Save NSDate and Doubles into Entity (CoreData) - ios

Question

I can get it to work fine using just Strings but if I try to use Doubles or NSDates then I get an error:
"Cannot assign value of type "NSDate?" to type "String?"
"Cannot assign value of type "Double?" to type "String?"
#IBAction func save(_ sender: Any) {
if item != nil {
item?.startdate = startDate.text
item?.pickup = pickup.text
item?.miles = miles.text
item?.company = company.text
item?.destination = destination.text
item?.enddate = endDate.text
} else {
let entitydescription = NSEntityDescription.entity(forEntityName: "Entity", in: pc)
let item = Entity(entity: entitydescription!, insertInto: pc)
item.startdate = startDate.text
item.pickup = pickup.text
item.miles = miles.text
item.company = company.text
item.destination = destination.text
item.enddate = endDate.text
}
do {
try pc.save()
} catch {
print(error)
return
}
navigationController!.popViewController(animated: true)
}
Here is what type each field is:
#NSManaged public var startdate: NSDate?
#NSManaged public var pickup: String?
#NSManaged public var miles: Double
#NSManaged public var company: String?
#NSManaged public var destination: String?
#NSManaged public var enddate: NSDate?

Answer 1

You need to convert miles.text, startdate.text and enddate.text to Double, NSDate and NSDate, respectively.
For startdate.text / enddate.text:
I'm not sure how what limit you have set for these values when the item is saved, but you should use a default value just incase the conversion fails. For this example, assume the dates are formatted "5/15/17" which takes the format M/d/y
let defaultDate = NSDate() //current date
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "M/d/y"
if let startDateText = startdate.text, let startDate = dateFormatter.string(from: startDateText) as? NSDate {
item?.startdate = startDate
} else {
item?.startdate = defaultDate
}
if let endDateText = startdate.text, let endDate = dateFormatter.string(from: endDateText) as? NSDate {
item?.startdate = endDate
} else {
item?.startdate = defaultDate
}
For miles.text:
Same idea, use a default value incase the conversion failed based on what the text will be for item.miles
if let milesText = miles.text {
item?.miles = Double(miles.text) ?? 0.0 //default is 0.0
} else {
item?.miles = 0.0
}
or an easy one-liner—
item?.miles = Double(miles.text ?? "0.0")
if there's a specific default value you have in mind, just declare it before you assign the item's property,
let defaultMilesStr = "0.432"
item?.miles = Double(miles.text ?? defaultMiles)
Also, just a tip, it's good practice to not leave optionals wrapped when assigning values. So even though there was check to make sure item != nil, it's overall better to safely unwrap item with a "guard" or "if-let". Since you are creating a new item if one doesn't exist, id go with if-let in this case:
if let item = item {
// assign values to item's prop's
// item.startdate = .....
} else if let entityDescription = NSEntityDescription.entity(forEntityName: "Entity", in: pc), let item = Entity(entity: entityDescription, insertInto: pc) {
// assign values to item's prop's
// item.startdate = .....
}
//further execution

Answer 2

Convert your date string to NSdate then you are able to save that
Try this code i have provide my date string you mat change with your format
let dateString = "Thu, 22 Oct 2015 07:45:17 +0000"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "EEE, dd MMM yyyy hh:mm:ss +zzzz"
dateFormatter.locale = Locale.init(identifier: "en_GB")
let dateObj = dateFormatter.date(from: dateString)
dateFormatter.dateFormat = "MM-dd-yyyy"

Answer 3

Try this :
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = /* date_format_you_want_in_string from
* http://userguide.icu-project.org/formatparse/datetime
*/
let date = dateFormatter.date(from: /* your_date_string */)
and set it as :
item?.date = date
For miles you can use :
if let dMiles = Double(miles.text!) {
item?.miles.text = dMiles
} else {
print("Not a valid Double: \(textField.text!)")
}
Hope it Helps!!