I can able to read the descriptor value in the method "didUpdateValeFor descriptor:". Below is the log of the descriptor that I get from the BLE device.
<CBDescriptor: 0x1c445cb60, UUID = Characteristic Format, value = <08ff2427 013110>>
Values are in data format which is of some valid range from XX value to YY value and it is of type uint32 i guess. I couldn't able to convert them. I'm not able to get any solution from other answers.
In general, the CBDescriptor has a uuid property which will be one of the values specified in the documentation and a value property. The type of the value property will depend on the uuid. You can find the relevant value type in each of the possible CBDescriptor uuids. For example, for CBUUIDCharacteristicFormatString the value is a Data instance that encodes the format string.
A sample function that decodes a CBDescriptor is shown below. You would need to add the missing uuid types.
func descriptorDescription(for descriptor: CBDescriptor) -> String {
var description: String?
var value: String?
switch descriptor.uuid.uuidString {
case CBUUIDCharacteristicFormatString:
if let data = descriptor.value as? Data {
description = "Characteristic format: "
value = data.description
}
case CBUUIDCharacteristicUserDescriptionString:
if let val = descriptor.value as? String {
description = "User description: "
value = val
}
case CBUUIDCharacteristicExtendedPropertiesString:
if let val = descriptor.value as? NSNumber {
description = "Extended Properties: "
value = val.description
}
case CBUUIDClientCharacteristicConfigurationString:
if let val = descriptor.value as? NSNumber {
description = "Client characteristic configuration: "
value = val.description
}
case CBUUIDServerCharacteristicConfigurationString:
if let val = descriptor.value as? NSNumber {
description = "Server characteristic configuration: "
value = val.description
}
case CBUUIDCharacteristicAggregateFormatString:
if let val = descriptor.value as? String {
description = "Characteristic aggregate format: "
value = val
}
default:
break
}
if let desc=description, let val = value {
return "\(desc)\(val)"
} else {
return "Unknown descriptor"
}
}
For the specific decoding of the data associated with CBUUIDCharacteristicFormatString you need to refer to the Bluetooth documentation
Related
I got a dict of enum as key and values as object
#Published var subscriptionProducts = [SubscriptionType: SKProduct]()
enum SubscriptionType {
case monthly = "uniqueID"
case annualy = "uniqueID"
}
I got another array of type SKProduct
I want to assign it to my dict with a property of each object as key, and the object itself as value
Trying
subscriptionProducts = Dictionary(uniqueKeysWithValues:products.map({$0.productIdentifier , $0 }))
But I got
Type of expression is ambiguous without more context
the productIdentifier is of type String, how to assign it to the rawValue of my enum?
The result I want to achieve later is to get the specific object using that key
let monthlySubscriptionProduct = subscriptionProducts[.monthly]
You need to first declare your SubscriptionType enumeration RawValue as String. Then you will need to convert your productIdentifier String value to SubscriptionType using its fallible init(rawValue:) initializer. Something like:
enum SubscriptionType: String {
case monthly, annualy
}
let subscriptionProducts: [SubscriptionType: SKProduct] = Dictionary(uniqueKeysWithValues: products.compactMap {
guard let subscriptionType = SubscriptionType(rawValue: $0.productIdentifier) else {
return nil
}
return (subscriptionType, $0)
})
let monthlySubscriptionProduct = subscriptionProducts[.monthly]
But IMO that's not what you really want. Looks like what you are trying to accomplish is to group all monthly subscriptions which can be done using reduce as follow:
let subscriptionProducts: [SubscriptionType: [SKProduct]] = products.reduce(into: [:]) {
guard let subscriptionType = SubscriptionType(rawValue: $1.productIdentifier) else {
return
}
$0[subscriptionType, default: []].append($1)
}
let monthlySubscriptions = subscriptionProducts[.monthly] ?? []
I have parser in Objc, parser returns NSDictionary. I am using this parser in swift class. But when some value is missing on that dictionary, it shows nil value. e.g. ->
wirlessData = {
"anon" = {
};
"channel" = {
"text" = 1;
};
}
I am checking through
if let wepauthValue = wirlessData["wepauth"] {
if let value = wepauthValue["text"] {
print("\(value)") // nil
}
}
I don't how it satisfy the if let condition. Any one faced this types of problem can help me out.
Thanks,
vikash
You don't need any special code to do this, because it is what a dictionary already does. When you fetch dict[key] you know whether the dictionary contains the key, because the Optional that you get back is not nil (and it contains the value).
So, if you just want to answer the question whether the dictionary contains the key, ask:
let keyExists = dict[key] != nil
If you want the value and you know the dictionary contains the key, say:
let val = dict[key]!
But if, as usually happens, you don't know it contains the key - you want to fetch it and use it, but only if it exists - then use something like if let:
if let val = dict[key] {
// now val is not nil and the Optional has been unwrapped, so use it
}
I have tested it and found that value is still optional.Take a look at screenshot below to understand it better.
"anon" would be an empty dictionary. An empty dictionary is not nil, it is a dictionary. Just an empty one. A JSON parser will never, ever give nil values unless you ask for a key that is not in a dictionary. For example wirlessData ["nonexistingkey"] would give you nil.
If you be more type-strong about it with the if..let's then:
if let anonValue = wirlessData["anon"] {
if let value = anonValue["text"] as? String {
// This won't execute if value isn't converted from `anonvalue["text"]` to String specifically. This includes null been a false match too
print("\(value)") // nil
}else{
print("Value did't match string at all")
}
}
or even more specifically in your case:
if let anonValue = wirlessData["anon"] {
if let value = anonValue["text"] as? Int {
// This won't execute if value isn't converted from `anonvalue["text"]` to String specifically. This includes null been a false match too
print("\(value)") // nil
}else{
print("Value did't match int at all")
}
}
The value your parser is returning not nil, its empty so you need to check on count if inner data type is dictionary or array, I have past 1 sample here
Please use below code and correct your logic accordingly to get it work properly
let wirlessData:[String:AnyObject] = [
"anon" : [],
"channel" : [
"text" : 1
]
]
if wirlessData["anon"]?.count > 0 {
if let value = wirlessData["anon"]!["text"] {
print("\(value)") // nil
}
}
Try this below code using type check operator (is) -
if wirlessData["anon"] is [String:AnyObject]
{
let anon = wirlessData["anon"]!
print(anon)
if anon["random"] is String {
let stringValue = anon["random"]!
print("\(stringValue)")
}
else if anon["random"] is Int
{
let intValue = anon["random"]!
print("\(intValue)") // nil
}
else
{
print(" may be value did't match string & Int or nil ")
}
}
I have an Array: var messageArray = [AnyObject]() and in that Array there is a single tuple that contains Dictionaries with 10 key/value paires (9 of them not important for the sort): var messageDetailDict = [String: AnyObject]()
Getting and setting those values all work correctly, however now I want to sort the Array by 1 of the values (not keys) of the Dictionary.
Example -> The Array has a tuple containing several Dictionaries:
The key in the Dictionary (which is the first element in the Array) is: 'ReceivedAt' which has a value of 21-03-2015
The key in the Dictionary (which is the second element in the Array) is: 'ReceivedAt' which has a value of 20-03-2015
The key in the Dictionary (which is the third element in the Array) is: 'ReceivedAt' which has a value of 15-03-2015
Now the Array should be sorted so that the values of 'ReceivedAt' will be sorted from earliest date, to the last date.
Hope this makes sense, but it's a bit difficult to explain. Thanks!
EDIT >>>>>
This is the println(messageArray) output:
[(
{
ConversationId = "94cc96b5-d063-41a0-ae03-6d1a868836fb";
Data = "Hello World";
Id = "eeb5ac08-209f-4ef0-894a-72e77f01b80b";
NeedsPush = 0;
ReceivedAt = "/Date(1439920899537)/";
SendAt = "/Date(1436620515000)/";
Status = 0;
},
{
ConversationId = "94cc96b5-d063-41a0-ae03-6d1a868836fb";
Data = "Hello World";
Id = "86b8766d-e4b2-4ef6-9112-ba9193048d9d";
NeedsPush = 0;
ReceivedAt = "/Date(1439921562909)/";
SendAt = "/Date(1436620515000)/";
Status = 0;
}
)]
And the received date is converted to a string with the following method (I do think however this is not important, as it is a time interval, and therefore OK to sort):
func getTimeStampFromAPIValue(dateTimeReceived: String) -> String {
let newStartIndex = advance(dateTimeReceived.startIndex, 6)
let newEndIndex = advance(dateTimeReceived.endIndex, -2)
let substring = dateTimeReceived.substringWithRange(newStartIndex..<newEndIndex) // ell
let receivedAtValueInInteger = (substring as NSString).doubleValue
let receivedAtValueInDate = NSDate(timeIntervalSince1970:receivedAtValueInInteger/1000)
//format date
var dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "dd-MM-yy hh:mm"
var dateString = dateFormatter.stringFromDate(receivedAtValueInDate)
return dateString
}
Since the values of ReceivedAt are timestamps as strings you could apply the following algorithm:
var sortedArray = messageArray.sorted { (dict1, dict2) in
// Get the ReceivedAt value as strings
if let date1String = dict1["ReceivedAt"] as? String,
let date2String = dict2["ReceivedAt"] as? String {
// Compare the date strings to find the earlier of the two
return date1String.compare(date2String) == .OrderedAscending
}
// Couldn't parse the date, make an assumption about the order
return true
}
Try this, change OrderedAscending with OrderedDescending if need in inverse order
messageArray.sortInPlace {
($0["ReceivedAt"] as! NSDate).compare($1["ReceivedAt"] as! NSDate) == .OrderedAscending
}
I have two orgunit_id's, test["orgunit_id"] and API.loginManagerInfo.orgUnit, which I would like to compare. The problem is that the variables have different types. test["orgunit_id"] is value of a NSDictionary and the other one is a String.
I've tried several ways to cast it into Integers, but without success.
Code:
if(!orgUnits.isEmpty){
print(orgUnits) //See at console-output
for test: NSDictionary in orgUnits {
println(test["orgunit_id"]) //See at console-output
println(API.loginManagerInfo.orgUnit) //See at console-output
if(Int(test["orgunit_id"]? as NSNumber) == API.loginManagerInfo.orgUnit?.toInt()){ // This condition fails
...
}
}
}
Output:
[{
name = Alle;
"orgunit_id" = "-1";
shortdescription = Alle;
}, {
name = "IT-Test";
"orgunit_id" = 1;
shortdescription = "";
}]
Optional(-1)
Optional("-1")
Edit:
Here's the definition of API.loginManagerInfo.orgUnit: var orgUnit:String?
Use if let to safely unwrap your values and typecast the result.
If test["orgunit_id"] is an Optional Int and if API.loginManagerInfo.orgUnit is an Optional String:
if let testID = test["orgunit_id"] as? Int, let apiIDString = API.loginManagerInfo.orgUnit, let apiID = Int(apiIDString) {
if testID == apiID {
// ...
}
}
You may have to adapt this example given what is in your dictionary, but you get the point: safely unwrap the optional value and either typecast it (with if let ... = ... as? ...) or transform it (with Int(...)) before comparing.
I have this json result.
I would take the field "alert".
I try this:
var alert: NSString = jsonResult["features"]["properties"]["alert"]
but this is the error: does not have a member named 'subscript'.
I can not how to access a field in a nested dictionary
{
features = (
{
geometry = {
coordinates = (
"-97.95359999999999",
"37.2382",
5
);
type = Point;
};
id = usb000si7g;
properties = {
alert = green;
cdi = "5.8";
code = b000si7g;
detail = "http://earthquake.usgs.gov/earthquakes/feed/v1.0/detail/usb000si7g.geojson";
dmin = "0.017";
felt = 1258;
gap = 38;
ids = ",usb000si7g,";
mag = "4.3";
magType = mwr;
mmi = "4.94";
net = us;
nst = "<null>";
place = "8km SE of Harper, Kansas";
rms = "0.51";
sig = 864;
sources = ",us,";
status = reviewed;
time = 1412272884590;
title = "M 4.3 - 8km SE of Harper, Kansas";
tsunami = "<null>";
type = earthquake;
types = ",cap,dyfi,general-link,geoserve,losspager,moment-tensor,nearby-cities,origin,phase-data,shakemap,tectonic-summary,";
tz = "-300";
updated = 1412614943519;
url = "http://earthquake.usgs.gov/earthquakes/eventpage/usb000si7g";
};
type = Feature;
}
);
metadata = {
api = "1.0.13";
count = 1;
generated = 1412617232000;
status = 200;
title = "USGS Significant Earthquakes, Past Week";
url = "http://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/significant_week.geojson";
};
type = FeatureCollection;
}
I don't know what to do. swift is changed every beta.
As #Kirsteins said is his answer, you have to do a lot of unwrapping, and it's recommended to use a JSON library.
If you still want to stick with hand made extraction, then I suggest you to made it programmatically, such as adding an extension to NSDictionary as follows:
extension NSDictionary {
func objectForTreeKeys<T>(keys:[String]) -> T? {
var dict: NSDictionary? = self
var retValue: T?
for key in keys {
var value: AnyObject? = dict?.objectForKey(key)
if let unwrapped = value as? NSDictionary {
dict = unwrapped
} else if let unwrapped = value as? T {
retValue = unwrapped
break
} else {
retValue = nil
break
}
}
return retValue
}
}
You pass an array of keys to the function, and it traverses all nested dictionaries until:
a value of type T is encountered
a value having type different than NSDictionary and T is found
a nil value is found
In the first case, it returns the value of T type - in the other cases it returns nil.
You can use it as follows:
let ret: String? = jsonResult.objectForTreeKeys(["features", "properties", "alert"])
As you can see, it's a generic method, and the return type is inferred from the type of the variable the result is assigned to - so it's necessary to explicitly define its type, which must be optional (String? in this specific case).