Iterating over a year to get each days NSDate object in Swift - ios

Question

Hello I have a method that returns an array of times for each day.
prayTimesDate(date: NSDate, latitide : Double, longitude : Double, timeZone : Double) -> NSMutableArray
I need to iterate through a whole year or maybe a date range to get an array of times for each day in a whole year. I found alot of references in ruby and python on how to do this but I couldn't find anything for swift or objective-c. Is there any built in methods in swift that will accomplish this? If not can someone help me out as I am still new in programming. Any input is greatly appreciated.
This is the objective-c code for the method I'm linking to my swift project
- (NSMutableArray *)prayerTimesDate:(NSDate *)date latitude:(double)latitude longitude:(double)longitude andTimezone:(double)timezone
{
unsigned unitFlags = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:unitFlags fromDate:date];
NSInteger year = [components year];
NSInteger month = [components month];
NSInteger day = [components day];
return [self getDatePrayerTimesForYear:year month:month day:day latitude:latitude longitude:longitude andtimeZone:timezone];
}

Answer 1

Assuming your prayerTimesDate: method is already returning the expected result, you can loop through each day of the year while repeatedly call prayerTimesDate: to get an array containing the prayer times for each day, ex:
func yearlyPrayerDatesFromCurrentDate (latitude:Double, longitude:Double, timezone:Double) -> NSMutableArray {
// Set "date" to equal the current day
var date:NSDate! = NSDate()
// Increment "date" by one year to calculate the ending
// date for the loop
let gregorian:NSCalendar! = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)
let dateComponents = NSDateComponents()
dateComponents.year = 1
let endingDate:NSDate! = gregorian.dateByAddingComponents(dateComponents, toDate: date, options: nil)
// Create an array to hold *all* the returned
// results for the year
var datesArray = NSMutableArray()
// Loop through each date until the ending date is
// reached
while date.compare(endingDate) != NSComparisonResult.OrderedDescending {
// Call your prayerTimesDate: method on the current
// date to get that date's prayer times and add the
// times from the returned array to the datesArray
datesArray.addObjectsFromArray(prayerTimesDate(date, latitude: latitude, longitude: longitude, andTimezone: timezone))
// increment the date by 1 day
let dateComponents = NSDateComponents()
dateComponents.day = 1
date = gregorian.dateByAddingComponents(dateComponents, toDate: date, options: nil)
}
return datesArray
}

Answer 2

Here is another example for a period over 14 days (without NSCalendar):
let ti:NSTimeInterval = 24*60*60 //one day
let dateFrom = NSDate() //Now
let dateTo = dateFrom.dateByAddingTimeInterval(24*60*60*14) //14 Days later
var nextDate = NSDate()
var endDate = dateTo.dateByAddingTimeInterval(ti)
while nextDate.compare(endDate) == NSComparisonResult.OrderedAscending
{
print("nextDate:", nextDate)
nextDate = nextDate.dateByAddingTimeInterval(ti)
}

Answer 3

Create an NSDateComponents instance for 1 day and NSDate objects for each time on the first day. Now you can iterate over the number of days you want (or until you hit then end date) and then you can use dateByAddingComponents:toDate:options: of the calendar to get the new date for each day.

Answer 4

From Apple doc: To compute a sequence of dates, use the enumerateDatesStartingAfterDate:matchingComponents:options:usingBlock: method instead of calling this method ( - nextDateAfterDate:matchingComponents:options: ) in a loop with the previous loop iteration's result.
As I got, it will iterate all dates that matched with "matchingComponents" till you finish iteration with "stop.memory = true"
//: Playground - noun: a place where people can play
import UIKit
let calendar = NSCalendar.currentCalendar()
let startDate = calendar.startOfDayForDate(NSDate())
let finishDate = calendar.dateByAddingUnit(.Day, value: 10, toDate: startDate, options: [])
let dayComponent = NSDateComponents()
dayComponent.hour = 1
calendar.enumerateDatesStartingAfterDate(startDate, matchingComponents: dayComponent, options: [.MatchStrictly]) { (date, exactMatch, stop) in
print(date)
if date!.compare(finishDate!) == NSComparisonResult.OrderedDescending {
// .memory gets at the value of an UnsafeMutablePointer
stop.memory = true
}
}