I have a custom class like:
class Tender: NSObject {
public var code = ""
public var name = ""
}
A method returns an array of Tender type. From this array, I want to prepare an array that contains only name.
Example,
public func fetchTenderArray() -> [Tender] {
var tenderArray = [Tender]()
let tender1 = Tender()
tender1.code = "t1"
tender1.name = "tenderName1"
let tender2 = Tender()
tender2.code = "t2"
tender2.name = "tenderName2"
tenderArray.append(tender1)
tenderArray.append(tender2)
return tenderArray
}
Now, I have a method that uses this tenderArray. I need to form an array with the names of [Tender].
public func formTenderNamesArray() -> [String] {
let tenderArray = fetchTenderArray()
var tenderNames = [String]()
for tender in tenderArray {
tenderNames.append(tender.name)
}
return tenderNames // returns ["tenderName1","tenderName2"]
}
Is there a short and a best way to prepare that array of strings using swift3?
Try using map functionality,
it should be something like this.
let tenderArray = fetchTenderArray()
let tenderNames = tenderArray.map {$0.name}
For more information please see this link.
https://useyourloaf.com/blog/swift-guide-to-map-filter-reduce/
//Try this
public func formTenderNamesArray() -> [String] {
let tenderArray = fetchTenderArray()
var tenderNames = (tenderArray as! NSArray).value(forKey: "name") as! [String]
return tenderNames
}
Related
My JSON data look like this image below. Now I wanna merge the value of Shop Type and Promotion into one to use as collection view data. How can I do that?
I just filter the response data from the server like this:
var dataBanDau: [SDFilterModel] = []
var quickData: [SDFilterModel] = []
let filters: [SDFilterModel] = data
self.filterEntries = filters
//let nsarray = NSArray(array: self.filterEntries! , copyItems: true)
// self.filterEntriesStoreConstant = nsarray as! Array
self.dataBanDau = filters
for i in 0..<self.dataBanDau.count {
if self.dataBanDau[i].search_key.count == 0 {
self.quickData.append(self.dataBanDau[i])
}
}
self.quickData = self.quickData.filter {
$0.type != "range"
}
DispatchQueue.main.async {
//Note: Reload TableView
self.quickFilterCollection.reloadData()
completed(true)
}
}
the class SDFilterModel:
class SDFilterModel: DSBaseModel {
var name = String()
var type = String()
var is_expanded = Int()
var search_key = String()
var filterEntries : [SDFilterModel]?
override func copy(with zone: NSZone? = nil) -> Any {
// This is the reason why `init(_ model: GameModel)`
// must be required, because `GameModel` is not `final`.
let copy = SDFilterModel(dict: self.dictionary)
if let arrAttribute = NSArray(array: self.value , copyItems: true) as? [AttributeValueModel] {
copy.value = arrAttribute
}
return copy
}
override init(dict: Dictionary<String, Any>) {
super.init(dict: dict);
value = self.valueParse()
name = dict.getString(forKey: "name")
type = dict.getString(forKey: "type")
search_key = dict.getString(forKey: "search_key")
is_expanded = dict.getInt(forKey: "is_expanded")!
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
var value: [AttributeValueModel] = [];
func valueParse()-> [AttributeValueModel] {
guard let childs = (self.dictionary["value"]) as? [Dictionary<String, AnyObject>]
else { return [] }
var output: [AttributeValueModel] = [];
for aDict in childs {
let item = AttributeValueModel(dict:aDict);
// if type == .Range && item.option_id == "0" {
// item.setRangeOptionID(aValue: item.option_name!)
// }
//
output.append(item);
}
return output;
}
Let be Assume you have let myArray = [1,2,3,4,5,6,7,8]
Now you wanted to square of each and every element in the array,
With for loop you do like this
for item in myArray {
print(item * item)
}
Now assume item = $0
With for map you jus do
myArray.map({ $0 * $0 })
Both will gave same output.
map : Use to do same operation on every element of array.
flatmap : It is used to flattern the array of array.
let myArr = [[1,2,3],[4,5,6,7]]
and you want o/p as [1,2,3,4,5,6,7]
So can get above output with myArr.flatMap({$0})
Now back to your question.
let reqArray = myModel.data.map({ $0.value }).flatMap({ $0 })
First, map gaves you array-of-array of key value but you need a single array, so for that you need to use flatmap.
You can take ref : https://medium.com/#Dougly/higher-order-functions-in-swift-sorted-map-filter-reduce-dff60b5b6adf
Create the models like this
struct Option {
let name: String
let searchKey: String
let id: String
}
struct Model {
let type: String
let name: String
let isExpanded: Bool
let value: [Option]
}
You should get the options array values and join all the arrays
let models:[Model] = //...
let collectionViewArray = models.map { $0.value }.reduce([Option](), +)
Using for loop
var collectionViewArray = [Option]()
for model in models {
collectionViewArray.append(contentsOf: model.value)
}
I currently have my set-up as followed:
I am running a query in Firebase to extract all of the genres within an array of genres, like so:
var genresLabelIndex : [String] = ["Horror", "Fiction", "Romance"]
Then I am creating a blank arrays for each of the genres to be able to store the information of the genres within each of the areas like so:
var horrorData = [InformationForFeed]()
var fictionData = [InformationForFeed]()
var romanceData = [InformationForFeed]()
InformationForFeed looks like so:
class InformationForFeed {
fileprivate var _uploadKey:String!
fileprivate var _userKey:String!
fileprivate var _imageURL:String!
fileprivate var _socialMedia:[String]
var uploadKey:String!{
return _uploadKey
}
var userKey:String!{
return _userKey
}
var imageURL:String!{
return _imageURL
}
init(dictionary:Dictionary<String,AnyObject>, socials: [String]) {
_socialMedia = socials
if let uploadKey = dictionary["upload_key"] as? String {
self._uploadKey = uploadKey
}
if let userKey = dictionary["user_key"] as? String {
self._userKey = userKey
}
if let imageURL = dictionary["imageUrl"] as? String {
self._imageURL = imageURL
}
}
}
I am then creating an Array of the list of genres arrays like so:
1) First I am creating an empty array of arrays like this:
var genreArrayIndex : [[InformationForFeed]] = []
2) Then within my init() of the UIView I am setting what will be in the array like this:
genreArrayIndex = [self.horrorData, self.fictionData, self.romanceData]
I then will run a function called getData() that will run my query and start storing the information.
I store my information of each genre in a tempArray, and then I set the genreArrayIndex[index] to equal the tempArray and then clear the tempArray as seen in getData below.
func getData() {
for genre in genresLabelIndex {
let dbReference = Database.database().reference().child("genres").child(genre)
let query = dbReference.queryLimited(toLast: 6)
query.observeSingleEvent(of: .value, with: { (snapshot : DataSnapshot) in
if snapshot.childrenCount > 0 {
for s in snapshot.children.allObjects as! [DataSnapshot] {
let item = s.value as! Dictionary<String,AnyObject?>
let facebook = (s.childSnapshot(forPath: "social_links").value as? NSDictionary)?["facebook_link"]
let audible = (s.childSnapshot(forPath: "social_links").value as? NSDictionary)?["audible_link"]
let amazon = (s.childSnapshot(forPath: "social_links").value as? NSDictionary)?["amazon_link"]
var socialsArray = [String]()
if facebook != nil {
socialsArray.append(facebook! as! String)
} else {
socialsArray.append("nil")
}
if audible != nil {
socialsArray.append(audible! as! String)
} else {
socialsArray.append("nil")
}
if amazon != nil {
socialsArray.append(amazon! as! String)
} else {
socialsArray.append("nil")
}
let data = InformationForFeed(dictionary: item as Dictionary<String,AnyObject>, socials: socialsArray)
self.newArray.append(data)
}
}
self.genreArrayIndex[self.genreArrayIndexCount] = self.newArray
self.genreArrayIndexCount = self.genreArrayIndexCount + 1
self.newArray.removeAll()
self.internalIndex = self.internalIndex + 1
if self.internalIndex == self.genresLabelIndex.count {
self.tableView.reloadData()
}
})
}
}
My tempArray looks like this:
var newArray = [InformationForFeed]()
The index looks like this:
var genreArrayIndexCount : Int = 0
Now comes the issue....
All of the information is properly being stored in the genreArrayIndex .....but... it is not actually storing the information in the arrays that being stored in genreArrayIndex.
So in other words if you were to print(self.genreArrayIndex) it would be fully populated. But if you were to print(self.fictionData) it would be blank.
How can I resolve this?
Array is a value type. That means its contents are copies. Initializing genreArrayIndex with empty horrorData, (and others) and then filling it with getData() does not also copy the data back into horrorData. I would recommend eliminating
genreArrayIndex = [self.horrorData, self.fictionData, self.romanceData]
and replacing horrorData, fictionData, ... with computed properties. Perhaps like this.
var horrorData: [InformationFeed] {
return genreArrayIndex[0]
}
I want to save an array of any class (e.g let array = SymptomsModel) type into device using NSKeyedArchiver in swift .
I Know how to save an array if SymptomsModel class contains all variables with primitive data types , but don't know how to save it if also contains an array of any other class as its property
Below I have explained my problem with the help of example , please go through it and provide solution.
I have a class
class SymptomsModel: NSObject, NSCoding ,ResponseJSONObjectSerializable {
var slug:String?
var name:String?
var images:[Sym_images]?
var videos:[Sym_videos]?
struct Keys {
static let Name = "name"
static let Slug = "slug"
static let Images = "images"
static let Videos = "videos"
}
required init(json:SwiftyJSON.JSON) {
self.slug = json["slug"].string
self.name = json["name"].string
self.images = [Sym_images]()
if let imagesJSON = json["images"].array {
for(imagesJSON) in imagesJSON {
if let newImages = Sym_images(json: imagesJSON){
self.images?.append(newImages)
}
}
}
self.videos = [Sym_videos]()
if let videosJSONArray = json["videos"].array {
for(videosJSON) in videosJSONArray {
if let newVideos = Sym_videos(json: videosJSON){
self.videos?.append(newVideos)
}
}
}
}
init(dictionary: [String : AnyObject]) {
self.name = dictionary[Keys.Name] as? String
self.slug = dictionary[Keys.Slug] as? String
self.images = dictionary[Keys.Images] as? [Sym_acc_images_objects]
self.videos = dictionary[Keys.Videos] as? [Sym_acc_videos_objects]
}
func encodeWithCoder(archiver: NSCoder) {
archiver.encodeObject(name, forKey: Keys.Name)
archiver.encodeObject(slug, forKey: Keys.Slug)
archiver.encodeObject(images, forKey: Keys.Images)
archiver.encodeObject(videos, forKey: Keys.Videos)
}
required init(coder unarchiver: NSCoder) {
super.init()
name = unarchiver.decodeObjectForKey(Keys.Name) as? String
slug = unarchiver.decodeObjectForKey(Keys.Slug) as? String
self.images = unarchiver.decodeObjectForKey(Keys.Slug) as? [Sym_acc_images_objects]
self.videos = unarchiver.decodeObjectForKey(Keys.Slug) as? [Sym_acc_videos_objects]
}
and a PersistanceManager class to save the data with NskeyedArchiver as
class PersistenceManager {
class private func documentsDirectory() -> NSString {
let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
let documentDirectory = paths[0] as String
return documentDirectory
}
class func saveNSArray(arrayToSave: NSArray, key: String) {
print(" saveNSArray key : \(key)")
let file = documentsDirectory().stringByAppendingPathComponent(key)
NSKeyedArchiver.archiveRootObject(arrayToSave, toFile: file)
}
class func loadNSArray(path: String) -> NSArray? {
print(" loadNSArray key : \(path)")
let file = documentsDirectory().stringByAppendingPathComponent(path)
let result = NSKeyedUnarchiver.unarchiveObjectWithFile(file)
return result as? NSArray
}
}
And Here is my implimentation of saving and then retreiving the array
class ViewController: UIViewController{
var ArraySymptom = [SymptomsModel]()
override func viewDidLoad() {
super.viewDidLoad()
ArraySymptom = loadArray()
//saving data in device
PersistenceManager.saveNSArray(ArraySymptom, key: "Symptom")
//loading data from device
if let value = PersistenceManager.loadNSArray("Symptom") as? [SymptomsModel] {
let images = value[0].images
print("images : \(images)")
let slug = value[0].slug
print("slug : \(slug)")
}
}
Here am able to get the value of slug but not able to fetch images value.
It might be happening because slug is of String type and Images is of Custom Class type .
Please suggest me the way i can get it done .
Is is possible to save these type of arrays with NSKeyedArchiver , so that i can access images value just by retreiving ArraySymptom from device.
Silly mistake it was
I was getting nil in Images because it was decoded with wrong key , it was copy paste mistake
The Error was in this function..
required init(coder unarchiver: NSCoder) {
super.init()
name = unarchiver.decodeObjectForKey(Keys.Name) as? String
slug = unarchiver.decodeObjectForKey(Keys.Slug) as? String
self.images = unarchiver.decodeObjectForKey(Keys.Slug) as? [Sym_images]
self.videos = unarchiver.decodeObjectForKey(Keys.Slug) as? [Sym_videos]
}
And the correct decoding must be
self.images = unarchiver.decodeObjectForKey(Keys.Images) as?
[Sym_images]
self.videos = unarchiver.decodeObjectForKey(Keys.Videos) as?
[Sym_videos]
I have a class called Movie, which as of now, only has a string property called movieTitle.
I have an array of Movie, and using the .contains method returns false even when an object with the same title is in the array. Interestingly enough, .contains works in a playground I made but not in an app setting.
Thanks for the help! I'm fairly new to the programing game so if you and ELI5 things, that would be great!
Here's a snippet of the code I have. What ends up happening, is it just keeps adding the same 10 entries onto the array.
do{
let json = try JSONSerialization.jsonObject(with: data!, options:.allowFragments) as! [String: AnyObject]
if let movieSearch = json["Search"] as? [[String: AnyObject]] {
for movie in movieSearch {
if let title = movie["Title"] as? String {
let newMovie = Movie(movieTitle: title)!
if (!self.movieList.contains(newMovie)) {
self.movieList.append(newMovie)
}
self.tableView.reloadData()
}
}
}
}catch {
print("Error with Json: \(error)")
}
Movie Class
import UIKit
class Movie: NSObject, NSCoding {
// MARK: Properties
struct PropertyKey {
static let movieTitleKey = "title"
}
// MARK: Archiving Paths
static let DocumentsDirectory = FileManager().urls(for: .documentDirectory, in: .userDomainMask).first!
static let ArchiveURL = DocumentsDirectory.appendingPathComponent("Movies")
var movieTitle: String
// MARK: Initialization
init?(movieTitle: String) {
// Initialize stored properties.
self.movieTitle = movieTitle
super.init()
// Initialization should fail if there is no itemName
if movieTitle.isEmpty {
return nil
}
}
// MARK: NSCoding
func encode(with aCoder: NSCoder) {
aCoder.encode(movieTitle, forKey: PropertyKey.movieTitleKey)
}
required convenience init?(coder aDecoder: NSCoder) {
let title = aDecoder.decodeObject(forKey: PropertyKey.movieTitleKey) as! String
//Must call designated initializer.
self.init(movieTitle: title)
}
}
// MARK: Equatable
func ==(lhs: Movie, rhs: Movie) -> Bool { // Implement Equatable
return lhs.movieTitle == rhs.movieTitle
}
What works in playgrounds
class Movie: NSObject {
var movieTitle: String
init?(movieTitle: String) {
// Initialize stored properties.
self.movieTitle = movieTitle
super.init()
// Initialization should fail if there is no itemName
if movieTitle.isEmpty {
return nil
}
}
}
var movieList = [Movie]()
var movie1 = Movie(movieTitle: "Batman")
var movie2 = Movie(movieTitle: "Batman")
var movie3 = Movie(movieTitle: "Superman")
movieList.append(movie1!)
movieList.append(movie2!)
movieList.contains(movie1!) // Returns True
movieList.contains(movie3!) // Returns False
Because your Movie class (why is it a class?) inherits from NSObject (why?), it inherits NSObject's conformance of the Equatable protocol, with the NSObject implementation of ==. By default, this does identity comparison (comparing references), rather than value comparison.
Here's an example:
let movie1 = Movie(movieTitle: "Batman")
let movie2 = Movie(movieTitle: "Batman")
var movieList = [Movie1]
movieList.contains(movie1!) // True, because movie1 was added in
movieList.contains(movie2!) // False, movie2 was never added
Since Movie doesn't override == with an implementation that compares its value(s) (such as movieTitle), it defers to the default implementation, which is comparing the references. Even though movie2 has the same value, it's a distinct object with its own (separate) memory location. Thus, the identity comparison fails, and it's not found.
To solve this implement == to return true iff all the fields of Movie match up. What you're trying to do may be better off being implemented with structs, however.
you should try with this way.
var filtered = [Movie]()
filtered = movieList.filter({$0.movieTitle == "Superman"})
if filtered.count == 1 {
//so,"Superman" movie contained in array..
}
let me know the results... thanks.
Just try this code it works perfectly.
do{
let json = try JSONSerialization.jsonObject(with: data!, options:.allowFragments) as! [String: AnyObject]
if let movieSearch = json["Search"] as? [[String: AnyObject]] {
for movie in movieSearch {
if let title = movie["Title"] as? String {
let newMovie = Movie(movieTitle: title)!
let movieTitles = (self.movieList as NSArray).value(forKeyPath: "movieTitle") as? [String]
if movieTitles == nil || movieTitles!.contains(title) == false {
self.movieList.append(newMovie)
}
self.tableView.reloadData()
}
}
}
}catch {
print("Error with Json: \(error)")
}
Try overriding isEqual method of NSObject since it is already conforming Equatable protocol. You can test the code below in a playground. Hope it helps.
class Movie: NSObject {
var movieTitle: String
init?(movieTitle: String) {
// Initialize stored properties.
self.movieTitle = movieTitle
super.init()
// Initialization should fail if there is no itemName
if movieTitle.isEmpty {
return nil
}
}
override func isEqual(_ object: Any?) -> Bool {
guard let theMovie = (object as? Movie) else { return false }
return movieTitle == theMovie.movieTitle
}
}
var movieList = [Movie]()
func appendToList(newMovie: Movie) {
if (!movieList.contains(newMovie)) {
movieList.append(newMovie)
}
}
var movie1 = Movie(movieTitle: "Batman")
var movie2 = Movie(movieTitle: "Batman")
var movie3 = Movie(movieTitle: "Superman")
appendToList(newMovie: movie1!)
movieList.count // count is 1
appendToList(newMovie: movie2!)
movieList.count // count is still 1 not incremented
movieList.contains(movie1!) // Returns true
movieList.contains(movie2!) // Returns true
movieList.contains(movie3!) // Returns false
I am trying to save a copy of my custom class to a file, my class has 2 arrays of CGPoints which I append to every so often, they look like this:
class BlockAttributes: NSObject {
var positions:[CGPoint] = []
var spawns:[CGPoint] = []
}
Everything is working great as far as just as using and accessing the class goes, but archiving it does not work. I can archive arrays of Strings, Bools, and Ints just fine in my other classes but my game fails every time I try to use NSCoder to encode my arrays of CGPoints. Here is my code for archiving:
func encodeWithCoder(coder: NSCoder!) {
coder.encodeObject(positions, forKey: "positions")
coder.encodeObject(spawns, forKey: "spawns")
}
....
class ArchiveData: NSObject {
var documentDirectories:NSArray = []
var documentDirectory:String = ""
var path:String = ""
func saveData(data: BlockAttributes) {
documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
documentDirectory = documentDirectories.objectAtIndex(0) as! String
path = documentDirectory.stringByAppendingPathComponent("data.archive")
if NSKeyedArchiver.archiveRootObject(data, toFile: path) {
print("Success writing to file!")
} else {
print("Unable to write to file!")
}
}
func retrieveData() -> NSObject {
var dataToRetrieve = BlockAttributes()
documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true)
documentDirectory = documentDirectories.objectAtIndex(0) as! String
path = documentDirectory.stringByAppendingPathComponent("data.archive")
if let dataToRetrieve2 = NSKeyedUnarchiver.unarchiveObjectWithFile(path) as? BlockAttributes {
dataToRetrieve = dataToRetrieve2 as BlockAttributes
}
return(dataToRetrieve)
}
}
....
And to save:
let archiveData = ArchiveData()
archiveData.saveData(myBlockActionsObject)
I even tried creating my own custom class to save the CGPoints to, which I call MyCGPoint (I read somewhere on SO that creating custom classes for some data types resolves some NSCoder issues):
class MyCGPoint: NSObject {
var x: CGFloat = 0.0
var y: CGFloat = 0.0
init(X: CGFloat, Y: CGFloat) {
x = X
y = Y
}
override init() {
}
}
....
class BlockAttributes: NSObject {
var positions:[MyCGPoint] = []
var spawns:[MyCGPoint] = []
}
But alas, I am still getting this error:
[Game.MyCGPoint encodeWithCoder:]:
unrecognized selector sent to instance 0x137f1d1a0 Game[20953:5814436]
*** Terminating app due to uncaught exception 'NSInvalidArgumentException',
reason: '-[Game.MyCGPoint encodeWithCoder:]:
unrecognized selector sent to instance 0x137f1d1a0'
Any idea how I can use encodeObject to encode my array of CGPoints/MyCGPoints?
You can convert them to and from strings:
//To string
let point = CGPointMake(0, 0)
let string = NSStringFromCGPoint(point)
//Or if you want String instead of NSString
let string = String(point)
//From string
let point2 = CGPointFromString(string)
CGPoint (and its Cocoa's twin NSPoint) are structs, i.e. value type, so you can't encode them directly. Wrap them in NSValue:
let positionValues = positions.map { NSValue(point:$0) }
let spawnValues = spawns.map { NSValue(point:$0) }
coder.encodeObject(positionValues, forKey: "positions")
coder.encodeObject(spawnValues, forKey: "spawns")
// Decode:
positons = (coder.decodeObjectForKey("positions") as! [NSValue]).map { $0.pointValue }
spawns = (coder.decodeObjectForKey("spawns") as! [NSValue]).map { $0.pointValue }
When you write your custom wrapper class, you have to make it compliant with NSCoding too, which NSValeu had already done for you, for free.