I am getting a headache due to UnsafePointer in Swift.
This is the method I want to call:
func CFDictionaryGetValue(theDict: CFDictionary!, _ key: UnsafePointer<Void>) -> UnsafePointer<Void>
And this is how I do it.
let ds: SCDynamicStoreRef = SCDynamicStoreCreate(nil, "setNet" as CFString, nil, nil)!
let list = SCDynamicStoreCopyProxies(ds)
print(list!)
print(CFDictionaryGetValue(list, UnsafePointer("HTTPPort")))
This however returns an error. I have no idea how to pass dictionary key to this method. If I remove the UnsafePointer("HTTPPort") and use "HTTPPort" instead I get a runtime error."
How can you access the dictionary values?
The easiest solution is to take advantage of the toll-free bridging
between CFDictionary and NSDictionary, and use the NSDictionary
accessor methods:
let ds = SCDynamicStoreCreate(nil, "setNet", nil, nil)!
if let list = SCDynamicStoreCopyProxies(ds) as NSDictionary? {
if let port = list[kSCPropNetProxiesHTTPPort as NSString] as? Int {
print("HTTPPort:", port)
}
}
But just for the sake of completeness: It can be done with
CFDictionaryGetValue:
if let list = SCDynamicStoreCopyProxies(ds) {
let key = kSCPropNetProxiesHTTPPort
let port = unsafeBitCast(CFDictionaryGetValue(list, unsafeAddressOf(key)), NSObject!.self)
if port != nil {
print("HTTPPort:", port)
}
}
Related
I've been struggling on an issue for some time now. I'm wondering why this code :
private func generateIdentity (base64p12 : String, password : String?, url : NSURL) {
let p12KeyFileContent = NSData(base64EncodedString: base64p12, options: NSDataBase64DecodingOptions(rawValue: 0))
if (p12KeyFileContent == nil) {
NSLog("Cannot read PKCS12 data")
return
}
let options = [String(kSecImportExportPassphrase):password ?? ""]
var citems: CFArray? = nil
let resultPKCS12Import = withUnsafeMutablePointer(&citems) { citemsPtr in
SecPKCS12Import(p12KeyFileContent!, options, citemsPtr)
}
if (resultPKCS12Import != errSecSuccess) {
print(resultPKCS12Import)
return
}
let items = citems! as NSArray
let myIdentityAndTrust = items.objectAtIndex(0) as! NSDictionary
let identityKey = String(kSecImportItemIdentity)
identity = myIdentityAndTrust[identityKey] as! SecIdentityRef
hasCertificate = true
print("cert cre", identity)
}
compiles, whereas this other one not :
private func generateIdentity (base64p12 : NSData, password : String?) {
let p12KeyFileContent = NSData(data: base64p12)
let options = [String(kSecImportExportPassphrase):password ?? ""]
var citems: CFArray? = nil
let resultPKCS12Import = withUnsafeMutablePointer(&citems) { citemsPtr in // line with the error
SecPKCS12Import(p12KeyFileContent!, options, citemsPtr)
}
if (resultPKCS12Import != errSecSuccess) {
print(resultPKCS12Import)
return
}
let items = citems! as NSArray
let myIdentityAndTrust = items.objectAtIndex(0) as! NSDictionary
let identityKey = String(kSecImportItemIdentity)
identity = myIdentityAndTrust[identityKey] as! SecIdentityRef
hasCertificate = true
print("cert cre", identity)
}
XCode tells me that :
Cannot convert value of type 'inout CFArray?' (aka 'inout Optional') to expected argument type 'inout _'
I really don't see how the 2 codes are different for the citems variable because what I basically just did was to use a NSData argument for the function, thus bypassing base64 string conversion to NSData.
The error message is super-confusing, but the cause of the error resides here:
SecPKCS12Import(p12KeyFileContent!, options, citemsPtr)
In your second example, with declaring let p12KeyFileContent = NSData(data: base64p12), the type of p12KeyFileContent is NSData, not NSData?. So, you cannot use ! for p12KeyFileContent.
Try changing the line as:
SecPKCS12Import(p12KeyFileContent, options, citemsPtr)
(! removed.)
One more.
You usually have no need to use withUnsafeMutablePointer to call SecPKCS12Import.
Try replacing these 3 lines (in your second example):
let resultPKCS12Import = withUnsafeMutablePointer(&citems) { citemsPtr in // line with the error
SecPKCS12Import(p12KeyFileContent!, options, citemsPtr)
}
with this:
let resultPKCS12Import = SecPKCS12Import(p12KeyFileContent, options, &citems)
The first example code can be rewritten as well.
Using Xcode 6.4 and programming in swift.
I am typing a program that should read in JSON from a URL. A sample of the JSON can be found at this URL (https://itunes.apple.com/us/rss/topmovies/limit=2/json) and Ive been using this site to parse the JSON in order to read it better (http://json.parser.online.fr/).
Now I need to work through the levels of the JSON in order to get to
the actual movie names and image URL's but I am lost at what kind of variable entryDictionary should be. I was thinking it should be an array of dictionaries, and this compiles, but the output of entryDictionary in the console is sloppy looking, starting with Optionl( and not entry{ as it should. And when I go to loop through entryDictionary, I get an error saying entry does not have a subscript of type AnyObject.
So I am asking how I retrieve the im:name fields and im:image from the JSON.
func downloadDataFromURLString(urlString: String) {
//Downloaded data and is now stored in data. Took code out because
//irrelevant to my problem at this point. Data variable has correct
//JSON, now I am trying to parse it.
} else { //download suceeded, time to parse
var error: NSError? = nil
var names = [String]()
if let rootDictionary = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: &error) as? [String: AnyObject] {
let feedDictionary = rootDictionary["feed"] as! [String: AnyObject]
let entryDictionary: AnyObject? = feedDictionary["entry"]
println(entryDictionary) //For debugging
//for entry in entryDictionary as! NSArray {
// let name = entryDictionary["name"]
// let image = entryDictionary["image"]
// let movie = Movie(name: name!, image: image!)
// weakSelf!.movies.append(movie)
//}
here is a blueprint of the JSON
"feed":{
"author":{},
"entry":[
{
"im:name":{
"label":"Deadpool"
},
"im:image":[],
"summary":{},
"im:price":{},
"im:contentType":{},
"rights":{},
"title":{},
"link":[],
"id":{},
"im:artist":{},
"category":{},
"im:releaseDate":{}
AnyObject is indeed not subscriptable (you're trying to subscript a variable whose type is AnyObject? with ["feed"]). You should also avoid casting to Cocoa container types like NSArray and NSDictionary whenever you can. Here's an example of how you might get the labels out of the entries array's names array:
import Foundation
func labels(feedDictionary:[String:AnyObject]) -> [String] {
guard let entries = feedDictionary["entry"] as? [String:AnyObject] else {
return []
}
return entries.flatMap { (key:String, value:AnyObject) -> String? in
guard key == "im:name" else {
return nil
}
guard let name = value as? [String:String] else {
return nil
}
return name["label"]
}
}
I'd however advise against using NSJSONSerialization on its own in Swift for anything but the simplest case, as you end up casting and wrapping optionals until the cows come home.
There are good 3rd party libraries such as Freddy and SwiftyJSON which apply Swift language features to accomplish a very convenient JSON (de)serialization experience.
For instance with Freddy you could express your problem in the following style:
let json = try JSON(data: data)
json.decode("feed", type:Feed.self)
struct Feed: JSONDecodable {
let entries:[Entry]
init(json: JSON) throws {
self.entries = try json.arrayOf("entry", type:Entry.self)
}
}
struct Entry:JSONDecodable {
let name:IMName
init(json: JSON) throws {
self.name = try json.decode("im:name", type:IMName.self)
}
}
struct IMName:JSONDecodable {
let label:String
init(json: JSON) throws {
self.label = try json.string("label")
}
}
I apologise for the title of this question. I have no idea what else to call it.
So... When calling the following:
let testData: [NSObject : AnyObject] = getTestData()
print(testData)
I get this output:
[data: {"TypeId":7,"DataList":null,"TypeName":"This is a test"}]
How would I be able to access the value 7 for the key "TypeId"?
EDIT:
Please note that it's holding { } brackets, not only [ ], thus a cast to NSDictionary is not possible as far as I have tried.
Kind regards,
Anders
You can achieve plist-like nested structures using Any type for dictionary values which is Swift's somewhat counterpart to Objective-C's id type but can also hold value types.
var response = Dictionary()
response["user"] = ["Login": "Power Ranger", "Password": "Mighty Morfin'"]
response["status"] = 200
Any seems to be better than AnyObject because in the above code response["status"] is of type Swift.Int, while using value type of AnyObject it is __NSCFNumber.
The way most people do it is to parse annoying JSON data as custom objects. That should be done as soon as you get the JSON. Ideally, data as JSON should not be used outside your communication code, example:
First, let's define a class to hold your server data:
class MyServerObject {
let typeId: Int
let typeName: String
let dataList: [AnyObject]?
init(dictionary: Dictionary<String, AnyObject>) {
let dataDictionary = dictionary["data"] as! Dictionary<String, AnyObject>
self.typeId = dataDictionary["TypeId"] as! Int
self.typeName = dataDictionary["TypeName"] as! String
self.dataList = dataDictionary["DataList"] as? [AnyObject]
}
}
Note that init method is already parsing the JSON. This doesn't have to be done in init, you could also create a static parse method that will return a new instance.
Usage:
// demo data
let jsonString = "{\"data\": {\"TypeId\":7,\"DataList\":null,\"TypeName\":\"This is a test\"}}"
let jsonData = jsonString.dataUsingEncoding(NSUTF8StringEncoding)!
let json = try! NSJSONSerialization.JSONObjectWithData(jsonData, options: [])
// parsing
let myServerObject = MyServerObject(dictionary: json as! Dictionary<String, AnyObject>)
// now we can simply read data as properties
print(myServerObject.typeId)
print(myServerObject.typeName)
One of the good thing about this solution is that we can check the JSON format and all the properties are parsed with the correct types.
Parsing can be hierarchical, for example, if your dataList contains complex objects, let's call them DataListItem, your parsing method can parse each item separately and put them into a [DataListItem], e.g.
if let dataListJSON = dataDictionary["DataList"] as? [Dictionary<String, AnyObject>] {
self.dataList = dataListJSON.map({ DataListItem($0) })
}
Also note that when parsing as! will crash the app when the format is invalid. as? will return nil if the types don't match. as? is very useful for types that can be nil because they are parsed as NSNull instances.
taking in account your data ...
print(testData)
/*
[data: {
DataList = null;
TypeId = 7;
TypeName = "This is a test";
}]
*/
// DataList type should be declared somewhere
class DataList {}
// parse data or set default value, if 'key' doesn't exist
if let data = testData["data"] as? [String:AnyObject] {
let dataList = data["DataList"] as? DataList // nil
let typeId = data["TypeId"] as? Int ?? 0 // 7
let typeName = data["TypeName"] as? String ?? "" // This is test
}
I am working on a turn based game with Game Center. I want to send an Array of Strings and an Array of Ints as matchData. I know how to create both, but I only know how to send one of them...
This is how i create the String Array:
var strings = [String]()
let data = NSKeyedArchiver.archivedDataWithRootObject(strings)
This is how i create the Int Array:
var array : [Int] = []
let data = NSData(bytes: array, length: array.count * sizeof(Int))
This is how I send the data i create
currentMatch?.endTurnWithNextParticipants([nextParticipant], turnTimeout: 20, matchData: data, completionHandler: { (error) in
if error != nil {
print(error)
} else {
//Data sent
}
}
})
The easiest way is probably to wrap both in a dictionary and then serialize the dictionary:
let data = NSKeyedArchiver.archivedDataWithRootObject([
"strings":strings,
"numbers":array
])
Then to recover the original data, you can use:
guard let recovered = NSKeyedUnarchiver.unarchiveObjectWithData(data) as? [String:AnyObject],
let strings = recovered["strings"] as? [String],
let array = recovered["numbers"] as? [Int] else {
// recovery failed... deal with it
}
Get your matchData using GKTurnBasedMatch.loadMatchDataWithCompletionHandler: and then use that match data if it exists in the completion block.
Why do I get an error when I used valueForKey... I am using same trick like in objectiveC ...
In ObjectiveC, the code is
self.strSubscribe =[responseObject[#"subscribe"] valueForKey:#"subscribe_ids"];
In Swift , the code is
self.strSubscribe = responseObject["subscribe"].valueForKey["subscribe_ids"] as! String
I declare the variables like
var arraySubCategory : NSMutableArray! = NSMutableArray()
var strSubscribe:String!
And I tried to access the value from below response
{
subscribe =
{
"subscribe_ids" = "1,14";
}
}
Edit
It works using Amit and Eric's solution but now for following data
{
data = (
{
"subscribe_ids" = "1,14";
}
);
}
let dictionary = responseObject["data"][0] as! Dictionary<String,AnyObject>
self.strSubscribe = dictionary["subscribe_ids"] as! String
OR//
if let dic = responseObject["data"][0] as? [String:String], let ids = dic["subscribe_ids"] {
self.strSubscribe = ids
}
but it gives me error:
could not find member 'subscript'
Swift doesn't know the type of responseObject["subscribe"], you have to help the compiler a bit; for example:
if let dic = responseObject["subscribe"] as? [String:String], let ids = dic["subscribe_ids"] {
self.strSubscribe = ids // "1,14"
}
UPDATE:
It's still the same problem: the compiler doesn't know the type of responseObject["data"], so when you try to access the subscript there's an error (because you know it's a dictionary inside the array, but the compiler doesn't).
One solution is to give the type to the compiler by declaring an array of dictionaries in the if let condition:
if let arr = responseObject["data"] as? [[String:String]], let ids = arr[0]["subscribe_ids"] {
self.strSubscribe = ids
}
Notice that it's [[String:String]] (array of dictionaries), not [String:String] (dictionary).
Write like this.
let dictionary = responseObject["subscribe"] as! Dictionary<String, AnyObject>
self.strSubscribe = dictionary["subscribe_ids"] as! String
Since responseObject["subscribe"] will give a AnyObject? output and AnyObject does not have any member called valueForKey.