-26 10:31:56.087928+0800 TrueFalseAlarmV3[913:13287] [MC] Reading from private effective user settings.
2019-06-26 10:31:56.088526+0800 TrueFalseAlarmV3[913:18176] [MC] Filtering mail sheet accounts for bundle ID: imdadsl.TrueFalseAlarmV3, source account management: 1
2019-06-26 10:31:56.100398+0800 TrueFalseAlarmV3[913:18176] [MC] Filtering mail sheet accounts for bundle ID: imdadsl.TrueFalseAlarmV3, source account management: 2
2019-06-26 10:31:56.445312+0800 TrueFalseAlarmV3[913:13287] *** Terminating app due to uncaught exception 'NSGenericException', reason: 'Your application has presented a UIActivityViewController (). In its current trait environment, the modalPresentationStyle of a UIActivityViewController with this style is UIModalPresentationPopover. You must provide location information for this popover through the view controller's popoverPresentationController. You must provide either a sourceView and sourceRect or a barButtonItem. If this information is not known when you present the view controller, you may provide it in the UIPopoverPresentationControllerDelegate method -prepareForPopoverPresentation.'
*** First throw call stack:
(
the throw call stack is in the image above
On iPad, UIActivityViewController needs to be presented in a popover or the app will crash, see this answer for details.
Related
Sorry guys if there's already a thread about it but been stuck with it for a while.
I'm kinda new to CoreData(knows only how to persist and fetch items only) and I'm trying to do a little query in my app which will load only the ones with the isDone attribute = to "True".
the thing is I don't know how to use NSFetchRequest & NSPredicate so im kinda stuck, hope you guys can help me out with some tips <3, Here's my code:
import Foundation
import CoreData
import UIKit
import SwipeCellKit
class TasksManViewController: UITableViewController, SwipeTableViewCellDelegate {
#IBOutlet weak var Sege: UISegmentedControl!
let isSwipeRightEnabled = true
var tasksArray = [Task](){
didSet {
// because we perform this operation on the main thread, it is safe
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
}
var doneTasksArr = [Task]() // an array of what to disply.
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
override func viewDidLoad() {
}
override func viewWillAppear(_ animated: Bool) {
loadTasks()
}
// MARK: - DataSource + Delegate Methods:
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return tasksArray.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "taskCellRow") as! SwipeTableViewCell
cell.delegate = self
cell.textLabel?.text = tasksArray[indexPath.row].title
return cell
}
func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath, for orientation: SwipeActionsOrientation) -> [SwipeAction]? {
if orientation == .left {
guard isSwipeRightEnabled else { return nil }
let doneAction = SwipeAction(style: .destructive, title: "Done") { (action, indexPath) in
//STEP1: Append the task to the doneTasksArr:
self.tasksArray[indexPath.row].isDone = true
self.doneTasksArr.append(self.tasksArray[indexPath.row])
//STEP2: Delete the task from the tasksArray since it was done.
self.context.delete(self.tasksArray[indexPath.row])
//STEP3: Remove the Row:
self.tasksArray.remove(at: indexPath.row)
//STEP4: Update the Model:
self.saveTasks()
self.tableView.reloadData()
}
//configure btn:
doneAction.backgroundColor = .cyan
return [doneAction]
} else {
let deleteAction = SwipeAction(style: .destructive, title: "Delete") { action, indexPath in
self.context.delete(self.tasksArray[indexPath.row])
self.tasksArray.remove(at: indexPath.row)
self.saveTasks()
self.tableView.reloadData()
}
return [deleteAction]
}
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
}
// MARK: - Class Methods:
#IBAction func addBtnTapped(_ sender: UIBarButtonItem) {
insertNewTask()
}
func insertNewTask() {
var textField = UITextField()
let alert = UIAlertController(title: "New Task", message: "Please Add Your Task", preferredStyle: .alert)
alert.addTextField { (alertTextField) in
alertTextField.placeholder = "Create New Task"
textField = alertTextField
}
let action = UIAlertAction(title: "Add", style: .default) { (action) in
let newItem = Task(context: self.context)
newItem.title = textField.text!
newItem.isDone = false
self.tasksArray.append(newItem)
self.saveTasks()
self.tableView.reloadData()
}
alert.addAction(action)
self.present(alert, animated: true, completion: nil)
}
// MARK: - Sege Section:
#IBAction func segeControlTapped(_ sender: UISegmentedControl) {
switch Sege.selectedSegmentIndex
{
case 0:
//Loading normal tasks which not done
loadTasks()
case 1:
//Loading the doneTasks:
loadDoneTasksFrom()
default:
print("There's something wrong with Sege!")
}
tableView.reloadData()
}
//MARK: - Model Manipulation Methods:
func saveTasks() {
do {
try! context.save()
} catch {
print("Error Saving context \(error)")
}
}
func loadTasks() {
let request: NSFetchRequest<Task> = Task.fetchRequest()
do{
tasksArray = try! context.fetch(request)
} catch {
print("There was an error with loading items \(error)")
}
}
func loadDoneTasksFrom() {
let request: NSFetchRequest<Task> = Task.fetchRequest()
request.predicate = NSPredicate(format: "isDone == %#", "true")
request.sortDescriptors = [NSSortDescriptor(key: "isDone", ascending: false)]
do{
tasksArray = try context.fetch(request)
} catch {
print("Error fetching data from context\(error)")
}
tableView.reloadData()
}
}
You can use one of these
NSPredicate(format: "isDone == %#", NSNumber(value: true))
NSPredicate(format: "isDone = %d", true)
You can write queries like this
static func getDoneTasks() -> NSFetchRequest<Task> {
let request:NSFetchRequest<Task> = Task.fetchRequest() as! NSFetchRequest<Task>
let sortDescriptor = NSSortDescriptor(key: "createdAt", ascending: false)
request.sortDescriptors = [sortDescriptor]
let isDone = true
request.predicate = NSPredicate(format: "isDone == %#", isDone)
return request
}
And then you just fetch them with:
#FetchRequest(fetchRequest: Task.getDoneTasks()) var doneTasks: FetchedResults<Task>
You also can add arguments etc. to your function and pass them in the FetchRequest
I can recommend this tutorial to understand the core concepts of coredata
Yay fellas! I solved it, I splited it to two functions like this: thank you very much for your help ! <3 I've learned how to use CoreData :) much love!.
func loadTasks() {
let request: NSFetchRequest<Task> = Task.fetchRequest()
request.predicate = NSPredicate(format: "isDone == %#", NSNumber(value: false))
request.sortDescriptors = [NSSortDescriptor(key: "isDone", ascending: false)]
do{
tasksArray = try! context.fetch(request)
} catch {
print("There was an error with loading items \(error)")
}
tableView.reloadData()
}
func loadDoneTasksFrom() {
let request:NSFetchRequest<Task> = Task.fetchRequest()
request.predicate = NSPredicate(format: "isDone == %#", NSNumber(value: true))
request.sortDescriptors = [NSSortDescriptor(key: "isDone", ascending: false)]
do{
tasksArray = try context.fetch(request)
} catch {
print("Error fetching data from context\(error)")
}
tableView.reloadData()
}
and then in the Sege for case 0(not done task) I loadTasks, and in case1 I load DoneTasks.
I have an app that takes in user input that is stored in core data. To simplify things, I combined 5 strings from the user inputs, separated them with a comma and then this long string is stored in core data as 1 entity. The comma is separating the individual 'strings' is what makes it a CSV.
The tableview does what it's supposed to do, but the problem lies when I try to export the coredata entries as a csv. I realise that I am not making use of the fetchedStatsArray as I should and thus it is empty. I tried appending the array with NSManagedObject but none of that work. Is there a way to fix this, such that my fetchedStatsArray is filled? If not, is there another way to make sure that when the csv is generated, it will contain all the data from coredata?
Here is most of my code:
import UIKit
import CoreData
import MessageUI
class HistoryController: UITableViewController, NSFetchedResultsControllerDelegate {
let cellId = "cellId"
var fetchedStatsArray: [NSManagedObject] = []
fileprivate lazy var fetchedResultsController: NSFetchedResultsController<AlarmItem> = {
//create fetch request
let fetchRequest: NSFetchRequest<AlarmItem> = AlarmItem.fetchRequest()
//configure fetch request
fetchRequest.sortDescriptors = [NSSortDescriptor(key: "alarmAttributes", ascending: true)]
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: context, sectionNameKeyPath: nil, cacheName: nil)
let managedObjectContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
fetchedResultsController.delegate = self
return fetchedResultsController
}()
func controllerWillChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
tableView.beginUpdates()
}
func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
tableView.endUpdates()
}
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
switch(type) {
case .insert:
if let indexPath = newIndexPath {
tableView.insertRows(at: [indexPath], with: .fade)
}
break;
case .delete:
if let indexPath = indexPath {
tableView.deleteRows(at: [indexPath], with: .fade)
}
break;
case .update:
//this is mostlikely where the problem lies
//self.tableView.reloadData()
if let indexPath = indexPath, let cell = tableView.cellForRow(at: indexPath) {
configureCell(cell, at: indexPath)
}
break;
case .move:
if let indexPath = indexPath {
tableView.deleteRows(at: [indexPath], with: .fade)
}
if let newIndexPath = newIndexPath {
tableView.insertRows(at: [newIndexPath], with: .fade)
}
break;
#unknown default:
print("Something odd is happening")
}
}
override func viewDidLoad() {
super.viewDidLoad()
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
do {
try fetchedResultsController.performFetch()
} catch let err as NSError {
print("Failed to fetch items", err)
}
}
#objc func addAlarmItem(_ sender: AnyObject) {
let alertController = UIAlertController(title: "Add New Item", message: "Please fill in the blanks", preferredStyle: .alert)
let saveAction = UIAlertAction(title: "Save", style: .default) { [unowned self] action in
//combined string of attributes
let myStrings: [String] = alertController.textFields!.compactMap { $0.text }
let myText = myStrings.joined(separator: ",")
self.save(myText)
self.tableView.reloadData()
}
let cancelAction = UIAlertAction(title: "Cancel", style: .destructive, handler: nil)
alertController.addTextField { (textField) in
textField.placeholder = "Enter Name of Engineer"
}
alertController.addTextField { (textField) in
textField.placeholder = "Enter Date of Alarm in DD/MM/YYYY"
}
alertController.addTextField { (textField) in
textField.placeholder = "Enter Time of Alarm in 24h (eg: 2300)"
}
alertController.addTextField { (textField) in
textField.placeholder = "Please indicate True/False (type True or False)"
}
alertController.addTextField { (textField) in
textField.placeholder = "Insert comments (if any), or NIL"
}
if let popoverController = alertController.popoverPresentationController {
popoverController.sourceView = self.view;
popoverController.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0.0, height: 0.0)
popoverController.permittedArrowDirections = []
popoverController.barButtonItem = self.navigationItem.leftBarButtonItem
}
self.present(alertController, animated: true, completion: nil)
}
func save(_ itemName: String) {
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return }
let managedContext = appDelegate.persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "AlarmItem", in: managedContext)!
let item = NSManagedObject(entity: entity, insertInto: managedContext)
item.setValue(itemName, forKey: "alarmAttributes")
do {
try managedContext.save()
tableView.reloadData()
} catch let err as NSError {
print("Failed to save an item", err)
}
}
#objc func exportCSV(_ sender: AnyObject) {
exportDatabase()
}
func exportDatabase() {
let exportString = createExportString()
saveAndExport(exportString: exportString)
}
func saveAndExport(exportString: String) {
let exportFilePath = NSTemporaryDirectory() + "itemlist.csv"
let exportFileUrl = NSURL(fileURLWithPath: exportFilePath)
FileManager.default.createFile(atPath: exportFilePath, contents: NSData() as Data, attributes: nil)
var fileHandle: FileHandle? = nil
do {
fileHandle = try FileHandle(forUpdating: exportFileUrl as URL)
} catch {
print("filehandle has error")
}
if fileHandle != nil {
fileHandle!.seekToEndOfFile()
let csvData = exportString.data(using: String.Encoding.utf8, allowLossyConversion: false)
fileHandle!.write(csvData!)
fileHandle!.closeFile()
let firstActivityItem = NSURL(fileURLWithPath: exportFilePath)
let activityViewController : UIActivityViewController = UIActivityViewController(activityItems: [firstActivityItem], applicationActivities: nil)
activityViewController.excludedActivityTypes = [
UIActivity.ActivityType.assignToContact,
UIActivity.ActivityType.saveToCameraRoll,
UIActivity.ActivityType.postToFlickr,
UIActivity.ActivityType.postToVimeo,
UIActivity.ActivityType.postToTencentWeibo
]
activityViewController.popoverPresentationController?.sourceView = self.view
activityViewController.popoverPresentationController?.permittedArrowDirections = UIPopoverArrowDirection()
activityViewController.popoverPresentationController?.sourceRect = CGRect(x: self.view.bounds.midX, y: self.view.bounds.midY, width: 0, height: 0)
self.present(activityViewController, animated: true, completion: nil)
}
}
func createExportString() -> String {
var alarmAttributes: String?
var export: String = NSLocalizedString("Engineer Name,Date of Alarm,Time of Alarm,True or False,Engineer Comments \n", comment: "")
for (index, AlarmItem) in fetchedStatsArray.enumerated() {
if index <= fetchedStatsArray.count - 1 {
alarmAttributes = AlarmItem.value(forKey: "alarmAttributes") as! String?
let alarmAttributeStrings = alarmAttributes
export += "\(alarmAttributeStrings ?? "0") \n"
}
}
print("the app will now print: \(export) ")
return export
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
let sectionInfo = fetchedResultsController.sections![section]
return sectionInfo.numberOfObjects
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath)
let alarmItem = fetchedResultsController.object(at: indexPath) as NSManagedObject
cell.textLabel?.text = alarmItem.value(forKeyPath: "alarmAttributes") as? String
return cell
}
func tableView(_ tableView: UITableView!, canEditRowAtIndexPath indexPath: NSIndexPath!) -> Bool {
return true
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
guard editingStyle == .delete else { return }
//fetch
let toBeDeleted = fetchedResultsController.object(at: indexPath)
//delete
fetchedResultsController.managedObjectContext.delete(toBeDeleted)
do {
try fetchedResultsController.managedObjectContext.save()
} catch let err as NSError {
print("failed to save item", err)
}
}
func tableView(_tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "AlarmItem", for: indexPath)
configureCell(cell, at: indexPath)
return cell
}
func configureCell(_ cell: UITableViewCell, at indexPath: IndexPath) {
let alarmItem = fetchedResultsController.object(at: indexPath)
//configure cell
cell.textLabel?.text = alarmItem.value(forKeyPath: "alarmAttributes") as? String
}
}
Basically I have an app that takes in user input (in 5 textfields in an alertcontroller) that are all concatenated in to a string to be in a form that looks like it is a row in a csv file and stored to coredata as a entity. This entity will then be displayed in a tableview. I would like to be able to export the csv file to email it elsewhere. All this will be done in the iOS device itself.
I have looked on this website and other websites but to no avail. A large majority of the example code makes use of outdated versions of swift and xcode.
class ViewController: UITableViewController, NSFetchedResultsControllerDelegate {
let cellId = "cellId"
fileprivate lazy var fetchedResultsController: NSFetchedResultsController<AlarmItem> = {
//create fetch request
let fetchRequest: NSFetchRequest<AlarmItem> = AlarmItem.fetchRequest()
//configure fetch request
fetchRequest.sortDescriptors = [NSSortDescriptor(key: "alarmAttributes", ascending: true)]
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
let fetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: context, sectionNameKeyPath: nil, cacheName: nil)
let managedObjectContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
fetchedResultsController.delegate = self
return fetchedResultsController
}()
func controllerWillChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
tableView.beginUpdates()
}
func controllerDidChangeContent(_ controller: NSFetchedResultsController<NSFetchRequestResult>) {
tableView.endUpdates()
}
func controller(_ controller: NSFetchedResultsController<NSFetchRequestResult>, didChange anObject: Any, at indexPath: IndexPath?, for type: NSFetchedResultsChangeType, newIndexPath: IndexPath?) {
switch(type) {
case .insert:
if let indexPath = newIndexPath {
tableView.insertRows(at: [indexPath], with: .fade)
}
break;
case .delete:
if let indexPath = indexPath {
tableView.deleteRows(at: [indexPath], with: .fade)
}
break;
case .update:
if let indexPath = indexPath, let cell = tableView.cellForRow(at: indexPath) {
configureCell(cell, at: indexPath)
}
break;
case .move:
if let indexPath = indexPath {
tableView.deleteRows(at: [indexPath], with: .fade)
}
if let newIndexPath = newIndexPath {
tableView.insertRows(at: [newIndexPath], with: .fade)
}
break;
#unknown default:
print("Something odd is happening")
}
}
override func viewDidLoad() {
super.viewDidLoad()
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
do {
try fetchedResultsController.performFetch()
} catch let err as NSError {
print("Failed to fetch items", err)
}
}
#objc func addAlarmItem(_ sender: AnyObject) {
let alertController = UIAlertController(title: "Add New Item", message: "Please fill in the blanks", preferredStyle: .alert)
let saveAction = UIAlertAction(title: "Save", style: .default) { [unowned self] action in
//combined string of attributes
let myStrings: [String] = alertController.textFields!.compactMap { $0.text }
let myText = myStrings.joined(separator: ", ")
self.save(myText)
self.tableView.reloadData()
}
let cancelAction = UIAlertAction(title: "Cancel", style: .destructive, handler: nil)
alertController.addTextField { (textField) in
textField.placeholder = "Enter Name of Engineer"
}
alertController.addTextField { (textField) in
textField.placeholder = "Enter Date of Alarm in DD/MM/YYYY"
}
alertController.addTextField { (textField) in
textField.placeholder = "Enter Time of Alarm in 24h (eg: 2300)"
}
alertController.addTextField { (textField) in
textField.placeholder = "Please indicate True/False (type True or False)"
}
alertController.addTextField { (textField) in
textField.placeholder = "Insert comments (if any), or NIL"
}
func save(_ itemName: String) {
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return }
let managedContext = appDelegate.persistentContainer.viewContext
let entity = NSEntityDescription.entity(forEntityName: "AlarmItem", in: managedContext)!
let item = NSManagedObject(entity: entity, insertInto: managedContext)
item.setValue(itemName, forKey: "alarmAttributes")
do {
try managedContext.save()
tableView.reloadData()
} catch let err as NSError {
print("Failed to save an item", err)
}
}
#objc func exportCSV(_ sender: AnyObject) {
exportDatabase()
}
func exportDatabase() {
let exportString = createExportString()
saveAndExport(exportString: exportString)
}
func saveAndExport(exportString: String) {
let exportFilePath = NSTemporaryDirectory() + "itemlist.csv"
let exportFileUrl = NSURL(fileURLWithPath: exportFilePath)
FileManager.default.createFile(atPath: exportFilePath, contents: NSData() as Data, attributes: nil)
var fileHandle: FileHandle? = nil
do {
fileHandle = try FileHandle(forUpdating: exportFileUrl as URL)
} catch {
print("filehandle has error")
}
if fileHandle != nil {
fileHandle!.seekToEndOfFile()
let csvData = exportString.data(using: String.Encoding.utf8, allowLossyConversion: false)
fileHandle!.write(csvData!)
fileHandle!.closeFile()
let firstActivityItem = NSURL(fileURLWithPath: exportFilePath)
let activityViewController : UIActivityViewController = UIActivityViewController(activityItems: [firstActivityItem], applicationActivities: nil)
activityViewController.excludedActivityTypes = [
UIActivity.ActivityType.assignToContact,
UIActivity.ActivityType.saveToCameraRoll,
UIActivity.ActivityType.postToFlickr,
UIActivity.ActivityType.postToVimeo,
UIActivity.ActivityType.postToTencentWeibo
]
self.present(activityViewController, animated: true, completion: nil)
}
}
func createExportString() -> String {
var alarmAttributes: String?
var export: String = NSLocalizedString("Engineer Name,Date of Alarm,Time of Alarm,True or False,Engineer Comments \n", comment: "")
for (index, AlarmItem) in fetchedStatsArray.enumerated() {
if index <= fetchedStatsArray.count - 1 {
alarmAttributes = AlarmItem.value(forKey: "alarmAttributes") as! String?
let alarmAttributeStrings = alarmAttributes
export += "\(alarmAttributeStrings ?? "0") \n"
}
}
print("the app will now print: \(export) ")
return export
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
let sectionInfo = fetchedResultsController.sections![section]
return sectionInfo.numberOfObjects
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: cellId, for: indexPath)
let alarmItem = fetchedResultsController.object(at: indexPath) as NSManagedObject
cell.textLabel?.text = alarmItem.value(forKeyPath: "alarmAttributes") as? String
return cell
}
func tableView(_ tableView: UITableView!, canEditRowAtIndexPath indexPath: NSIndexPath!) -> Bool {
return true
}
overr ide func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
tableView.deselectRow(at: indexPath, animated: true)
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
guard editingStyle == .delete else { return }
//fetch
let toBeDeleted = fetchedResultsController.object(at: indexPath)
//delete
fetchedResultsController.managedObjectContext.delete(toBeDeleted)
do {
try fetchedResultsController.managedObjectContext.save()
} catch let err as NSError {
print("failed to save item", err)
}
}
func tableView(_tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "AlarmItem", for: indexPath)
configureCell(cell, at: indexPath)
return cell
}
func configureCell(_ cell: UITableViewCell, at indexPath: IndexPath) {
let alarmItem = fetchedResultsController.object(at: indexPath)
//configure cell
cell.textLabel?.text = alarmItem.value(forKeyPath: "alarmAttributes") as? String
}
}
So, I have been building this project that is a todo app. and when you click on a cell your item should be searched on to ask.com. I now keep getting this fatal error. And it shows up as nil in my "Appurl" part of the code as you can see in my code. When I click on it in the code it shows up as nil which is weird. Moreover, it is causing my app to crash. Source code would be amazing. I have no idea how to fix this. all I know is that the nil shows up in the "Appurl" The fatal error message that comes up is as follows below. I have looked up other answer for this type of fatal error message with no luck.
"thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value"
import UIKit
class NewTableViewController: UITableViewController, NewCellDelegate, {
var news:[News]!
override func viewDidLoad() {
super.viewDidLoad()
loadData()
func loadData() {
news = [News]()
news = DataManager.loadAll(News.self).sorted(by: {$0.createdAt < $1.createdAt})
self.tableView.reloadData()
}
#IBAction func Save(_ sender: Any) {
let addAlert = UIAlertController(title: "ADD", message: "TODO", preferredStyle: .alert)
addAlert.addTextField { (textfield:UITextField) in
textfield.placeholder = "TODO"
}
addAlert.addAction(UIAlertAction(title: "Save", style: .default, handler: { (action:UIAlertAction) in
guard let title = addAlert.textFields?.first?.text else {return}
let newsave = News(title: title, completed: false, createdAt: Date(), itemIdentifier: UUID())
newsave.saveItem()
self.news.append(newsave)
let indexPath = IndexPath(row: self.tableView.numberOfRows(inSection: 0), section: 0)
self.tableView.insertRows(at: [indexPath], with: .automatic)
}))
addAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(addAlert, animated: true, completion: nil)
}
};
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return news.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! NewTableViewCell
cell.delegte = self
let news = self.news[indexPath.row]
cell.label.text = news.title
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
//getting the index path of selected row
let indexPath = tableView.indexPathForSelectedRow
//getting the current cell from the index path
let currentCell = tableView.cellForRow(at: indexPath!) as! NewTableViewCell
//getting the text of that cell
let TODO = currentCell.label.text
let appURL = NSURL(string: "https://www.ask.com/web?q=\
(TODO))&o=0&qo=homepageSearchBox)")
if UIApplication.shared.canOpenURL(appURL! as URL) {
if #available(iOS 10.0, *) {
UIApplication.shared.open(appURL! as URL, options: [:], completionHandler: nil)
} else {
UIApplication.shared.openURL(appURL! as URL)
}
}
}
You need to handle occurrence of spaces and special characters like + in you url string,
For handling spaces,
/**Handle occurance of space in given url string*/
class func handleSpaces(in urlString: String) -> String {
return urlString.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
}
For handling + symbol,
/**Handle occurance of space in given url string*/
class func handlePlusSign(in urlString: String) -> String {
return urlString.replacingOccurrences(of: "+", with: "%2B")
}
To avoid crashes you need to use proper crash resisting conditions like if let and guard let in your app,
e.g
if let url = appURL {
// Proceed to use this url
}
Your code will become,
let indexPath = tableView.indexPathForSelectedRow
//getting the current cell from the index path
guard let currentCell = tableView.cellForRow(at: indexPath!) as? NewTableViewCell else {
print("Can't get your cell")
return
}
//getting the text of that cell
guard let todo = currentCell.label.text else {
print("Error in getting todo string")
return
}
var urlString = "https://www.ask.com/web?q=\(todo))&o=0&qo=homepageSearchBox)"
urlString = urlString.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)! // Handle spaces in your `todo` string.
guard let appURL = URL(string: urlString) else {
print("Can't form url")
return
}
if UIApplication.shared.canOpenURL(appURL) {
if #available(iOS 10.0, *) {
UIApplication.shared.open(appURL, options: [:], completionHandler: nil)
} else {
UIApplication.shared.openURL(appURL)
}
}
Thanks.
I want to fetch contact name and number in same cell but it fetches name in first cell and number in second cell i have added my entire coding here....
import UIKit
import AddressBook
import CoreData
class ContactViewController: UIViewController,CNContactPickerDelegate,UITableViewDelegate,UITableViewDataSource{
var contactStore = CNContactStore()
var mycontact:CNContactStore!
var myContacts = [CNContact]()
var names = [NSManagedObject]()
var numbers = [NSManagedObject]()
var yourcont:NSMutableArray = NSMutableArray()
#IBOutlet weak var FirstTableView: UITableView!
override func viewDidLoad() {
super.viewDidLoad()
navigationController!.navigationBar.barTintColor = UIColor.blueColor()
navigationController!.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: UIColor.whiteColor()]
// Do any additional setup after loading the view.
}
#IBAction func AddButtonTapped(sender: AnyObject) {
let alert = UIAlertController(title: "New Contact",
message: "Add a new contact",
preferredStyle: .Alert)
let saveAction = UIAlertAction(title: "Save",
style: .Default,
handler: { (action:UIAlertAction) -> Void in
let textField = alert.textFields![0] as UITextField
self.saveName(textField.text!)
let sedfield = alert.textFields![1] as UITextField
self.saveNum(sedfield.text!)
self.FirstTableView.reloadData()
})
let cancelAction = UIAlertAction(title: "Cancel",
style: .Default) { (action: UIAlertAction) -> Void in
}
alert.addTextFieldWithConfigurationHandler {
(textField: UITextField) -> Void in
textField.placeholder = "Enter Your Name"
}
alert.addTextFieldWithConfigurationHandler {
(sedfield: UITextField) -> Void in
sedfield.placeholder = "Enter your Number"
}
alert.addAction(saveAction)
alert.addAction(cancelAction)
presentViewController(alert,
animated: true,
completion: nil)
}
func saveName(name: String) {
let appDelegate =
UIApplication.sharedApplication().delegate as! AppDelegate
let managedContext = appDelegate.managedObjectContext
let entity = NSEntityDescription.entityForName("Person",
inManagedObjectContext:managedContext)
let person = NSManagedObject(entity: entity!,
insertIntoManagedObjectContext: managedContext)
person.setValue(name, forKey: "name")
do {
try managedContext.save()
names.append(person)
} catch let error as NSError {
print("Could not save \(error), \(error.userInfo)")
}
}
func saveNum(name: String) {
let appDelegate =
UIApplication.sharedApplication().delegate as! AppDelegate
let managedContext = appDelegate.managedObjectContext
let entity = NSEntityDescription.entityForName("Person",
inManagedObjectContext:managedContext)
let person = NSManagedObject(entity: entity!,
insertIntoManagedObjectContext: managedContext)
person.setValue(name, forKey: "number")
do {
try managedContext.save()
numbers.append(person)
} catch let error as NSError {
print("Could not save \(error), \(error.userInfo)")
}
}
#IBAction func LeftTapped(sender: AnyObject) {
let appDelegate:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
appDelegate.centerContainer?.toggleDrawerSide(MMDrawerSide.Left, animated: true, completion: nil)
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if(section == 0) {
return names.count
}
return numbers.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("ContactCell") as! TableViewCell
let personname = names[indexPath.row]
cell.ConName.text = personname.valueForKey("name") as? String
let personnum = numbers[indexPath.row]
cell.ConNumber.text = personnum.valueForKey("number") as? String
return cell
}
func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool
{
return true
}
func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath)
{
if editingStyle == .Delete
{
numbers.removeAtIndex(indexPath.row)
tableView.reloadData()
}
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
let appDelegate =
UIApplication.sharedApplication().delegate as! AppDelegate
let managedContext = appDelegate.managedObjectContext
let fetchRequest = NSFetchRequest(entityName: "Person")
do {
let results =
try managedContext.executeFetchRequest(fetchRequest)
names = results as! [NSManagedObject]
numbers = results as! [NSManagedObject]
print(results)
} catch let error as NSError {
print("Could not fetch \(error), \(error.userInfo)")
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
Choose Table View Cell on Storyboard and set Style with Subtitle