I have an array of objects
{"total_rows":5,"offset":0,"rows":[
{"id":"index","key":"index","value":{"rev":"4-8655b9538706fc55e1c52c913908f338"}},
{"id":"newpage","key":"newpage","value":{"rev":"1-7a27fd343ff98672236996b3fe3abe4f"}},
{"id":"privacy","key":"privacy","value":{"rev":"2-534b0021f8ba81d09ad01fc32938ce15"}},
{"id":"secondpage","key":"secondpage","value":{"rev":"2-65847da61d220f8fc128a1a2f1e21e89"}},
{"id":"third page","key":"third page","value":{"rev":"1-d3be434b0d3157d7023fca072e596fd3"}}
]}
that I need too fit in struct and then decode in swift. My current code is:
struct Index: Content {
var total_rows: Int
var offset: Int
// var rows: [String: String] // I don't really know what I am doing here
}
and the router (using vapor)
router.get("/all") { req -> Future<View> in
let docId = "_all_docs"
print(docId)
let couchResponse = couchDBClient.get(dbName: "pages", uri: docId, worker: req)
guard couchResponse != nil else {
throw Abort(.notFound)
}
print("one")
return couchResponse!.flatMap { (response) -> EventLoopFuture<View> in
guard let data = response.body.data else { throw Abort(.notFound) }
print(data)
let decoder = JSONDecoder()
let doc = try decoder.decode(Index.self, from: data)
let allDocs = Index(
total_rows: doc.total_rows,
offset: doc.offset
//rows: doc.rows
)
print("test after allDocs")
return try req.view().render("index", allDocs)
}
}
to summarise all is fine for the first level (total rows and offset are int and properly decoded) but how can I include in my structure the rows: array and assign thee parsed values to it ?
You're on the right road, you just need to keep going.
struct Index: Decodable {
var total_rows: Int
var offset: Int
var rows: [Row]
}
Then you define a Row:
struct Row: Decodable {
var id: String
var key: String
var value: Value
}
It's not really clear what a Value is in this context, but just to keep the structure.
struct Value: Decodable {
var rev: String
}
And that's all.
let index = try JSONDecoder().decode(Index.self, from: jsonData)
Related
Weird. I swear this was working but then it just stopped working .. or ... Please ignore the i+i ,I will clean this up...
I don't have a clue why but myrecords?[i].title is returning nil. The json.releases[i].date_adde is working fine and full of data. I can "print" it and get a result. but when I go to copy it to the myrecords it is returning nil.
I download the data from JSON, that works fine. then I try to copy the data to a struc array I can get to in other parts of my app and now my myrecords data is empty. what the heck am I doing wrong?
import Foundation
var numberOfRecords : Int = 0
struct routine {
var dateadded : String
var title : String
var artist : String
var year : Int
var recordlabel : String
}
var myrecords: [routine]?
//-------------------------------------------------------------
struct Response: Codable {
var pagination: MyResult
var releases: [MyReleases]
}
public struct MyResult: Codable {
var page: Int
var per_page: Int
var items: Int
}
public struct MyReleases: Codable {
var date_added: String
var basic_information: BasicInformation
}
public struct BasicInformation: Codable {
var title: String
var year: Int
var artists : [Artist]
var labels: [Label]
}
public struct Artist: Codable {
var name: String
}
public struct Label: Codable {
var name: String
}
let url = "https://api.discogs.com/users/douglasbrown/collection/folders/0/releases?callback=&sort=added&sort_order=desc&per_page=1000"
public func getData(from url: String) {
let task = URLSession.shared.dataTask(with: URL(string: url)!, completionHandler: { data, response, error in
guard let data = data, error == nil else {
print("something went wrong")
return
}
//HAVE DATA
var result: Response?
do {
result = try JSONDecoder().decode(Response.self, from: data)
}
catch {
print("Converion Error:\(error.localizedDescription)")
}
guard let json = result else {
return
}
numberOfRecords = json.pagination.items
var i: Int
i = -1
for _ in json.releases {
i = i + 1
myrecords?[i].dateadded = json.releases[i].date_added
myrecords?[i].title = json.releases[i].basic_information.title
myrecords?[i].artist = json.releases[i].basic_information.artists[0].name
myrecords?[i].year = json.releases[i].basic_information.year
myrecords?[i].recordlabel = json.releases[i].basic_information.labels[0].name
print(">>>>>>\(myrecords?[i].dateadded)")
}
})
task.resume()
}
You haven't initialized myrecords array.
Otherwise, you cannot use subscript like myrecords[i] when you don't know the capacity of array, it can be out of index.
First, initialize your array.
var myrecords: [routine]? = []
Second, append new element to array instead of using subscript
for _ in json.releases {
let newRecord = routine()
newRecord.dateadded = json.releases[i].date_added
newRecord.title = json.releases[i].basic_information.title
newRecord.artist = json.releases[i].basic_information.artists[0].name
newRecord.year = json.releases[i].basic_information.year
newRecord.recordlabel = json.releases[i].basic_information.labels[0].name
myrecords.append(newRecord)
}
This is the answer. :) THANK YOU All for pointing me in the right direction
struct Routine {
var dateadded : String
var title : String
var artist : String
var year : Int
var recordlabel : String
}
var myRecords: [Routine] = []
var i : Int
i = -1
for _ in json.releases {
var newRecord = Routine.self(dateadded: "", title: "", artist: "", year: 0, recordlabel: "")
i = i + 1
newRecord.dateadded = json.releases[i].date_added
newRecord.title = json.releases[i].basic_information.title
newRecord.artist = json.releases[i].basic_information.artists[0].name
newRecord.year = json.releases[i].basic_information.year
newRecord.recordlabel = json.releases[i].basic_information.labels[0].name
myRecords.append(newRecord)
}
print(">>>>\(myRecords[0].dateadded)")
I will clean up the bad code too but it works and that is good! :)
I've two Models, Trip and Location. I would return a custom response with some field of trip and the number of Location that has the tripID equal to id of Trip. There is my code(not working). The field locationCount is always empty.
func getList(_ request: Request)throws -> Future<Response> {
let deviceIdReq = request.parameters.values[0].value
let queryTrips = Trip.query(on: request).filter(\.deviceId == deviceIdReq).all()
var tripsR = [TripCustomContent]()
var trips = [Trip]()
return queryTrips.flatMap { (result) -> (Future<Response>) in
trips = result
var count = 0
for t in trips {
let tripIdString = String(t.id!)
let v = Location.query(on: request).filter(\.tripID == tripIdString).count().map({ (res) -> Int in
return res
})/*.map{ (result) -> (Int) in
count = result
return result
}*/
let tripCustomContent = TripCustomContent.init(startTimestamp: t.startTimestamp, endTimestamp: t.endTimestamp, deviceId: t.deviceId, locationCount: v)
tripsR.append(tripCustomContent)
}
let jsonEncoder = JSONEncoder()
let data = try jsonEncoder.encode(tripsR)
let response = HTTPResponse.init(status: .ok, version: HTTPVersion.init(major: x, minor: y), headers: HTTPHeaders.init(), body: data)
let finalResponse = Response.init(http: response, using: request)
return try g.encode(for: request)
}
}
and this is my custom content struct:
struct TripCustomContent: Encodable {
var startTimestamp: String?
var endTimestamp: String?
var deviceId: String
var locationCount: Future<Int>
}
any suggestions?
You're trying to use a value which isn't available yet. When you're returning a Future, you aren't returning the value inside it.
So you want your TripCustomContent to be like this (use in vapor Content instead of Codable:
struct TripCustomContent: Content {
var startTimestamp: String?
var endTimestamp: String?
var deviceId: String
var locationCount: Int
}
You queried the Trip correctly, but not the Location. You could maybe try something like this:
return queryTrips.flatMap { trips -> Future<[TripCustomContent]> in
let tripIds = trips.map({ String($0.id!) })
return Location.query(on: request).filter(\.tripID ~~ tripIds).all().map { locations in
return trips.map { trip in
let locationCount = locations.filter({ $0.tripId == String(trip.id!) }).count
return TripCustomContent(... locationCount: locationCount)
}
}
}
What did I do here?
Map the trips to their tripIds to get an array of tripIds
Get all locations with a tripId of one of the tripIds in the above array
Map each of the trips to an instance of TripCustomContent, using the locations of the database filtered by tripId
Finally, you don't need to encode the JSON yourself, just return objects conforming Content:
func getList(_ request: Request) throws -> Future<[TripCustomContent]>
The above could be a solution to your strategy. But maybe you take a look at relations if they can be a more efficient, easier and faster way.
I am trying to convert Realm Object into JSON. My version is working but not if you want to put multiple objects into JSON. So my question is, how should you add multiple Realm Objects into JSON?
Something like that:
{
"Users": [
{"id": "1","name": "John"},{"id": "2","name": "John2"},{"id": "3","name": "John3"}
],
"Posts": [
{"id": "1","title": "hey"},{"id": "2","title": "hey2"},{"id": "3","title": "hey3"}
]
}
This is what I am doing right now:
func getRealmJSON(name: String, realmObject: Object, realmType: Any) -> String {
do {
let realm = try Realm()
let table = realm.objects(realmType as! Object.Type)
if table.count == 0 {return "Empty Table"}
let mirrored_object = Mirror(reflecting: realmObject)
var properties = [String]()
for (_, attr) in mirrored_object.children.enumerated() {
if let property_name = attr.label as String! {
properties.append(property_name)
}
}
var jsonObject = "{\"\(name)\": ["
for i in 1...table.count {
var str = "{"
var insideStr = String()
for property in properties {
let filteredTable = table.value(forKey: property) as! [Any]
insideStr += "\"\(property)\": \"\(filteredTable[i - 1])\","
}
let index = insideStr.characters.index(insideStr.startIndex, offsetBy: (insideStr.count - 2))
insideStr = String(insideStr[...index])
str += "\(insideStr)},"
jsonObject.append(str)
}
let index = jsonObject.characters.index(jsonObject.startIndex, offsetBy: (jsonObject.count - 2))
jsonObject = "\(String(jsonObject[...index]))]}"
return jsonObject
}catch let error { print("\(error)") }
return "Problem reading Realm"
}
Above function does like that, which is good for only one object:
{"Users": [{"id": "1","name": "John"},{"id": "2","name": "John2"},{"id": "3","name": "John3"}]}
Like this I call it out:
let users = getRealmJSON(name: "Users", realmObject: Users(), realmType: Users.self)
let posts = getRealmJSON(name: "Posts", realmObject: Posts(), realmType: Posts.self)
And I tried to attach them.
Can anybody please lead me to the right track?
You can use data models to encode/decode your db data:
For example you have
class UserEntity: Object {
#objc dynamic var id: String = ""
#objc dynamic var createdAt: Date = Date()
#objc private dynamic var addressEntities = List<AddressEntity>()
var addresses: [Address] {
get {
return addressEntities.map { Address(entity: $0) }
}
set {
addressEntities.removeAll()
let newEntities = newValue.map { AddressEntity(address: $0) }
addressEntities.append(objectsIn: newEntities)
}
}
}
Here you hide addressEntities with private and declare addresses var with Address struct type to map entities into proper values;
And then use
struct User: Codable {
let id: String
let createdAt: Date
let addresses: [Address]
}
And then encode User struct any way you want
Say I have a struct Coin
struct Coin {
var value: Float?
var country: String?
var color: String?
}
I have two instances of a Coin; we'll call them coinA and coinB.
let coinA = Coin()
coinA.value = nil
coinA.country = "USA"
coinA.color = "silver"
let coinB = Coin()
coinB.value = 50.0
Now, I want to merge the values of coinB into coinA. So the result would be coinA whose values would result in:
country = "USA"
color = "silver"
value = 50.0
I am able to accomplish this with Dictionary objects using the merge() function. However, I am unsure how to accomplish this using custom Swift objects. Is there a way?
Update
Here's how I've gotten it to work with dictionaries:
var originalDict = ["A": 1, "B": 2]
var newDict = ["B": 69, "C": 3]
originalDict.merge(newDict) { (_, new) in new }
//originalDict = ["A": 1, "B": 69, "C": 3]
And I will further clarify, in this function if the newDict does not have keys that the originalDict, the originalDict maintains them.
Ultimately, the most efficient way in the fewest lines of code is probably exactly what you'd expect:
extension Coin {
func merge(with: Coin) -> Coin {
var new = Coin()
new.value = value ?? with.value
new.country = country ?? with.country
new.color = color ?? with.color
return new
}
}
let coinC = coinA.merge(with: coinB)
Note that in the above scenario, the resulting value will always be coinA's, and will only be coinB's if coinA's value for a given key is nil. Whenever you change, add, or delete a property on Coin, you'll have to update this method, too. However, if you care more about future-proofing against property changes and don't care as much about writing more code and juggling data around into different types, you could have some fun with Codable:
struct Coin: Codable {
var value: Float?
var country: String?
var color: String?
func merge(with: Coin, uniquingKeysWith conflictResolver: (Any, Any) throws -> Any) throws -> Coin {
let encoder = JSONEncoder()
let selfData = try encoder.encode(self)
let withData = try encoder.encode(with)
var selfDict = try JSONSerialization.jsonObject(with: selfData) as! [String: Any]
let withDict = try JSONSerialization.jsonObject(with: withData) as! [String: Any]
try selfDict.merge(withDict, uniquingKeysWith: conflictResolver)
let final = try JSONSerialization.data(withJSONObject: selfDict)
return try JSONDecoder().decode(Coin.self, from: final)
}
}
With that solution, you can call merge on your struct like you would any dictionary, though note that it returns a new instance of Coin instead of mutating the current one:
let coinC = try coinA.merge(with: coinB) { (_, b) in b }
I thought it would be interesting to show a solution based on Swift key paths. This allows us to loop somewhat agnostically through the properties — that is, we do not have to hard-code their names in a series of successive statements:
struct Coin {
var value: Float?
var country: String?
var color: String?
}
let c1 = Coin(value:20, country:nil, color:"red")
let c2 = Coin(value:nil, country:"Uganda", color:nil)
var c3 = Coin(value:nil, country:nil, color:nil)
// ok, here we go
let arr = [\Coin.value, \Coin.country, \Coin.color]
for k in arr {
if let kk = k as? WritableKeyPath<Coin, Optional<Float>> {
c3[keyPath:kk] = c1[keyPath:kk] ?? c2[keyPath:kk]
} else if let kk = k as? WritableKeyPath<Coin, Optional<String>> {
c3[keyPath:kk] = c1[keyPath:kk] ?? c2[keyPath:kk]
}
}
print(c3) // Coin(value: Optional(20.0), country: Optional("Uganda"), color: Optional("red"))
There are unfortunate features of key paths that require us to cast down from the array element explicitly to any possible real key path type, but it still has a certain elegance.
If you're willing to make the merge function specific to Coin, you can just use the coalesce operator like so:
struct Coin {
var value: Float?
var country: String?
var color: String?
func merge(_ other: Coin) -> Coin {
return Coin(value: other.value ?? self.value, country: other.country ?? self.country, color: other.color ?? self.color)
}
}
let coinC = coinA.merge(coinB)
This will return a new Coin using the values from coinB, and filling in any nils with those from coinA.
If your goal is to change coin A what you need is a mutating method. Note that structures are not like classes. If you would like to change its properties you need to declare your coin as variable. Note that none of your examples would compile if you declare your coins as constants:
struct Coin {
var value: Float?
var country: String?
var color: String?
mutating func merge(_ coin: Coin) {
value = value ?? coin.value
country = country ?? coin.country
color = color ?? coin.color
}
init(value: Float? = nil, country: String? = nil, color: String? = nil) {
self.value = value
self.country = country
self.color = color
}
}
Playground testing:
var coinA = Coin(country: "USA", color: "silver")
coinA.merge(Coin(value: 50))
print(coinA.country ?? "nil") // "USA"
print(coinA.color ?? "nil") // "silver"
print(coinA.value ?? "nil") // 50.0
This is not a high-level approach like the merge one you shared the link to but as long as you have a struct to implement the merge feature into, it will do the job.
func merge(other: Coin, keepTracksOfCurrentOnConflict: Bool) -> Coin {
var decidedValue = value
if decidedValue == nil && other.value != nil {
decidedValue = other.value
} else if other.value != nil {
//in this case, it's conflict.
if keepTracksOfCurrentOnConflict {
decidedValue = value
} else {
decidedValue = other.value
}
}
var resultCoin = Coin(value: decidedValue, country: nil, color: nil)
return resultCoin
}
}
You can do the same for other properties.
If you want to wrap it around protocol. The idea behind is the same:
you convert object's to dict
merge two dict's
convert merged dict back to your object
import Foundation
protocol Merge: Codable {
}
extension Dictionary where Key == String, Value == Any {
func mergeAndReplaceWith(object: [Key: Value]) -> [Key: Value] {
var origin = self
origin.merge(object) { (_, new) in
new
}
return origin
}
}
extension Merge {
func toJson() -> [String: Any] {
let jsonData = try! JSONEncoder().encode(self)
let json = try! JSONSerialization.jsonObject(with: jsonData, options: []) as! [String: Any]
return json
}
func merge(object: Merge) -> Merge {
let origin = self.toJson()
let objJson = object.toJson()
let decoder = JSONDecoder()
let merge = origin.mergeAndReplaceWith(object: objJson)
var jsonData = try! JSONSerialization.data(withJSONObject: merge, options: .prettyPrinted)
var mergedObject = try! decoder.decode(Self.self, from: jsonData)
return mergedObject
}
}
struct List: Merge {
let a: String
}
struct Detail: Merge {
struct C: Codable {
let c: String
}
let a: String
let c: C?
}
let list = List(a: "a_list")
let detail_without_c = Detail(a: "a_detail_without_c", c: nil)
let detail = Detail(a: "a_detail", c: Detail.C(c: "val_c_0"))
print(detail.merge(object: list))
print(detail_without_c.merge(object: detail))
Detail(a: "a_list", c: Optional(__lldb_expr_5.Detail.C(c: "val_c_0")))
Detail(a: "a_detail", c: Optional(__lldb_expr_5.Detail.C(c: "val_c_0")))
With this solution you can actually merge two representations of your endpoint, in my case it is List and Detail.
struct Response: Codable {
let status: String
let value: [Value]
}
struct Value: Codable {
let psid: Int
let name: String
let valute: String
let reserve: Double
let with_codes: Int
let img: String
}
var good = [Value]()//first array
struct Response1: Codable {
let status: String
let value: [Value1]
}
struct Value1: Codable {
let id: String
let enabled: Int
let direct: Int
let psid1: Int
let psid2: Int
let in: Int
let in_valute: String
let out: Double
let out_valute: String
let in_min: Double
let in_max: Int
let reserve: Double
}
var good1 = [Value1]()//second array
good.forEach { goodItem in
if good1.contains(where: { good1Item -> Bool in
return good1Item.psid2 == goodItem.psid
}) {
print(goodItem)
}
}
The problem is that when I need to output goodItem.name to a table, only the last value is output, although when I check everything in the console, google I found that the return method returns only the last value, how can I fix it?
This worked for me:
for value in good {
if good1.filter( {$0.psid2 == value.psid}).count > 0 {
print(value.name)
}
}