I am getting the following JSON from Foursquare API and I have been struggling with extracting the data:
{
"meta":{
"code":200,
"requestId":"58122e59498e5506a1b23580"
},
"response":{
"venues":[
{
"id":"4d56c381a747b60cd4a12c2b",
"name":"Sports Circle",
"contact":{},
"location":{
"lat":31.9,
"lng":35.9,
"labeledLatLngs":[
{
"label":"display",
"lat":31.9,
"lng":35.90
}
],
],
"confident":true
}
}
}
I want to get the name in venues in addition to the lat and lng values. I have tried this so far but it gets out of the second if statement at JVenues because it is nil:
func parseData (JSONData: Data){
do {
var readableJson = try JSONSerialization.jsonObject(with: JSONData, options: .mutableContainers) as! [String:AnyObject]
if let JResponse = readableJson ["response"] as? [String:AnyObject] {
if let JVenues = JResponse["venues"] as? [String:AnyObject]{
if let JName = JVenues["name"] as? String{
NSLog(JName)
}
}
}
} catch {
print(error)
}
}
This is what the other answers are getting at. Will probably make more sense if you can see it all laid out...
if let JResponse = readableJson ["response"] as? [String : AnyObject] {
if let JVenues = JResponse["venues"] as? [[String : AnyObject]] {
if let JName = JVenues.first?["name"] as? String {
NSLog(JName)
}
}
}
Note this only gets the FIRST name in the array of venues.
EDIT:
I prefer something like this. Define a struct and convert your dictionaries to the struct:
struct Venue {
var name: String?
var venueId: String?
init(_ venueDictionary: [String : AnyObject]) {
self.name = venueDictionary["name"] as? String
self.venueId = venueDictionary["id"] as? String
}
}
In your class create a property such as:
var venues = [Venue]()
From your JSON map the dictionaries to the venue array. I renamed variables that start with a capital for convention.
if let response = readableJson ["response"] as? [String : AnyObject] {
if let responseVenues = response["venues"] as? [[String : AnyObject]] {
self.venues = responseVenues.map({ Venue($0)) })
}
}
Use anywhere in your class like:
let venue = self.venues.first
print(venue?.name)
Or:
if let venue = self.venues.find({ $0.name == "Sports Circle" }) {
print("found venue with id \(venue.venueId)")
}
Related
Hi I am trying to learn RXSwift and First time I came across these concepts like Maps and Compact Maps.
I am able to get the response, but this line always returns empty.
objects.compactMap(DummyUser.init)
fileprivate let Users = Variable<[DummyUser]>([])
fileprivate let bag = DisposeBag()
response
.filter { response, _ in
return 200..<300 ~= response.statusCode
}
.map { _, data -> [[String: Any]] in
guard (try? JSONSerialization.jsonObject(with: data, options: [])) != nil else {
return []
}
let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String : Any]
// print(json!["results"])
return json!["results"] as! [[String : Any]]
}
.filter { objects in
return objects.count > 0
}
.map { objects in
// objects.forEach{print($0["name"]!)}
let names = objects.map { $0["name"]!}
print(names)
return objects.compactMap(DummyUser.init)
}
.subscribe(onNext: { [weak self] newEvents in
self?.processEvents(newEvents)
})
.disposed(by: bag)
func processEvents(_ newEvents: [DummyUser]) {
var updatedEvents = newEvents + Users.value
if updatedEvents.count > 50 {
updatedEvents = Array<DummyUser>(updatedEvents.prefix(upTo: 50))
}
Users.value = updatedEvents
DispatchQueue.main.async {
self.MianUsertable.reloadData()
}
// refreshControl?.endRefreshing()
let eventsArray = updatedEvents.map{ $0.dictionary } as NSArray
eventsArray.write(to: userFileURL, atomically: true)
}
My Json Response is Here
https://randomuser.me/api/?results=5
DummyUser Class
import Foundation
typealias AnyDict = [String: Any]
class DummyUser {
let gender: String
let name: AnyDict
let dob: String
let picture: AnyDict
init?(dictionary: AnyDict) {
guard let Dgender = dictionary["gender"] as? String,
let Dname = dictionary["name"] as? AnyDict,
let birthdata = dictionary["dob"] as? AnyDict,
let Ddob = birthdata["dob"] as? String,
let Dpicture = dictionary["picture"] as? AnyDict
else {
return nil
}
gender = Dgender
name = Dname
dob = Ddob
picture = Dpicture
}
var dictionary: AnyDict {
return [
"user": ["name" : name, "gender": gender, "dob": dob],
"picture" : ["userImage": picture]
]
}
}
In your DummyUser model you are using failable initializer, so in case of wrong dictionary provided to init method it will return nil.
compactMap automatically automatically filters nil's and that's the reason why your output is empty.
Looking at this piece of code:
let names = objects.map { $0["name"]!}
return objects.compactMap(DummyUser.init)
I would debug this variable called names because it probably has wrong input for the DummyUser initializer. It should be dictionary containing all of your DummyUser parameters. You can also debug your failable initializer to see which of the parameter is missing.
Here I tried to parse the data from my local server but unable to parse it and it returning empty data and below are my model classes from which the data I was passing to an table view which can anyone help me what's wrong in implementing it?
Here I had attached my image which follows the Json format:
Code:
var homePageModel = [HomeBanner]()
func HomeBannerDownloadJsonWithURL(){
let url = URL(string: homePageUrl)!
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
if error != nil { print(error!); return }
do {
if let jsonObj = try JSONSerialization.jsonObject(with: data!) as? [[String:Any]] {
for item in jsonObj {
print(item)
for dict in item {
print(dict)
let dict = HomeBanner(json: item)
self.homePageModel.append(dict!)
print(self.homePageModel)
}
}
print(self.homePageModel)
DispatchQueue.main.async {
self.homeTableView.delegate = self
self.homeTableView.dataSource = self
self.homeTableView.reloadData()
}
}
} catch {
print(error)
}
}
task.resume()
}
struct HomeBanner {
let title : String?
let titleInArabic : String?
let showTitle : String?
var banner = [ChildrenBanners]()
init?(json : [String:Any]) {
if let customAttribute = json["childran_banners"] as? [[String: AnyObject]] {
var result = [ChildrenBanners]()
for obj in customAttribute {
result.append(ChildrenBanners(json: obj as! [String : String])!)
}
self.banner = result
} else {
self.banner = [ChildrenBanners]()
}
self.title = json["title"] as? String ?? ""
print(self.title)
self.titleInArabic = json["title_in_arabic"] as? String ?? ""
self.showTitle = json["show_title"] as? String ?? ""
}
}
struct ChildrenBanners {
let bannerId : String?
let name : String?
let status : String?
let sliderId : String?
let desktopImage : String?
let mobileImage : String?
let imageAlt : String?
let sortOrder : String?
let startTime : String?
let endTime : String?
init?(json : [String:Any]) {
self.bannerId = json["banner_id"] as? String ?? ""
print(self.bannerId)
self.name = json["name"] as? String ?? ""
self.status = json["status"] as? String ?? ""
self.sliderId = json["slider_id"] as? String ?? ""
self.desktopImage = json["desktop_image"] as? String ?? ""
self.mobileImage = json["mobile_image"] as? String ?? ""
self.imageAlt = json["image_alt"] as? String ?? ""
self.sortOrder = json["sort_order"] as? String ?? ""
self.startTime = json["start_time"] as? String ?? ""
self.endTime = json["end_time"] as? String ?? ""
}
}
Just try these lines of code
if let jsonObj = try JSONSerialization.jsonObject(with: data!) as? [[String:Any]] {
self.homePageModel = jsonObj.map{HomeBanner(json: $0)}
print(self.homePageModel)
DispatchQueue.main.async {
self.homeTableView.delegate = self
self.homeTableView.dataSource = self
self.homeTableView.reloadData()
}
}
} catch {
print(error)
}
and there is no necessity of making optional initializer for HomeBanner and ChildrenBanners just use init(json : [String : Any]){} for both struct
Root of json is an array and then second level is dictionary with keys list1, list2 etc. You are missing that in your code. Should be something like this (I haven't compiled it).
if let data = data, let jsonObj = try JSONSerialization.jsonObject(with: data) as? [[String:[String:Any]]] {
for item in jsonObj {
for (_, dict) in item {
if let obj = HomeBanner(json: dict) {
self.homePageModel.append(obj)
}
}
}
}
There are lot of other issues in your code. Like force unwrapping optional. Using same parameters again within a scope. For example.
for dict in item {
let dict = HomeBanner(json: item)
// ....
}
You shouldn't use same param names like you are using dict it hides the scope of the outer dict.
I have a JSON function that previously mapped the contents of an array (countries, divisions, teams (not shown)) into seperate variables using this code:
let task = URLSession.shared.dataTask{ (response: URLResponse?, error: Error?) in
DispatchQueue.main.async
{
if error != nil {
print("error=\(error)")
return
}
do{
let json = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String:AnyObject]
print (json)
if let arr = json?["countries"] as? [[String:String]] {
self.countryId = arr.flatMap { $0["id"]!}
self.countries = arr.flatMap { $0["name"]!}
self.teamsTableView.reloadData()
print ("Countries: ",self.countries)
}
if let arr = json?["divisions"] as? [[String:String?]] {
self.divisions = arr.flatMap { ($0["name"]! )}
self.divisionId = arr.flatMap { ($0["id"]! )}
self.teamsTableView.reloadData()
print ("Divisions: ",self.divisions)
}
} catch{
print(error)
}
}
}
However, I have since learned "that mapping multiple arrays as data source in conjunction with flatMap is pretty error-prone", and that I should use a custom struct instead.
How / Where do I begin to write a custom struct to assign the contents of this JSON array into seperate variables?
Thanks
UPDATE:
I have used the code as suggested below and I believe this is along the right lines. Below is the current output.
Countries: [KeepScore.SumbitScoreViewController.Country(name: Optional("Denmark"), countryId: Optional("1")), KeepScore.SumbitScoreViewController.Country(name: Optional("Belgium"), countryId: Optional("2")), KeepScore.SumbitScoreViewController.Country(name: Optional("Brasil"), countryId: Optional("3")),
However by the looks of it, it is also putting the countryId into the variable and I'd like just the name so I could call it in a UITable...What are the next steps in doing this?
Same idea as you were doing, except instead of mapping each individual property you map the whole country.
//define a struct
struct Country {
var name: String?
var countryId: String?
init(_ dictionary: [String : String]) {
self.name = dictionary["name"]
self.countryId = dictionary["id"]
}
}
//defined in your class
var countries = [Country]()
//when parsing your JSON
let json = try JSONSerialization.jsonObject(with: data!, options: .allowFragments) as? [String:AnyObject]
print (json)
if let arr = json?["countries"] as? [[String : String]] {
self.countries = arr.flatMap { Country($0) }
print ("Countries: ",self.countries)
}
Apply the same idea to divisions.
Edit:
In the code you've posted, you extract both the name and the id, that's why I included both in the struct. So you can remove the id from the struct if you wish, or add other variables in the future. Then when you want to extract them and use them in your table view you just do:
let country = countries[indexPath.row]
cell.textLabel.text = country.name
I am trying to parse some json data into three different arrays based off the label in the json. I seem to be stuck and don't know why my for loop is never being entered. I am new to iOS and am using this to learn swift. Any help will be appreciated.
Here is the code that I am using:
var myPicture = [String]()
var myPath = [String]()
var mylabel = [String]()
let jsonString = "[{\"picture\" : \"Picture 1 \", \"path\": \"Path 1\" , \"label\" : \"Label 1\"}]"
//Convert jsonString to NSData
let myData = jsonString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
do{
let promoJson = try NSJSONSerialization.JSONObjectWithData(myData, options:.AllowFragments)
if let promtions = promoJson[""] as? [[String: AnyObject]] {
for promtions in promtions {
if let picture = promtions["picture"] as? String
{
myPicture.append(picture)
if let path = promtions["path"] as? String
{
myPath.append(path)
if let label = promtions["label"] as? String
{
mylabel.append(label)
}
}
}
}
}
}catch {
print("Error with Json: \(error)")
}
print(myPicture.first)
print(myPath.first)
print(mylabel.first)
The results for the print are all nil. So nothing is being appended to the arrays
The if let promtions = promoJson[""] part won't work and would be useless anyway. This is only promoJson that you have to cast to an array of dictionaries.
You weren't that far from the solution, look at my working version of your code:
do {
let promoJson = try NSJSONSerialization.JSONObjectWithData(myData, options: [])
if let promtions = promoJson as? [[String: AnyObject]] {
for promtion in promtions {
if let picture = promtion["picture"] as? String {
myPicture.append(picture)
}
if let path = promtion["path"] as? String {
myPath.append(path)
}
if let label = promtion["label"] as? String {
mylabel.append(label)
}
}
}
} catch let error as NSError {
print(error.debugDescription)
}
Alternative
Now that the issue is resolved, let me suggest you another way: instead of separate arrays for your data, use one array of objects holding your data.
For example, make a struct like this:
struct Promotion {
let picture: String
let path: String
let label: String
}
And an array for instances of this struct:
var myPromotions = [Promotion]()
Now we can decode the JSON, create objects from it then store them in the array:
do {
let promoJson = try NSJSONSerialization.JSONObjectWithData(myData, options: [])
if let promtions = promoJson as? [[String: AnyObject]] {
for promtion in promtions {
if let picture = promtion["picture"] as? String,
path = promtion["path"] as? String,
label = promtion["label"] as? String {
let promo = Promotion(picture: picture, path: path, label: label)
myPromotions.append(promo)
}
}
}
} catch let error as NSError {
print(error.debugDescription)
}
Now look at the content of the array, very convenient:
for promo in myPromotions {
print(promo.label)
print(promo.path)
print(promo.picture)
}
When you are converting it is already an array.
import Foundation
import UIKit
var myPicture = [String]()
var myPath = [String]()
var mylabel = [String]()
let jsonString = "[{\"picture\" : \"Picture 1 \", \"path\": \"Path 1\" , \"label\" : \"Label 1\"}]"
//Convert jsonString to NSData
let myData = jsonString.dataUsingEncoding(NSUTF8StringEncoding, allowLossyConversion: false)!
do{
let promoJson = try NSJSONSerialization.JSONObjectWithData(myData, options:.AllowFragments) as! NSArray
for promtions in promoJson {
if let picture = promtions["picture"] as? String
{
myPicture.append(picture)
if let path = promtions["path"] as? String
{
myPath.append(path)
if let label = promtions["label"] as? String
{
mylabel.append(label)
}
}
}
}
}catch
{
print("Error with Json: \(error)")
}
print(myPicture.first) // "Optional("Picture 1 ")\n"
print(myPath.first) // "Optional("Path 1")\n"
print(mylabel.first) // "Optional("Label 1")\n"
This does the job.
I've been trying to read this complex JSON Data in Swift, which i can read the "feed" and then "entry" until reaching "url" for each element in the JSON.
This is the JSON (Dictionary - Array - Dictionary - Array - Dictionary ):
{
"feed": {
"entry": [
{
"media$group": {
"media$content": [
{
"url": "http://..../photo.png"
}
]
}
}
]
}
}
This is my Photo Class where i define the things i need to get from JSON:
class Photo {
let TAG_FEED:String = "feed"
let TAG_ENTRY:String = "entry"
let TAG_MEDIA_GROUP:String = "media$group"
let TAG_MEDIA_CONTENT:String = "media$content"
let TAG_IMG_URL:String = "url"
}
This is my UIViewController where I'm trying to read the JSON :
func parseJsonData(data: NSData) -> [Photo] {
var photos = [Photo]()
var error:NSError?
let jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &error) as? NSDictionary
if error != nil {
println(error?.localizedDescription)
}
// how is it possible to read it here
return photos
}
After reading the array is it possible to store it array of Strings.
If you want to parse then use below piece of code and learn.
if let myFeed = jsonResult[TAG_FEED] as? Dictionary<String, AnyObject> {
if let myEntries = myFeed[TAG_ENTRY] as? Array<AnyObject> {
for myEntry in myEntries {
if let myMedia = myEntry[TAG_MEDIA_GROUP] as? Dictionary<String, AnyObject> {
if let contents = myMedia[TAG_MEDIA_CONTENT] as? Array<AnyObject> {
for myContent in contents {
if let url = myContent[TAG_IMG_URL] as? String {
// populate your model class here...
}
}
}
}
}
}
}
Change your jsonResult line to let jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableLeaves, error: &error) as! Dictionary<String, AnyObject>!
As alternative you can use SwiftyJSON