Question

For example:

There is a NSDateComponents *dueDate (Transformable) property of Task * entity. And there is intend of fetching all objects that have NSDate * value of dueDate less than [NSDate date]. NSDateComponents object is created of calendar units constant NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit.

[NSPredicate predicateWithFormat:@"dueDate < %@", [NSDate date]] is type mismatch. How to create NSDate object from dueDate before equation?

Or is there a better way to compare NSDateComponents?

Answer 1

I think I found the best solution.

Firstly i wrote a category:

@implementation NSDateComponents (SSDateComponent)

- (NSComparisonResult)compare:(NSDateComponents *)anotherDateComponents {
    return [[[NSCalendar currentCalendar] dateFromComponents:self] compare:[[NSCalendar currentCalendar] dateFromComponents:anotherDateComponents]];
}

Then i hope I can use <,>,== in predicate format. So I made NSDateComponents * from current date (which is also better for me) and my predicate looks like:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"dueDate < %@", dateComponents];

I was wondering if this could work because of Transformable type of dueDate in Core Data but it seems it works perfectly fine.