How do you get at a row of type SQLite.Row using the row number?
This is order to populate a picker using the results Array.
Thanks
var allCountries:Array<Any>?
let countries = Table("Country")
let id = Expression<Int64>("rowid")
let name = Expression<String>("Name")
let code = Expression<String>("Code")
func pickerView(_ pickerView:UIPickerView, titleForRow row: Int, forComponent component:Int) -> String?{
return allCountries?[row].*somethingHere* as String
//The array is populated with rows of type SQLite.Row
}
func getCountries() -> Array<Any>{
var results:Array<Any>?
do{
let path = Bundle.main.path(forResource: "location", ofType: "sqlite")
let db = try Connection(path!, readonly: true)
results = Array(try db.prepare(countries))
}
catch{
print("Error")
}
return results!
}
Resolved - needed to return an Array<SQLite.Row>, not <Any>.
Related
Swift (v 5/5.1) newbie here, having a hard time with Codables...hoping to get some advise from the experts here.
Okay, I have a simple dictionary from struct where the key is a string. I want to store the dictionary in UserDefaults (and later retrieve). There are some quite similar questions here, but these are mainly addressing nested struct's.
First attempt (error handling removed for simplicity):
public struct PriceStruct:Codable {
var myPrice: Double
var myTime: TimeInterval
var selected: Bool
var direction: Int
var myHigh, myLow: Double
enum CodingKeys: String, CodingKey {
case myPrice = "myPrice"
case myTime = "myTime"
case selected = "selected"
case direction = "direction"
case myHigh = "myHigh"
case myLow = "myLow"
}
}
var myPrices: [String: PriceStruct] = [:]
// [fill myPrices with some data...]
func savePrices() {
// error: Attempt to set a non-property-list object
UserDefaults.standard.set(myPrices, forKey: "prices")
}
func loadPrices() {
// obviously this doesn't work either
let myPrices = UserDefaults.standard.data(forKey: "prices")
}
While I assumed from the documentation, that UserDefaults is capable of storing dictionaries, it doesn't - at least for me.
Next thing I tried was using JSONEncoder like this:
// this time with prior JSON encoding
func savePrices() {
// this works
let json = try! JSONEncoder().encode(myPrices)
UserDefaults.standard.set(json as Data, forKey: "prices")
}
func loadPrices() {
// this doesn't work
let json = UserDefaults.standard.data(forKey: "prices")
let decoder = JSONDecoder()
let decoded = try! decoder.decode(PriceStruct.self, from json!)
}
Unfortunately I'm getting an error when trying to load data back from UserDefaults:
Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "myPrice", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \"myPrice\", intValue: nil) (\"myPrice\").", underlyingError: nil))
Other variants I tried is converting the encoded JSON to an UTF8 encoded string and storing/retrieving this one:
func savePrices() {
// this works too
let json = try! JSONEncoder().encode(myPrices)
UserDefaults.standard.set(String(data: json, encoding: .utf8), forKey: "prices")
}
func loadPrices() {
// and this doesn't work either
let json = UserDefaults.standard.string(forKey: "prices")!.data(using: .utf8)
}
So, from the error raised, CodingKeys seems to be the root of the problem. I tried to switch over using NSKeyedArchiver and NSKeyedUnarchiver` with no success.
I'm really wondering if there is a simple/universal solution to save/load a Dictionary in UserDefaults?
All your comments and suggestions are appreciated. Thanks!
I tried with the below code in my project that will work for me.
User Model
public protocol UserModel: Codable, PrimaryKey {
var id: String { get }
var firstName: String? { get }
var lastName: String? { get }
var userName: String? { get }
var emails: [String] { get }
}
public struct User: UserModel {
public let id: String
public let firstName: String?
public let lastName: String?
public let userName: String?
public let emails: [String]
public enum CodingKeys: String, CodingKey {
case id = "Id"
case firstName = "FirstName"
case lastName = "LastName"
case userName = "UserName"
case emails = "Emails"
}
public init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
do {
self.id = try container.decode(String.self, forKey: .id)
self.firstName = try container.decodeIfPresent(String.self, forKey: .firstName)
self.lastName = try container.decodeIfPresent(String.self, forKey: .lastName)
self.userName = try container.decodeIfPresent(String.self, forKey: .userName)
self.emails = try container.decodeIfPresent([String].self, forKey: .emails) ?? []
}
catch let error {
debugPrint(error)
throw error
}
}
}
I have stored in userDefault using below way
User Data Class
class UserData: NSObject
{
let userDefaultKey = "user_information"
var userData: User?
func getDictionary() -> [String: Data]
{
var dicInfo = [String: Data]()
do
{
let _userData = try JSONEncoder().encode(userData)
dicInfo["userData_default"] = _userData
}catch let error{
print("error while save data in User Default: \(error.localizedDescription)")
}
return dicInfo
}
func saveToDefault()
{
let userDefault = UserDefaults.standard
userDefault.set(getDictionary(), forKey: userDefaultKey)
userDefault.synchronize()
}
func loadFromDefault()
{
let userDefault = UserDefaults.standard
if let dicInfo = userDefault.object(forKey: userDefaultKey) as? [String: Data]
{
update(dicInfo)
}
}
func update(_ dictionaryInfo: [String: Data])
{
do
{
if let _userData_data = dictionaryInfo["userData_default"]
{
if let _userData = try? JSONDecoder().decode(User.self, from: _userData_data) {
userData = _userData
}
}
saveToDefault()
}catch let error{
print("error while load From Default data in User Default: \(error.localizedDescription)")
}
}
}
Hope this will help you.
The goal here is to retrieve all the documents of a Firestore Database, then putting the data of those retrieved documents into a Table View. I'm using Xcode and Firebase.
For example, if I had a Firestore database with this data and documents:
Document 1
Name: Bob
Email: bob#gmail.com
Phone: 408-111-1234
Document 2
Name: Joe
Email: joe#yahoo.com
Phone: 408-338-4321
I would like to have it all in a table view, maybe something like this:
Bob - bob#gmail.com - 408-111-1234
Joe - joe#yahoo.com - 408-338-4321
So far, I have this set up:
TableViewController:
class PeopleViewController: UITableViewController {
#IBOutlet var table: UITableView!
var peopleArray = [] as [Array<Any>]
private var document: [DocumentSnapshot] = []
override func viewDidLoad() {
super.viewDidLoad()
table.tableFooterView = UIView(frame: CGRect.zero)
self.table.delegate = self
self.table.dataSource = self
loadData()
}
And the loadData() func:
func loadData() {
FirebaseFirestore.root.collection("users").getDocuments { (snapshot, error) in
if let error = error {
print(error.localizedDescription)
} else {
if let snapshot = snapshot {
for document in snapshot.documents {
let data = document.data()
let name = data["name"] as? String ?? ""
let email = data["email"] as? String ?? ""
let phone = data["phone"] as? String ?? ""
let newPerson = ["name": name, "email": email, "phone": phone]
self.peopleArray.append(newPerson)
print(self.peopleArray)
}
self.table.reloadData()
}
}
}
}
The first thing wrong here is that there is this error:
Cannot convert value of type '[String : String]' to expected argument type '[Any]'
When I try to append a newPerson in the PeopleArray. I have searched this up, but none of the answers matched this specific error. The second thing is that I have no clue how to even start adding the data from the PeopleArray into the Table View.
I would love some help for both the error and the Table View. Anything is appreciated!
––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––
After doing what Vadian recommended, I am stuck with a new error.
attempt to insert row 2 into section 0, but there are only 1 rows in section 0 after the update
This is the updated func loadData:
func loadData() {
FirebaseFirestore.root.collection("users").getDocuments { (snapshot, error) in
if let error = error {
print(error.localizedDescription)
} else {
if let snapshot = snapshot {
for document in snapshot.documents {
self.table.beginUpdates()
let data = document.data()
let name = data["name"] as? String ?? ""
let zip = data["zip"] as? String ?? ""
let sport = data["sport"] as? String ?? ""
let newPerson = Person(name: name, zip: zip, sport: sport)
self.people.append(newPerson)
let newIndexPath = IndexPath(row: self.people.count, section: 0)
self.table.insertRows(at: [newIndexPath], with: .automatic)
self.table.endUpdates()
}
DispatchQueue.main.async {
self.table.reloadData()
}
}
}
}
}
I've read about this on another question about how the rows are off by 1, but even when I let indexPath equal to people.count+1 or people.count+2, the error persists. What am I doing wrong?
First of all the syntax
var peopleArray = [] as [Array<Any>]
is bad practice. If you want to declare an empty array write
var peopleArray : [Array<Any>] = []
or
var peopleArray = [Array<Any>]()
Second of all your array is a nested array which is not intended. You mean
var peopleArray = Array<Any>()
which is more descriptive using the alternative syntax
var peopleArray = [Any]()
Third of all as your data is clearly a more specific type than [Any] declare the array
var peopleArray = [[String:String]]()
This fixes the error.
Fourth of all the recommended data source is a custom struct
struct Person {
let name, email, phone: String
}
In this case declare the array (we know that people is plural so the suffix array is redundant).
var people = [Person]()
And populate it (you might reload the table view on the main thread)
for document in snapshot.documents {
let data = document.data()
let name = data["name"] as? String ?? ""
let email = data["email"] as? String ?? ""
let phone = data["phone"] as? String ?? ""
let newPerson = Person(name: name, email: email, phone: phone)
self.people.append(newPerson)
}
DispatchQueue.main.async {
self.table.reloadData()
}
I researched a lot and fixed the edited part in the question I posted. A simple -1 in the insert rows fixed the problem.
let newIndexPath = IndexPath(row: self.people.count-1, section: 0)
Vadian also helped me with the original problem, which was using
var peopleArray = [[String:String]]()
instead of the other incorrect format. I was then able to find how to insert rows by just simply using the table.insertrows function.
(I'm just posting this for a simplified answer for anyone else experiencing problems).
In Swift 2 the following code was working:
let request = NSFetchRequest(entityName: String)
but in Swift 3 it gives error:
Generic parameter "ResultType" could not be inferred
because NSFetchRequest is now a generic type. In their documents they wrote this:
let request: NSFetchRequest<Animal> = Animal.fetchRequest
so if my result class is for example Level how should I request correctly?
Because this not working:
let request: NSFetchRequest<Level> = Level.fetchRequest
let request: NSFetchRequest<NSFetchRequestResult> = Level.fetchRequest()
or
let request: NSFetchRequest<Level> = Level.fetchRequest()
depending which version you want.
You have to specify the generic type because otherwise the method call is ambiguous.
The first version is defined for NSManagedObject, the second version is generated automatically for every object using an extension, e.g:
extension Level {
#nonobjc class func fetchRequest() -> NSFetchRequest<Level> {
return NSFetchRequest<Level>(entityName: "Level");
}
#NSManaged var timeStamp: NSDate?
}
The whole point is to remove the usage of String constants.
I think i got it working by doing this:
let request:NSFetchRequest<NSFetchRequestResult> = NSFetchRequest(entityName: "Level")
at least it saves and loads data from DataBase.
But it feels like it is not a proper solution, but it works for now.
The simplest structure I found that works in 3.0 is as follows:
let request = NSFetchRequest<Country>(entityName: "Country")
where the data entity Type is Country.
When trying to create a Core Data BatchDeleteRequest, however, I found that this definition does not work and it seems that you'll need to go with the form:
let request: NSFetchRequest<NSFetchRequestResult> = Country.fetchRequest()
even though the ManagedObject and FetchRequestResult formats are supposed to be equivalent.
Here are some generic CoreData methods that might answer your question:
import Foundation
import Cocoa
func addRecord<T: NSManagedObject>(_ type : T.Type) -> T
{
let entityName = T.description()
let context = app.managedObjectContext
let entity = NSEntityDescription.entity(forEntityName: entityName, in: context)
let record = T(entity: entity!, insertInto: context)
return record
}
func recordsInTable<T: NSManagedObject>(_ type : T.Type) -> Int
{
let recs = allRecords(T.self)
return recs.count
}
func allRecords<T: NSManagedObject>(_ type : T.Type, sort: NSSortDescriptor? = nil) -> [T]
{
let context = app.managedObjectContext
let request = T.fetchRequest()
do
{
let results = try context.fetch(request)
return results as! [T]
}
catch
{
print("Error with request: \(error)")
return []
}
}
func query<T: NSManagedObject>(_ type : T.Type, search: NSPredicate?, sort: NSSortDescriptor? = nil, multiSort: [NSSortDescriptor]? = nil) -> [T]
{
let context = app.managedObjectContext
let request = T.fetchRequest()
if let predicate = search
{
request.predicate = predicate
}
if let sortDescriptors = multiSort
{
request.sortDescriptors = sortDescriptors
}
else if let sortDescriptor = sort
{
request.sortDescriptors = [sortDescriptor]
}
do
{
let results = try context.fetch(request)
return results as! [T]
}
catch
{
print("Error with request: \(error)")
return []
}
}
func deleteRecord(_ object: NSManagedObject)
{
let context = app.managedObjectContext
context.delete(object)
}
func deleteRecords<T: NSManagedObject>(_ type : T.Type, search: NSPredicate? = nil)
{
let context = app.managedObjectContext
let results = query(T.self, search: search)
for record in results
{
context.delete(record)
}
}
func saveDatabase()
{
let context = app.managedObjectContext
do
{
try context.save()
}
catch
{
print("Error saving database: \(error)")
}
}
Assuming that there is a NSManagedObject setup for Contact like this:
class Contact: NSManagedObject
{
#NSManaged var contactNo: Int
#NSManaged var contactName: String
}
These methods can be used in the following way:
let name = "John Appleseed"
let newContact = addRecord(Contact.self)
newContact.contactNo = 1
newContact.contactName = name
let contacts = query(Contact.self, search: NSPredicate(format: "contactName == %#", name))
for contact in contacts
{
print ("Contact name = \(contact.contactName), no = \(contact.contactNo)")
}
deleteRecords(Contact.self, search: NSPredicate(format: "contactName == %#", name))
recs = recordsInTable(Contact.self)
print ("Contacts table has \(recs) records")
saveDatabase()
This is the simplest way to migrate to Swift 3.0, just add <Country>
(tested and worked)
let request = NSFetchRequest<Country>(entityName: "Country")
Swift 3.0 This should work.
let request: NSFetchRequest<NSFetchRequestResult> = NSManagedObject.fetchRequest()
request.entity = entityDescription(context)
request.predicate = predicate
I also had "ResultType" could not be inferred errors. They cleared once I rebuilt the data model setting each entity's Codegen to "Class Definition". I did a brief writeup with step by step instructions here:
Looking for a clear tutorial on the revised NSPersistentContainer in Xcode 8 with Swift 3
By "rebuilt" I mean that I created a new model file with new entries and attributes. A little tedious, but it worked!
What worked best for me so far was:
let request = Level.fetchRequest() as! NSFetchRequest<Level>
I had the same issue and I solved it with the following steps:
Select your xcdatamodeld file and go to the Data Model Inspector
Select your first Entity and go to Section class
Make sure that Codegen "Class Definition" is selected.
Remove all your generated Entity files. You don't need them anymore.
After doing that I had to remove/rewrite all occurences of fetchRequest as XCode seem to somehow mix up with the codegenerated version.
HTH
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
func loadItemsCategory() {
let request: NSFetchRequest<Category> = Category.fetchRequest()
do {
categoryArray = try context.fetch(request)
} catch {
print(error)
}
tableView.reloadData()
}
func backBtnAction(){
var index = collectionView?.indexPathsForSelectedItems() as! [NSIndexPath]
collectionView?.scrollEnabled = true
collectionView?.reloadItemsAtIndexPaths(index)
}
how to get indexpath in the collectionview... like I am doing
var index = collectionView?.indexPathsForSelectedItems() as! [NSIndexPath]
indexPathsForSelectedItems() returns [NSIndexPath]? so the usual way is optional binding without casting
func backBtnAction()
{
if let indexes = collectionView?.indexPathsForSelectedItems() {
collectionView!.scrollEnabled = true
collectionView!.reloadItemsAtIndexPaths(indexes)
}
}
let verbList: [String] = ["hacer", "ser", "estar"]
let POVList: [String] = ["él / usted","ella / usted","ellas / ustedes","ellos / ustedes","tú","yo","nosotros",]
let correctConjugation: [[String]] = [["hace","hace","hacen","hacen","haces","hago","hacemos"], ["es","es","son","son","eres","soy","somos"], ["está","está","estan","estan","estas","estoy","estamos"]]
func randomVerb() -> Int { //creates and returns a random number for the prefix arrray
var randomVerb = Int(arc4random_uniform(3))
return randomVerb
}
func randomPrefix() -> Int { //creates and returns a random number for the verb array
var randomPrefix = Int(arc4random_uniform(7))
return randomPrefix
}
#IBAction func changeVerb(sender: AnyObject) {
Verb.text = verbList[randomVerb()]
POV.text = POVList[randomPrefix()]
userResponse.backgroundColor = UIColor.whiteColor()
userResponse.text = ""
}
#IBAction func checkResponse(sender: AnyObject) {
var userResponseA: String
userResponseA = userResponse.text
if (userResponseA == correctConjugation[randomVerb()[randomPrefix()]]){
userResponse.backgroundColor = UIColor.greenColor()
} else {
userResponse.backgroundColor = UIColor.redColor()
}
}
So I get two errors here (in the if statement in checkResponse): first, "int does not have a member named 'subscript'" and if I just take out the call for the function in the if statement I get: "'String' is not convertible to 'Mirror Disposition'"
I really have no idea why this is not working. Bear with me, as I am an Xcode noob just trying to get a better grade in spanish.
Very close - just need to have your subscripts separated:
if (userResponseA == correctConjugation[randomVerb()][randomPrefix()]) {
// ...
}
When working with an array of arrays (in this case correctConjugation), each subscript takes you one level down.
For the other issue, you want a couple variables to hold the current verb and prefix indexes:
class VC: UIViewController {
// list declarations here
var verbIndex = 0
var povIndex = 0
#IBAction func changeVerb(sender: AnyObject) {
verbIndex = randomVerb()
povIndex = randomPrefix()
Verb.text = verbList[verbIndex]
POV.text = POVList[povIndex]
userResponse.backgroundColor = UIColor.whiteColor()
userResponse.text = ""
}
#IBAction func checkResponse(sender: AnyObject) {
var userResponseA = userResponse.text
if (userResponseA == correctConjugation[verbIndex][povIndex]){
userResponse.backgroundColor = UIColor.greenColor()
} else {
userResponse.backgroundColor = UIColor.redColor()
}
}
}