This is my JSON data, how can I get src data in 0 in pickArray?
"pickArray" : "{\"0\":{\"src\":\"https:\/\/fb-s-d-a.akamaihd.net\/h-ak-xpl1\/v\/t1.0-9\/p720x720\/18010403_1525007564199498_8009700960533638318_n.png?oh=25dbc9c1522dcfdd1d15cdd3e8c0c7da&oe=59997685&__gda__=1502470695_f212ade003e9b1c4ddc6a3ab6cc9e7e7\",\"width\":720,\"height\":720}}"
If I do it like this:
let dataArray = json["pickArray"]
print("dataArray = ",dataArray)
dataArray = {"0":{"src":"https://fb-s-d-a.akamaihd.net/h-ak-xpl1/v/t1.0-9/p720x720/18010403_1525007564199498_8009700960533638318_n.png?oh=25dbc9c1522dcfdd1d15cdd3e8c0c7da&oe=59997685&__gda__=1502470695_f212ade003e9b1c4ddc6a3ab6cc9e7e7","width":720,"height":720}}
But if I do it like this, show null:
let srcArray = dataArray["0"]
print("srcArray = ",srcArray)
I'm using swift3.0
Its looks like that with key pickArray you are having JSON response in String so get that string and convert it data and get JSON from it and then get src from it.
let stringResponse = json["pickArray"].stringValue
if let data = stringResponse.data(using: .utf8) {
let pickArray = JSON(data: data)
//Now access the pickArray to get the src
var sortedKeys = [String]()
if let allKeys = pickArray.dictionaryObject {
sortedKeys = Array(allKeys.keys).sorted { $0.compare($1, options: .numeric) == .orderedAscending }
}
for key in sortedKeys {
print(pickArray[key]["src"].stringValue)
print(pickArray[key]["width"].intValue)
print(pickArray[key]["height"].intValue)
}
}
let srcArray = dataArray["0"].dictionaryObject!
print("srcArray = \(srcArray)")
Now you can access element of "0" value as like below. Hope this work for you.
let jsonScr = JSON(srcArray)
let srcURL = jsonScr["scr"].stringValue
Related
I am reading in a text file of translation pairs of this format:
boy:garçon
garçon:boy
Into an array using the following code:
var vocab:[String:String] = [:]
let path = Bundle.main.path(forResource: "words_alpha", ofType: "txt")!
let text = try! String(contentsOfFile: path, encoding: String.Encoding.utf8)
let vocab = text.components(separatedBy: CharacterSet.newlines)
The imported array looks like this:
["boy:garçon", "garçon:boy"]
Whereas I would like the array to be formatted like this:
["boy":"garçon", "garçon":"boy"]
What is the best way to achieve the desired array format shown above using a Swift string transformation?
Have been trying to use .split, but with not much success.
Let's be clear:
["boy":"garçon", "garçon":"boy"]
That's a Dictionary, not an Array.
There a multiples ways to do that, here's two possible codes:
var manual: [String: String] = [:]
array.forEach { aString in
let components = aString.components(separatedBy: ":")
guard components.count == 2 else { return }
manual[components[0]] = components[1]
}
print(manual)
or
let reduced = array.reduce(into: [String: String]()) { result, current in
let components = current.components(separatedBy: ":")
guard components.count == 2 else { return }
result[components[0]] = components[1]
}
print(reduced)
Output (for both):
$> ["garçon": "boy", "boy": "garçon"]
As said, it's a Dictionary, so there is no guarantee that the print be:
["garçon": "boy", "boy": "garçon"] or ["boy":"garçon", "garçon":"boy"], it's key-value access, not index-value access.
Please help me understand the logic reading data from the Firestore document, if one of the values is an array. I tried other answers here and sources but never came to a simple working way and understand clearly. Firestore document structure — example. And Swift class targets for saving (conditional):
struct MyStruct {
var name: String
var pages: Int
}
let part1 = [MyStruct]()
let name1 = ""
let pages1 = 0
let part2 = [MyStruct]()
let name2 = ""
let pages2 = 0
func readFirestore() { }
What should the document reader function look like to add data to existing targets in the class? Thanks in advance for any help in improving my understanding!
They helped to deal with familiar, thank you for what they are. As expected, everything is simple. But for the beginner there is nothing more difficult than simplicity 😁
func readFirestore() {
self.db.collection("example").document("book").getDocument { (document, error) in
if error == nil {
if document != nil && document!.exists {
//get all document data
guard let documentData = document!.data() else {return}
//get value-array for key "part1"
let element = documentData["part1"] as? [Any] //print -> Optional([name1, 100])
//get first element in array
guard let nameDB = element?[0] as? String else {return} //print -> name1
guard let pagesDB = element?[1] as? String else {return} //print -> 100
//append in class
part1.append(MyStruct(name: nameDB, pages: pagesDB))
name1 = nameDB
pages1 = pagesDB
}
}
}
}
I have a CoreData entity Transaction with a decimal amount attribute. I want to get the sum of all amounts filtered by a predicate.
Altohugh there are solutions using loops I want to do it directly in CoreData because of performance (and understanding NSExpression).
The following code works as expected but, as I said, is not what I am looking for
// Easy way: Fetch all and use `value(forKeyPath:)`
let transactionFetch = NSFetchRequest<NSManagedObject>(entityName: CoreDateWrapper.Entity.Transaction)
var results: [NSManagedObject] = []
do {
results = try wrapper.context.fetch(transactionFetch)
} catch {
print("Error: \(error.localizedDescription)")
}
print((results as NSArray).value(forKeyPath: "#sum.\(CoreDateWrapper.Attribute.amount)") as! Decimal)
Now I want to use NSExpression, but the fetch result always is an empty array.
// Setup the expression and expression-description
let amountExpression = NSExpression(forKeyPath: CoreDateWrapper.Attribute.amount)
let sumExpression = NSExpression(forFunction: "sum:", arguments: [amountExpression])
let sumDescription = NSExpressionDescription()
sumDescription.expression = sumExpression
sumDescription.expressionResultType = .decimalAttributeType
sumDescription.name = "sum"
// Setup the fetchRequest to only get the sum.
// I expect a dictionary as a result instead of a `NSManagedObject`
let sumFetch = NSFetchRequest<NSDictionary>(entityName: CoreDateWrapper.Entity.Transaction)
sumFetch.propertiesToFetch = [sumDescription]
sumFetch.resultType = .dictionaryResultType
// Fetch the sum
var sumResult: [String: Decimal]? = nil
do {
let array = try wrapper.context.fetch(sumFetch)
if let res = array.first as? [String: Decimal] {
sumResult = res
} else {
print("Wrong type for result")
}
} catch {
print("Error fetching result: \(error.localizedDescription)")
}
// Output the sum
if let sum = sumResult?["sum"] {
print("Total: \(sum)")
}
This always prints Wrong type for result because array is empty.
I am consuming an API that gives me the next page in the Header inside a field called Link. (For example Github does the same, so it isn't weird.Github Doc)
The service that I am consuming retrieve me the pagination data in the following way:
As we can see in the "Link" gives me the next page,
With $0.response?.allHeaderFields["Link"]: I get </api/games?page=1&size=20>; rel="next",</api/games?page=25&size=20>; rel="last",</api/games?page=0&size=20>; rel="first".
I have found the following code to read the page, but it is very dirty... And I would like if anyone has dealt with the same problem or if there is a standard way of face with it. (I have also searched if alamofire supports any kind of feature for this but I haven't found it)
// MARK: - Pagination
private func getNextPageFromHeaders(response: NSHTTPURLResponse?) -> String? {
if let linkHeader = response?.allHeaderFields["Link"] as? String {
/* looks like:
<https://api.github.com/user/20267/gists?page=2>; rel="next", <https://api.github.com/user/20267/gists?page=6>; rel="last"
*/
// so split on "," the on ";"
let components = linkHeader.characters.split {$0 == ","}.map { String($0) }
// now we have 2 lines like '<https://api.github.com/user/20267/gists?page=2>; rel="next"'
// So let's get the URL out of there:
for item in components {
// see if it's "next"
let rangeOfNext = item.rangeOfString("rel=\"next\"", options: [])
if rangeOfNext != nil {
let rangeOfPaddedURL = item.rangeOfString("<(.*)>;", options: .RegularExpressionSearch)
if let range = rangeOfPaddedURL {
let nextURL = item.substringWithRange(range)
// strip off the < and >;
let startIndex = nextURL.startIndex.advancedBy(1) //advance as much as you like
let endIndex = nextURL.endIndex.advancedBy(-2)
let urlRange = startIndex..<endIndex
return nextURL.substringWithRange(urlRange)
}
}
}
}
return nil
}
I think that the forEach() could have a better solution, but here is what I got:
let linkHeader = "</api/games?page=1&size=20>; rel=\"next\",</api/games?page=25&size=20>; rel=\"last\",</api/games?page=0&size=20>; rel=\"first\""
let links = linkHeader.components(separatedBy: ",")
var dictionary: [String: String] = [:]
links.forEach({
let components = $0.components(separatedBy:"; ")
let cleanPath = components[0].trimmingCharacters(in: CharacterSet(charactersIn: "<>"))
dictionary[components[1]] = cleanPath
})
if let nextPagePath = dictionary["rel=\"next\""] {
print("nextPagePath: \(nextPagePath)")
}
//Bonus
if let lastPagePath = dictionary["rel=\"last\""] {
print("lastPagePath: \(lastPagePath)")
}
if let firstPagePath = dictionary["rel=\"first\""] {
print("firstPagePath: \(firstPagePath)")
}
Console output:
$> nextPagePath: /api/games?page=1&size=20
$> lastPagePath: /api/games?page=25&size=20
$> firstPagePath: /api/games?page=0&size=20
I used components(separatedBy:) instead of split() to avoid the String() conversion at the end.
I created a Dictionary for the values to hold and removed the < and > with a trim.
I have the following URL query:
encodedMessage=PD94bWwgdmVyNlPg%3D%3D&signature=kcig33sdAOAr%2FYYGf5r4HGN
How can I split the query to get the of encodedMessage and signature values?
The right way to achieve this is to work with URLComponents:
A structure designed to parse URLs based on RFC 3986 and to construct
URLs from their constituent parts.
By getting the url components host string and queryItems array, as follows:
if let urlComponents = URLComponents(string: "http://mydummysite.com?encodedMessage=PD94bWwgdmVyNlPg%3D%3D&signature=kcig33sdAOAr%2FYYGf5r4HGN"), let host = urlComponents.host, let queryItems = urlComponents.queryItems {
print(host) // mydummysite.com
print(queryItems) // [encodedMessage=PD94bWwgdmVyNlPg==, signature=kcig33sdAOAr/YYGf5r4HGN]
}
queryItems array contains URLQueryItem objects, which have name and value properties:
if let urlComponents = URLComponents(string: "http://mydummysite.com?encodedMessage=PD94bWwgdmVyNlPg%3D%3D&signature=kcig33sdAOAr%2FYYGf5r4HGN"),let queryItems = urlComponents.queryItems {
// for example, we will get the first item name and value:
let name = queryItems[0].name // encodedMessage
let value = queryItems[0].value // PD94bWwgdmVyNlPg==
}
Also:
In case of you are getting the query without the full url, I'd suggest to do a pretty simple trick, by adding a dummy host as a prefix to your query string, as follows:
let myQuery = "encodedMessage=PD94bWwgdmVyNlPg%3D%3D&signature=kcig33sdAOAr%2FYYGf5r4HGN"
let myDummyUrlString = "http://stackoverflow.com?" + myQuery
if let urlComponents = URLComponents(string: myDummyUrlString),let queryItems = urlComponents.queryItems {
// for example, we will get the first item name and value:
let name = queryItems[0].name // encodedMessage
let value = queryItems[0].value // PD94bWwgdmVyNlPg==
} else {
print("invalid url")
}
You can get the key value pairs this way:
let str = "encodedMessage=PD94bWwgdmVyNlPg%3D%3D&signature=kcig33sdAOAr%2FYYGf5r4HGN"
let arr = str.components(separatedBy:"&")
var data = [String:Any]()
for row in arr {
let pairs = row.components(separatedBy:"=")
data[pairs[0]] = pairs[1]
}
let message = data["encodedMessage"]
let sig = data["signature"]
I am not sure if that's what you were looking for or not. If it is not, could you please clarify a bit further as to what you are looking for?