Got error of advancedBy on Swift3 conversion - swift3

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)

Related

Swift 2 to 3 conversion error with Value of type '[Any]' has no member

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.

Swift thinks my string is an MDL material

I'm trying to save data in an image metadata in iOS/Swift3. It does not appear that CG will let you save out custom tags (is that true?) so I JSON encoded my dictionary and put the result as a string into the TIFF tag's ImageDescription. When I load the image and get the metadata back...
if let data = NSData(contentsOfFile:oneURL.path), let imgSrc = CGImageSourceCreateWithData(data, options as CFDictionary) {
let allmeta = CGImageSourceCopyPropertiesAtIndex(imgSrc, 0, options as CFDictionary) as? [String : AnyObject]
The allMeta contains (among other things):
▿ 0 : 2 elements
- key : ImageDescription
- value : {
"CameraOrientationW" : 0.1061191,
"CameraOrientationZ" : -0.01305595,
"CameraOrientationX" : 0.01319851,
"CameraOrientationY" : 0.9941801
}
Which has the JSON data, yay! So now I simply have to get the TIFF metadata, get the ImageDescription from that, and de-JSON it...
let tiffmeta = allmeta?["{TIFF}"]
if let tiffMeta = tiffmeta {
let descmeta = tiffMeta["ImageDescription"]
var descdata = descmeta?.data(usingEncoding: NSUTF8StringEncoding)!
let descdict = try? JSONSerialization.jsonObject(with: descdata, options: [])
But this will not compile. Xcode puts an error on the let descdata line:
Value of type 'MDLMaterialProperty??' has no member 'data'
I tried casting it to String on the line above, at which point it complains I didn't unwrap the optional MDLMaterialProperty.
Am I missing something obvious here?
So just to close this one, this appears to be a problem in the compiler. I made a number of minor changes to the syntax, nothing that had any actual effect on the code, and suddenly it decided the object was indeed a string.

cast from float to nsdecimalnumber always fails swift

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
}

What Causes DynamoDB UpdateItem to Giv Fatal Error in Swift?

I am using Swift to let my app update an item on DynamoDB. I followed the example https://github.com/aws/aws-sdk-ios/blob/master/AWSiOSSDKTests/AWSDynamoDBTests.m#L244, the "- (void)testUpdateItem" method. My codes are as follows:
var dynamoDB = AWSDynamoDB()
var hashValue: AWSDynamoDBAttributeValue = AWSDynamoDBAttributeValue()
hashValue.S = userID
var updatedValue: AWSDynamoDBAttributeValue = AWSDynamoDBAttributeValue()
updatedValue.S = updatedContent
var updateInput: AWSDynamoDBUpdateItemInput = AWSDynamoDBUpdateItemInput()
updateInput.tableName = kAWSDynamoDBMoEndpointARNTableName
updateInput.key = ["UserID": hashValue]
var valueUpdate: AWSDynamoDBAttributeValueUpdate = AWSDynamoDBAttributeValueUpdate()
valueUpdate.value = updatedValue
valueUpdate.action = AWSDynamoDBAttributeAction.Put
updateInput.attributeUpdates = ["Updated": valueUpdate]
updateInput.returnValues = AWSDynamoDBReturnValue.UpdatedNew
dynamoDB.updateItem(updateInput).waitUntilFinished()
However, as I run the codes, it always returns fatal error: unexpectedly found nil while unwrapping an Optional value. Looking into the error, I can find it is from Swift._fatalErrorMessage (Swift.StaticString, Swift.StaticString, Swift.StaticString, Swift.Uint) -> () with Thread 1: EXC_BREAKPOINT (code=EXC_ARM_BREAKPOINT, subcode=0xe7ffdefe)
I didn't use .continueWithBlock or .continueWithSuccessBlock cuz neither helps to catch the error.
Any idea why? THANKS
You need to get an instance of AWSDynamoDB as follows:
let dynamoDB = AWSDynamoDB.defaultDynamoDB()
You are using the default - init method without any parameter, and it causes AWSDynamoDB instance to have no AWSServiceConfiguration.
With the current AWS, found that this worked well for posting the updateItem in Swift.
dynamoDB.updateItem(updateInput) .continueWithExecutor(AWSExecutor.mainThreadExecutor(), withBlock: { (task:AWSTask!) -> AnyObject! in
if (task.error == nil) {
log.debug("task.error == nil")
}
return nil
})
// instead of
dynamoDB.updateItem(updateInput).waitUntilFinished()

iOS 8 prepare for segue Casting object. Gives Error

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: