How to set NSDate > NSDate in Swift iOS 8?

Question

im attempting to only load posts that were created within 24 hours of the current time. Im having issues with the part where I set NSDate < NSDate, but being that NSDate is not an Int I don't know another way to accomplish the same task. Any help appreciated!

override func viewDidAppear(animated: Bool) {
    var annotationQuery = PFQuery(className: "Post")
    currentLoc = PFGeoPoint(location: MapViewLocationManager.location)
    //annotationQuery.whereKey("Location", nearGeoPoint: currentLoc, withinMiles: 10)
    annotationQuery.whereKeyExists("Location")
    annotationQuery.findObjectsInBackgroundWithBlock {
        (points, error) -> Void in
        if error == nil {
            // The find succeeded.
            println("Successful query for annotations")
            // Do something with the found objects

            let myPosts = points as! [PFObject]

            for post in myPosts {
                let point = post["Location"] as! PFGeoPoint
                let annotation = MKPointAnnotation()
                annotation.coordinate = CLLocationCoordinate2DMake(point.latitude, point.longitude)
                annotation.title = post["title"] as! String!
                let annotationSubTitleUser = post["username"] as! String!

                let formatter = NSDateFormatter()
                formatter.dateStyle = NSDateFormatterStyle.ShortStyle
                formatter.timeStyle = .ShortStyle
                let dateString = formatter.stringFromDate(post.createdAt!)


                var current = NSDate()
                var expireDate = NSDate(timeIntervalSinceNow: 60 * 60 * 24)

                annotation.subtitle = "User: \(annotationSubTitleUser)  Time: \(dateString)"


                //Here is where I am having issues setting current < expireDate
                if (current < expireDate) {
                    self.mapView.addAnnotation(annotation)
                }
            }

        } else {
            // Log details of the failure
            println("Error: \(error)")
        }
    }

}

Answer 1

If we are trying to compare dates, NSDate has a compare method which accepts another NSDate argument and returns an NSComparisonResult.

if date1.compare(date2) == .OrderedDescending {
    // date1 comes after date2
}

if date1.compare(date2) == .OrderedAscending {
    // date1 comes before date2
}

if date1.compare(date2) == .OrderedSame {
    // date1 and date2 are the same
}

Answer 2

Use:

if (current.timeIntervalSince1970() < expireDate.timeIntervalSince1970()) {
    self.mapView.addAnnotation(annotation)
}

instead.

Answer 3

Use this code..

 let interval = dateOne!.timeIntervalSinceDate(dateTwo!)
        var numberOfDays = interval/(3600*24)

        if (numberOfDays == 0) {
            println("same day") //dateOne = dateTwo
        }else if (numberOfDays>0){
            println("two > one") //dateOne > dateTwo
        }else if (numberOfDays<0){
            println("two < one") //dateOne < dateTwo
        }

This might helps you :)

Answer 4

In case you want to determine the earlier or the later between two dates, then the NSDate class can help you a lot towards this effort as it provides two methods named earlierDate and laterDate respectively. The syntax when using any of those methods is simple:

date1.earlierDate(date2)

And here’s how it works:

If the date1 object is earlier than date2, then the above method will return the value of the date1. If the date2 object is earlier than date1, then the value of the date2 will be returned. If the dates are equal, then the date1 is returned again. All the above apply for the laterDate as well.

The second method of comparing two NSDate objects involves the use of the compare method of the NSDate class and the NSComparisonResult enum

// Comparing dates - Method #2
if date1.compare(date2) == NSComparisonResult.OrderedDescending {
    print("Date1 is Later than Date2")
}
else if date1.compare(date2) == NSComparisonResult.OrderedAscending {
    print("Date1 is Earlier than Date2")
}
else if date1.compare(date2) == NSComparisonResult.OrderedSame {
    print("Same dates")
}

You can find out more from this Link.

Happy to help. :)