#ios-queryable is an Objective-C category that provides IQueryable and IEnumerable-like functionality to Core Data.
Tired of writing boilerplate Core Data code? Can't live without LINQ? ios-queryable is for you!
It supports query composition and deferred execution, and implements a subset of IEnumerable's methods, including where, take, skip, orderBy, first/firstOrDefault, single/singleOrDefault, count, any, and all.
It lets you write code like this:
NSArray* widgets = [[[[[self.managedObjectContext ofType:@"Widget"] where:@"Type == 'abc'"] orderBy:@"createddate"] take:5] toArray];instead of like this:
NSFetchRequest* fetchRequest = [[NSFetchRequest alloc] init]; NSEntityDescription* entity = [NSEntityDescription entityForName:@"Widget" inManagedObjectContext:self.managedObjectContext]; [fetchRequest setEntity:entity]; NSPredicate* predicate = [NSPredicate predicateWithFormat: @"type == 'abc'"]; [fetchRequest setPredicate:predicate]; NSSortDescriptor* sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"createddate" ascending:YES]; NSArray* sortDescriptors = [[NSArray alloc] initWithObjects: sortDescriptor, nil]; [fetchRequest setSortDescriptors:sortDescriptors]; [fetchRequest setFetchLimit:5]; NSError* error; NSArray* widgets = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];It also supports the NSFastEnumeration protocol, allowing for easy use in foreach loops:
foreach(Widget* widget in [self.managedObjectContext ofType:@"Widget"]) { // Do widgety stuff }#Usage To use ios-queryable, simply copy NSManagedObjectContext+IQueryable.h and NSManagedObjectContext+IQueryable.m into your project folder. Then, simply include the header file, and start writing your queries!
For examples, check out the tests in the tests project.