#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.