I have a dictionary from type [String: Any] that looks like this
"arExtensions" : {
"images" : {
"-LmgO2yG_TWbfOM4Y8X3" : {
"imagePath" : "https://firebasestorage.googleapis.com/v0/b/gpk-citycards.appspot.com/o/ARResources%2F78E88F6D-52F0-43A3-B585-9760D19F0B81?alt=media&token=be3a664f-a94b-4ead-bea4-1197155c016e",
"position" : "bottom"
},
"-LmgO4qaMKupHZIAEoLk" : {
"imagePath" : "https://firebasestorage.googleapis.com/v0/b/gpk-citycards.appspot.com/o/ARResources%2FC7303CF9-0E86-4DC6-A5F5-2761537F0A30?alt=media&token=1f928774-8221-474b-881e-7f395e439131",
"position" : "rightMiddle"
},
"-LmgO9vLT8rEx9Ndog4S" : {
"imagePath" : "https://firebasestorage.googleapis.com/v0/b/gpk-citycards.appspot.com/o/ARResources%2F9132B5B6-E904-4BCE-B56A-0271CB901A7D?alt=media&token=bd66cd1d-494b-4a82-8d74-6e00ac8c8ae6",
"position" : "leftMiddle"
}
}
}
I want to add the images into an object.
var imageObjects: [ImageObject] = []
I know that I can get the values with the keys like this
let dictImages: [String: Any] = dictArExtensions["images"] as! [String : Any]
unfortunately I don't know the key of the children of images.
with two iteration, first to get the key, second to get the needed values i solved the problem like this
var imageKeys: [String] = []
for dict in dictImages{
print(dict.key)
imageKeys.append(dict.key)
print(dict.value)
}
for keys in imageKeys{
let dictImage: [String: Any] = dictImages[keys] as! [String : Any]
let imagePath = dictImage["imagePath"] as? String
let position = dictImage["position"] as? String
imageObjects.append(ImageObject(imagePath: imagePath!, position: position!))
}
but, it seems like a bad solution.
Is there a better or rather more professional solution to this?
You can enumerate the dictionary very simply with key and value but the key is actually unused.
And if you declare the child dictionary as [String:String] you can get rid of the type cast
for (_, value) in dictImages {
let dictImage = value as! [String:String]
let imagePath = dictImage["imagePath"]
let position = dictImage["position"]
imageObjects.append(ImageObject(imagePath: imagePath!, position: position!))
}
Please read the section about dictionaries in the Language Guide
I'm porting an android app and using firebase in android it is possible to save a format in this way.
How can i do this on Swift? I read that i can store only this kind of data
NSString
NSNumber
NSDictionary
NSArray
How can I store the obj in atomic operation?
It's correct to store every field of the user object in separate action?
Firebase on Android
mDatabaseReferences.child("users").child(user.getUuid()).setValue(user)
I generally store objects as dictionaries on firebase. If, within my application, I have a User object, and it has properties as such:
class User {
var username = ""
var email = ""
var userID = ""
var consecutiveDaysLoggedOn = Int()
}
let newUser = User()
newUser.username = "LeviYoder"
newUser.email = "LeviYoder#LeviYoder.com"
newUser.userID = "L735F802847A-"
newUser.consecutiveDaysLoggedOn = 1
I would just store those properties as a dictionary, and write that dictionary to my firebase database:
let userInfoDictionary = ["username" : newUser.username
"email" : newUser.email
"userID" : newUser.userID
"consecutiveDaysLoggedOn" : newUser.consecutiveDaysLoggedOn]
let ref = Database.database().reference.child("UserInfo").child("SpecificUserFolder")
// ref.setValue(userInfoDictionary) { (error:Error?, ref:DatabaseReference) in
ref.setValue(userInfoDictionary, withCompletionBlock: { err, ref in
if let error = err {
print("userInfoDictionary was not saved: \(error.localizedDescription)")
} else {
print("userInfoDictionary saved successfully!")
}
}
Does that address your question?
I come with a little extension used to convert a standard SwiftObject in readable dictionnary for FireStore:
extension Encodable {
var toDictionnary: [String : Any]? {
guard let data = try? JSONEncoder().encode(self) else {
return nil
}
return try? JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String: Any]
}
}
For example, in my model:
struct Order: Encodable {
let symbol: String
let shares: Int
let price: Float
let userID: String
}
Called with this line:
let dictionnary = order.toDictionnary
This is the kind of dictionary generated
4 elements
▿ 0 : 2 elements
- key : "symbol"
- value : FP.PAR
▿ 1 : 2 elements
- key : "shares"
- value : 10
▿ 2 : 2 elements
- key : "userID"
- value : fake_id
▿ 3 : 2 elements
- key : "price"
- value : 100
Use
self.ref.child("users").child(user.uid).setValue(["username": username])
I am converting objective c code in swift.
I am getting data from server which has a dictionaries in a dictionaries.
i am getting key value string but cannot get dictionary.
example data:
data = {
caption = hello;
image = {
a = "https://www.google.com/1024x1024";
b = "https://www.google.com/640x640";
c = "https://www.google.com/480x480";
d = "https://www.google.com/";
};
};
i can get caption
let dataDict = (mainDict[data] as? Dictionary<String,AnyObject>)!
Obj.caption=String(dataDict["caption"]!) //getting hello
Obj.imageDictionary = (dataDict["image"] as? Dictionary<String,String>)! //getting 0 key value pairs
initialised imageDictionary as
var imageDictionary = Dictionary<String, String>()
please suggest how to get the image dictionary, I want this dictionary to store in imageDictionary object.
Any suggestions would be highly appreciated!
Thanks in advance!
Try this:
let data : [String : Any] = ["caption" : "hello",
"image" :["a" : "https://www.google.com/1024x1024",
"b" : "https://www.google.com/640x640",
"c" : "https://www.google.com/480x480",
"d" : "https://www.google.com/",
]
]
let caption = data["caption"] as! String
let imageDictionary = data["image"] as! [String : String]
In imageDictionary, I am getting:
["b": "https://www.google.com/640x640", "a": "https://www.google.com/1024x1024", "d": "https://www.google.com/", "c": "https://www.google.com/480x480"]
Screenshot:
I have this function that fetch users from FireBase and convert them in Dictionary:
let leaderBoardDB = FIRDatabase.database().reference().child("scores1").queryOrderedByValue().queryLimited(toLast: 5)
leaderBoardDB.observe( .value, with: { (snapshot) in
print("scores scores", snapshot)
if let dictionary = snapshot.value as? [String: Any] {
for playa in dictionary {
let player = Player()
print("plaaaaayyyyyaaaaa", playa)
print("plaaaaayyyyyaaaaa key", playa.key)
print("plaaaaayyyyyaaaaa.value", playa.value)
player.id = playa.key
print(playa.key["name"])
}
}
}, withCancel: nil)
}
and I get this result:
plaaaaayyyyyaaaaa ("inovoID", {
name = Tatiana;
points = 6; }) plaaaaayyyyyaaaaa key inovoID plaaaaayyyyyaaaaa.value {
name = Tatiana;
points = 6; } aaaa i id Optional("inovoID")
the problem is that i can't obtain the name and the points of the user. when i try it with:
print(playa.key["name"])
it gaves me this error:
Cannot subscript a value of type 'String' with an index of type 'String'
can anyone help me with this, please?
Since your JSON is
"inovoID" : { "name" : "Tatiana", "points" : 6 }
playa.key is "inovoID"
playa.value is { "name" : "Tatiana", "points" : 6 }
The key is String and cannot be subscripted. That's what the error says.
You need to subscribe the value and safely cast the type to help the compiler.
if let person = playa.value as? [String:Any] {
print(person["name"] as! String)
}
I think you're looking for:
player.name = dictionary["name"] as? String
You don't need to iterate through the dictionary to access it's values. If you're looking for the value of a key, just get it.
I have a simple Dictionary which is defined like:
var dict : NSDictionary = [ 1 : "abc", 2 : "cde"]
Now I want to add an element into this dictionary: 3 : "efg"
How can I append 3 : "efg" into this existing dictionary?
You're using NSDictionary. Unless you explicitly need it to be that type for some reason, I recommend using a Swift dictionary.
You can pass a Swift dictionary to any function expecting NSDictionary without any extra work, because Dictionary<> and NSDictionary seamlessly bridge to each other. The advantage of the native Swift way is that the dictionary uses generic types, so if you define it with Int as the key and String as the value, you cannot mistakenly use keys and values of different types. (The compiler checks the types on your behalf.)
Based on what I see in your code, your dictionary uses Int as the key and String as the value. To create an instance and add an item at a later time you can use this code:
var dict = [1: "abc", 2: "cde"] // dict is of type Dictionary<Int, String>
dict[3] = "efg"
If you later need to assign it to a variable of NSDictionary type, just do an explicit cast:
let nsDict = dict as! NSDictionary
And, as mentioned earlier, if you want to pass it to a function expecting NSDictionary, pass it as-is without any cast or conversion.
you can add using the following way and change Dictionary to NSMutableDictionary
dict["key"] = "value"
I know this might be coming very late, but it may prove useful to someone.
So for appending key value pairs to dictionaries in swift, you can use updateValue(value: , forKey: ) method as follows :
var dict = [ 1 : "abc", 2 : "cde"]
dict.updateValue("efg", forKey: 3)
print(dict)
SWIFT 3 - XCODE 8.1
var dictionary = [Int:String]()
dictionary.updateValue(value: "Hola", forKey: 1)
dictionary.updateValue(value: "Hello", forKey: 2)
dictionary.updateValue(value: "Aloha", forKey: 3)
So, your dictionary contains:
dictionary[1: Hola, 2: Hello, 3: Aloha]
If your dictionary is Int to String you can do simply:
dict[3] = "efg"
If you mean adding elements to the value of the dictionary a possible solution:
var dict = Dictionary<String, Array<Int>>()
dict["key"]! += [1]
dict["key"]!.append(1)
dict["key"]?.append(1)
Swift 3+
Example to assign new values to Dictionary. You need to declare it as NSMutableDictionary:
var myDictionary: NSMutableDictionary = [:]
let newValue = 1
myDictionary["newKey"] = newValue
print(myDictionary)
For whoever reading this for swift 5.1+
// 1. Using updateValue to update the given key or add new if doesn't exist
var dictionary = [Int:String]()
dictionary.updateValue("egf", forKey: 3)
// 2. Using a dictionary[key]
var dictionary = [Int:String]()
dictionary[key] = "value"
// 3. Using subscript and mutating append for the value
var dictionary = [Int:[String]]()
dictionary[key, default: ["val"]].append("value")
In Swift, if you are using NSDictionary, you can use setValue:
dict.setValue("value", forKey: "key")
Given two dictionaries as below:
var dic1 = ["a": 1, "c": 2]
var dic2 = ["e": 3, "f": 4]
Here is how you can add all the items from dic2 to dic1:
dic2.forEach {
dic1[$0.key] = $0.value
}
Dict.updateValue updates value for existing key from dictionary or adds new new key-value pair if key does not exists.
Example-
var caseStatusParams: [String: AnyObject] = ["userId" : UserDefault.userID ]
caseStatusParams.updateValue("Hello" as AnyObject, forKey: "otherNotes")
Result-
▿ : 2 elements
- key : "userId"
- value : 866
▿ : 2 elements
- key : "otherNotes"
- value : "Hello"
[String:Any]
For the fellows using [String:Any] instead of Dictionary below is the extension
extension Dictionary where Key == String, Value == Any {
mutating func append(anotherDict:[String:Any]) {
for (key, value) in anotherDict {
self.updateValue(value, forKey: key)
}
}
}
As of Swift 5, the following code collection works.
// main dict to start with
var myDict : Dictionary = [ 1 : "abc", 2 : "cde"]
// dict(s) to be added to main dict
let myDictToMergeWith : Dictionary = [ 5 : "l m n"]
let myDictUpdated : Dictionary = [ 5 : "lmn"]
let myDictToBeMapped : Dictionary = [ 6 : "opq"]
myDict[3]="fgh"
myDict.updateValue("ijk", forKey: 4)
myDict.merge(myDictToMergeWith){(current, _) in current}
print(myDict)
myDict.merge(myDictUpdated){(_, new) in new}
print(myDict)
myDictToBeMapped.map {
myDict[$0.0] = $0.1
}
print(myDict)
To add new elements just set:
listParameters["your parameter"] = value
There is no function to append the data in dictionary. You just assign the value against new key in existing dictionary. it will automatically add value to the dictionary.
var param = ["Name":"Aloha","user" : "Aloha 2"]
param["questions"] = "Are you mine?"
print(param)
The output will be like
["Name":"Aloha","user" : "Aloha 2","questions" : ""Are you mine"?"]
To append a new key-value pair to a dictionary you simply have to set the value for the key. for eg.
// Initialize the Dictionary
var dict = ["name": "John", "surname": "Doe"]
// Add a new key with a value
dict["email"] = "john.doe#email.com"
print(dict)
Output -> ["surname": "Doe", "name": "John", "email": "john.doe#email.com"]
var dict = ["name": "Samira", "surname": "Sami"]
// Add a new enter code herekey with a value
dict["email"] = "sample#email.com"
print(dict)
Up till now the best way I have found to append data to a dictionary by using one of the higher order functions of Swift i.e. "reduce". Follow below code snippet:
newDictionary = oldDictionary.reduce(*newDictionary*) { r, e in var r = r; r[e.0] = e.1; return r }
#Dharmesh In your case, it will be,
newDictionary = dict.reduce([3 : "efg"]) { r, e in var r = r; r[e.0] = e.1; return r }
Please let me know if you find any issues in using above syntax.
Swift 5 happy coding
var tempDicData = NSMutableDictionary()
for temp in answerList {
tempDicData.setValue("your value", forKey: "your key")
}
I added Dictionary extension
extension Dictionary {
func cloneWith(_ dict: [Key: Value]) -> [Key: Value] {
var result = self
dict.forEach { key, value in result[key] = value }
return result
}
}
you can use cloneWith like this
newDictionary = dict.reduce([3 : "efg"]) { r, e in r.cloneWith(e) }
if you want to modify or update NSDictionary then
first of all typecast it as NSMutableDictionary
let newdictionary = NSDictionary as NSMutableDictionary
then simply use
newdictionary.setValue(value: AnyObject?, forKey: String)