So my code below shows me how I am doing prepare for segue. I'm not sure whats going on but its giving me some weird error I've used this same way before and it works but it just won't work in this application.
Code
override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!)
{
if segue.identifier == "select"
{
println("helloworld")
var index = tableView.indexPathForCell(sender as UITableViewCell!)
var object = self.objects[index!.row] as HMAccessory // object is a NSmutableArray its crashing on this next line where im casting it
//var dest = segue!.destinationViewController? as CharacristicsViewController!
// dest.detailItem = object
}
}
can anybody see anything wrong with this?
This is the error I'm getting.
HomeKit`HomeKit.AccessoryTableViewController.prepareForSegue
(HomeKit.AccessoryTableViewController)(Swift.ImplicitlyUnwrappedOptional,
sender : Swift.ImplicitlyUnwrappedOptional) -> () at
AccessoryTableViewController.swift:23:
Related
I am experiencing a bit of trouble, while working on my app in SwiftUI.
I want to append relevant data, summarized in an object, to an array and return this.
While returning the array, I could see by debugging, that it is empty. Debugging in the for loop showed me, that location objects are created and appended, but are not being "saved" in the array. The "mapItems" array on the other hand has lots of members.
What am I missing?
Here is the method I came up with:
func searchForLocation(searchTerm: String) -> Array<Location>{
var locations = [Location]
let searchReqeust = MKLocalSearch.Request()
searchRequest.region = region //region is a published variable and is determined before
searchRequest.naturalLanguageQuery = searchTerm
let search = MKLocalSearch(request: searchRequest)
search.start{response, error in
//error handling
.
.
.
//empty response.mapItems handling
.
.
.
for item in response!mapItems{
let location = createLocationFromItem(item: item)
locations.append(location)
}
}
return locations
}
My locations class if following:
class Location: Identifiable{
var id= UUID()
var coordinates: CLLocationCoordinate2d
//And its proper init method
}
Your searchForLocation has an asynchronous function inside (search.start{...}),
and your code returns before it has finished getting the results.
To "wait" for the results use a completion/closure handler,
something like this:
func searchForLocation(searchTerm: String, completion: #escaping ([Location]) -> ()) {
var locations = [Location]() // <-- here
// ....
search.start{response, error in // <-- here asynchronous function
//... todo deal with errors, eg return completion([])
for item in response!mapItems {
let location = createLocationFromItem(item: item)
locations.append(location)
}
completion(locations) // <- here return when finished
}
}
and call the function like this:
searchForLocation(searchTerm: "Tokyo") { results in
print("\(results)") // <-- here results available, not before
}
I suggest you read-up on how to create and use asynchronous functions, these are important concepts to master to code effectively in Swift.
I'm having a problem with a Swift 2 to 3 conversion piece of work and some of the remains syntax giving: Value of type '[Any]' has no member errors.
I was hoping someone could point me at a good solution.
Swift 2 code
Swift 2 code
func search() {
epsonPrinters = [Printer]()
starPrinters = [Printer]()
epson_startSearching()
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)) { [unowned self] in
let devices = SMPort.searchPrinter()
self.starPrinters = devices.map { portInfo -> Printer in
let p = Printer(
id: portInfo.modelName,
make: "Star Micronics",
model: portInfo.modelName,
portName: portInfo.portName)
if let name = portInfo.modelName as? String {
p.emulation = name.containsString("TSP143") ? "StarGraphics" : "StarLine"
}
return p
}
}
}
Swift 3 Code (I've added comments above areas with errors)
func search() {
epsonPrinters = [Printer]()
starPrinters = [Printer]()
epson_startSearching()
DispatchQueue.global(qos: .background).async { [unowned self] in
let devices = SMPort.searchPrinter()
self.starPrinters = [devices.map { portInfo -> Printer in
// id, model and portName in below fails with messages like:
// Value of type '[Any]' has no member 'modelName'
let p = Printer(
id: portInfo.modelName,
make: "Star Micronics",
model: portInfo.modelName,
portName: portInfo.portName)
// error on portInfo.modelName
// Value of type '[Any]' has no member 'modelName'
if let name = portInfo.modelName as? String {
p.emulation = name.containsString("TSP143") ? "StarGraphics" : "StarLine"
}
return p
}!]
}
}
I know that I can replace the 'id:...' part with the likes of:
id: ((portInfo[0] as AnyObject).modelName) ?? "",
But this isn't correct because PortInfo can have none, 1 or multiples depending on the number of printers we find.
I'd appreciate any suggestions for refactoring this in an elegant way that is good Swift 3 syntax and likely to survive into Swift 4.
I'm working in Xcode 8.3.2
When you get some errors about types, you'd better check what type each variable has. When you select devices in the line let devices = ..., Quick Help of Xcode will show you something like this:
Declaration let devices: [Any]?
First, it's an Optional and you need to unwrap it, before using the actual content.
Second, the type of the elements in devices is Any, to which you cannot apply any methods (including property accessors). You need to cast it to an appropriate type at an appropriate place.
To solve the two things above, you can write something like this:
guard let devices = SMPort.searchPrinter() as? [PortInfo] else {
fatalError("This may never happen")
}
With guard statement above, Quick Help will show you:
Declaration let devices: [PortInfo]
Non-Optional, simple Array of PortInfo, so you can use any methods of PortInfo for the elements of this devices.
I would translate your Swift 2 code into Swift 3 like this:
func search() {
epsonPrinters = []
starPrinters = []
epson_startSearching()
DispatchQueue.global(qos: .default).async {
guard let devices = SMPort.searchPrinter() as? [PortInfo] else {
fatalError("This may never happen")
}
self.starPrinters = devices.map { portInfo -> Printer in
let p = Printer(
id: portInfo.modelName,
make: "Star Micronics",
model: portInfo.modelName,
portName: portInfo.portName)
if let name = portInfo.modelName {
p.emulation = name.contains("TSP143") ? "StarGraphics" : "StarLine"
}
return p
}
}
}
You may need some fixes (not many, I believe) to use this code, as you are not showing all relevant things such as the definition of Printer.
I'm converting my Swift2.3 code to Swift3, and got an error at the line where I used advancedBy. XCode showing me a replacing code that using offsetBy, but I still don't understand.
func unhideEmaimage(_ imageFile: String) {
let dotLocation = imageFile.characters.index(of: ".")
self.emaImage.texture = SKTexture(imageNamed: imageFile)
if dotLocation != nil {
let filenameInitial = imageFile.startIndex
let filenameLast = dotLocation!.advancedBy(-1)
let filenamePart:String = imageFile[filenameInitial...filenameLast]
}
And, following is the code that XCode showing me how to fix the error. However, I still don't know how to modify.
let filenameLast = "String.CharacterView corresponding to your index".index(dotLocation!, offsetBy: -1)
Please let me know the way to fix this error. Thank you in advance.
You should Write this:
let filenameLast = imageFile.index(dotLocation!,offsetBy: -1)
I am reading my data through a web service that returns a percentage as a string and I need to format it properly in my app. Currently I receive an error message that reads "Argument labels '(_:)' do not match any available overloads".
Suggestions on how to resolve this issue?
if let dUnInsured = result[0]["UnInsured"] as? String, let doubleNum = Double(dUnInsured) {
let sUnInsured = dollarFormatter.string(from: (NSDecimalNumber(Decimal(doubleNum))))!
self.inUninsured.text = sUnInsured
}
Try like this way.
if let dUnInsured = result[0]["UnInsured"] as? String, let doubleNum = Double(dUnInsured) {
let sUnInsured = dollarFormatter.string(from: (NSNumber(value: doubleNum)))!
self.inUninsured.text = sUnInsured
}
I am trying to use CMMotionManager to update the attitude of a camera viewpoint in scenekit. I am able to get the following code using the default reference to work.
manager.deviceMotionUpdateInterval = 0.01
manager.startDeviceMotionUpdates(to: motionQueue, withHandler:{ deviceManager, error in
if (deviceManager?.attitude) != nil {
let rotation = deviceManager?.attitude.quaternion
OperationQueue.main.addOperation {
self.cameraNode.rotation = SCNVector4(rotation!.x,rotation!.y,rotation!.z,rotation!.w)
}
}
})
I am however unable to get startDeviceMotionUpdates to work with a selected reference frame as shown below:
manager.deviceMotionUpdateInterval = 0.01
manager.startDeviceMotionUpdates(using: CMAttitudeReferenceFrameXMagneticNorthZVertical, to: motionQueue, withHandler:{ deviceManager, error in
if (deviceManager?.attitude) != nil {
let rotation = deviceManager?.attitude.quaternion
OperationQueue.main.addOperation {
self.cameraNode.rotation = SCNVector4(rotation!.x,rotation!.y,rotation!.z,rotation!.w)
}
}
})
The error i receive is:
Use of unresolved identifier 'CMAttitudeReferenceFrameXMagneticNorthZVertical'
I get similar error messages for other reference frames as well. Can anyone shed any light on the use of the "using:" parameter for the startDeviceMotionUpdates function? All the examples i have found are for older versions of swift or objective c so it is quite possible that it is simply an issue with not understanding Swift 3 syntax.
After some additional fiddling i figured out that the using argument expects a member of the new CMAttitudeReferenceFrame struct. i.e. it should be passed as:
manager.deviceMotionUpdateInterval = 0.01
manager.startDeviceMotionUpdates(using: CMAttitudeReferenceFrame.xMagneticNorthZVertical
,to: motionQueue, withHandler:{
deviceManager, error in
if (deviceManager?.attitude) != nil {
let rotation = deviceManager?.attitude.quaternion
OperationQueue.main.addOperation {
self.cameraNode.rotation = SCNVector4(rotation!.x,rotation!.y,rotation!.z,rotation!.w)
}
}
})
This is a change from earlier version that allowed the direct use of constants such as "CMAttitudeReferenceFrameXMagneticNorthZVertical"