I am getting some data from firestore. The problem is that they are in a format that I don't know how to use. This is the data I
receive:
"["TestKey3": <__NSArrayM 0x600002d30b10>(
ArrayElement1,
ArrayElement2,
ArrayElement3
)
, "TestKey5": 12345, "TestKey4": 1, "TestKey2": TestValue2, "TestKey1": TestValue1]
"
And this is the data type:"DataType: Dictionary<String, Any>". Dictionary seems okay normal. I can use dictionary as normal. I need to unwrap Optional and then it is okay.
5 is Int, 4 is Bool, 3 is array, 2 and 1 is string.
The problem is is the array. Even though I have have unwrapped the dictionary, I need to unwrap the array again. It is a __NSArrayM, so I can't use it as a native/swift array, which I want, like using append(). How do I convert it?
This is the script:
static func getData(collectionName: String, documentName: String) {
let docRef = db.collection(collectionName).document(documentName)
docRef.getDocument { (document, error) in
if let document = document, document.exists {
let dataDescription = document.data()
guard var output = dataDescription else {
return
}
print("Getting data at: /\(collectionName)/\(documentName)")
print("DataType: \(type(of: output))")
print(output)
} else {
print("Error getting data at: /\(collectionName)/\(documentName)")
}
}
}`
I want to use "completion: #escaping ([String: Any]?) -> Void)" on the function, so it can wait, but don't know what exactly it should be.
Related
I realise that I am missing something simple but as a Swift newbie I am going around in circles & would appreciate a pointer as to what I am doing wrong?!
I have a Core Data Entity called "Numbers" with an attribute (Int16) called "userNumbers". I am fetching the results like:
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let context = appDelegate.persistentContainer.viewContext
let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Numbers")
//request.predicate = NSPredicate(format: "age = %#", "12")
request.returnsObjectsAsFaults = false
do {
let result = try context.fetch(request)
for data in result as! [NSManagedObject] {
print("\(data.value(forKey: "userNumbers") as! Int16)")
}
} catch {
print("Failed")
}
The result in my console is:
12
13
18
19
21
I need to know how to make this a comma separated list so I can use it in an array. Essentially I need the return to be: 12,13,18,19,21
Everything I try seems to be wrong!
First of all create a more specific fetch request to get a distinct result type
let request = NSFetchRequest<Numbers>(entityName: "Numbers")
A comma separated list is not possible because the type of userNumbers is numeric.
You can map the result to an array of Int16 with
do {
let result = try context.fetch(request) // the type is [Numbers]
let numberArray = result.map{$0.userNumbers}
print(numberArray)
}
I am getting a JSON from an API. So, I want to store a particular value with key SKU. So, what I did was:
var skuArr = [""]
{ (response, error) in
if (error != nil)
{
print("Error \(error.debugDescription)")
}
else
{
self.coinsArr = response.arrayObject as? Array<Dictionary<String, Any>>
for i in 0 ..< (self.coinsArr?.count)!
{
self.skuArr = [response[i]["sku"].rawValue as! String]
}
}
So, with this I am getting the array in skuArr, but when i is 0 I am getting ["a"], and when i is 1 I want it to be ["a","b"], but it gives ["b"] only and when the loop ends with only the last value and not with ["a","b","c","d"] which I want as the final result. How can I insert each of them in the Array?
First of all declare skuArr as empty string array.
var skuArr = [String]()
And this is Swift. There are better ways than ugly index based loops to extract data for example with map or compactMap
if let result = response.arrayObject as? Array<Dictionary<String, Any>> {
self.coinsArr = result
self.skuArr = result.compactMap{ $0["sku"] as? String }
}
And why is coinsArr declared as optional as you are going to force unwrap it anyway? It's highly recommended to use non-optional types as much as possible. Non-optionals can never cause a well-liked unexpected found nil crash
Don't use this:
self.skuArr = [response[i]["sku"].rawValue as! String]
As this will replace the previous value with new one.
Use .append to insert into array.
self.skuArr.append([response[i]["sku"].rawValue as! String])
EDIT
change your initialisation as below:
skuArr: [String] = []
I am trying to access data from a json file. The problem is that some of the values are NSSingleObjectArrays (Arrays with only item) which I can't turn into strings.
class CarObject {
var pictureURL: String!
var carURL: String!
var carPrice: String!
required init(json: [String: AnyObject]) {
pictureURL = json["galleryURL"] as! String
carURL = json["viewItemURL"] as! String
carPrice = json["currentPrice"] as! String
}
}
I get the following error message:
Could not cast value of type '__NSSingleObjectArrayI' (0x10a2ec548) to 'NSString' (0x109729440).
I tried to access them like this:
"json["galleryURL"][0] as String!"
but I get the following error:
Type 'Any?' has no subscript members
The values look like this:
galleryURL = ("one value");
Do you guys know a way how to access them easily?
Thanks!
Just cast things to the appropriate types first. It sounds like your values are arrays containing a single string, so something like this:
var pictureURL: URL
required init?(json: [String: AnyObject]) {
guard let pictureURLString = (json["galleryURL"] as? [String])?.first,
let pictureURL = URLComponents(string: pictureURLString)?.url else {
return nil
}
self.pictureURL = pictureURL
}
Also, you may want to reconsider the types you're using for your properties. The pictureURL and carURL properties are URLs, so they make more sense typed as URL. The carPrice property is likely numeric, so it makes more sense as a Double.
I have some user comments stored in a database (parse-server) that I would like to would like to display on my viewController's viewDidLoad(). I can easily pull the comment objects as follows:
super.viewDidLoad()
func query(){
let commentsQuery = PFQuery(className: "Comments")
commentsQuery.whereKey("objectId", equalTo: detailDisclosureKey)
commentsQuery.findObjectsInBackground { (objectss, error) in
if let objects = objectss{
if objects.count == 1{
for object in objects{
self.unOrderedComments.append(object)
}
}
}
}
}
This query dumps all of the of the comments in the unOrederedComments array. Each comment is added to the database with a createdAt property automatically being added relating the exact time of its creation. This property is a string with (as an example) the form: "2017-08-13T19:31:47.776Z" (the Z at the end is at the end of every string... not exactly sure why its there but its constant). Now, each new comment is added in order to the top of database and thus any queried result should be in order regardless. However, I would like to make sure of this by reordering it if necessary. My general thought process is to use .sorted, but I cannot figure out how to apply this to my situation
func orderComments(unOrderComments: [PFObject]) -> [PFObject]{
let orderedEventComments = unOrderedEventComments.sorted(by: { (<#PFObject#>, <#PFObject#>) -> Bool in
//code
})
}
This is the generic set up but I cannot, despite looking up several examples online figure out what to put in the <#PFObject#>'s and in the //code. I want to order them based on the "createdAt" property but this is not achieved via dot notation and instead requires PFObject["createdAt"] and using this notation keeps leading to error. I feel as so though I may need to set up a custom predicate but I do not know how to do this.
I was in the same situation, what I did was to first create an array of structs with the data I downloaded where I turned the string createdAt into a Date, then used this function:
dataArrayOrdered = unOrderedArray.sorted(by: { $0.date.compare($1.date) == .orderedAscending})
(.date being the stored Date inside my array of strcuts)
Try this code, notice that I assumed you have a variable name called ["Comments"] inside your Parse database, so replace if necessary. Also, I realised that createdAt it's in Date format, so there was no need to change it from String to Date, chek if it works the same for you, if it doesn't refer to this: Swift convert string to date.
struct Comment {
var date = Date()
var comment = String()
}
var unOrderedComments: [Comment] = []
var orderedComments = [Comment]()
override func viewDidLoad() {
super.viewDidLoad()
query()
}
func query(){
let commentsQuery = PFQuery(className: "Comments")
commentsQuery.findObjectsInBackground { (objectss, error) in
if let objects = objectss{
if objects.count >= 1{
for object in objects{
let newElement = Comment(date: object.createdAt!, comment: object["Comments"] as! String)
self.unOrderedComments.append(newElement)
print(self.unOrderedComments)
}
}
self.orderedComments = self.unOrderedComments.sorted(by: { $0.date.compare($1.date) == .orderedAscending})
print(self.orderedComments)
}
}
}
I've got a server response returning
(
{
agreementId = "token.virtual.4321";
city = AMSTERDAM;
displayCommonName = "bunch-of-alphanumeric";
displaySoftwareVersion = "qb2/ene/2.7.14";
houseNumber = 22;
postalCode = zip;
street = "";
}
)
how do I get the value of agreementId? response['agreementId'] is not working. i've tried some example code with .first but I cannot get it working.
Some extra information, I do a http call to a server with alamofire. I try to parse the json to a constant response:
let response = JSON as! NSDictionary
However that returns a error message
Could not cast value of type '__NSSingleObjectArrayI' (0x1083600) to 'NSDictionary' (0x108386c).
So now parse the json to an array, which seems to be working. The code above is what
let response = JSON as! NSArry
print(response)
spits out.
Now I only need to retrieve the value from the key "agreementId" and I have no clue how to do that.
In swift you need to use Swift's native type Array/[] and Dictionary/[:] instead of NSArray and NSDictionary, if you specify the type like above means more specific then the compiler won't complain. Also use optional wrapping with if let or guard let to prevent crash.
if let array = JSON as? [[String:Any]] {//Swift type array of dictionary
if let dic = array.first {
let agreementId = dic["agreementId"] as? String ?? "N/A"//Set default value instead N/A
print(agreementId)
//access the other key-value same way
}
}
Note: If you having more than one object in your array then you need to simply loop through the array to access each dictionary of array.
if let array = JSON as? [[String:Any]] {//Swift type array of dictionary
for dic in array {
let agreementId = dic["agreementId"] as? String ?? "N/A"//Set default value instead N/A
print(agreementId)
//access the other key-value same way
}
}