ActiveRecord

A lightweight Active Record implementation for Core Data.

License

Source code of this project is available under the standard MIT license. Please see the license file.

Usage

Simply import #import "ActiveRecord.h" (please see example)

// create an entity
Student *student = [Student create];
student.firstName = @"Adam";
student.lastName = @"Smith";
student.age = @21;

// commit changes in context
[Student commit];

// rollback context to last commit
[student delete];
[Student rollback];

// fetch all Student Objects
[Student objects];

// queries
[Student objects:@"age > 20"];
[Student objects:@"lastName == 'Smith'"];
[Student objects:@{@"age": @21, @"lastName": @"Smith"}];

// ordered queries
[Student ordered:@"lastName, age"]; // orders by name ASC, age ASC
[Student ordered:@"lastName, !age"]; // orders by name ASC, age DESC

[Student objects:@"age > 20" ordered:@"!age"];

// Erase all Student objects
[Student deleteAll];

JSON Serialization

Active Record allows you to create NSManagedObject instances directly from a JSON object (i.e. JSON string in the form of NSDictionary). As long as names of attributes and relationships in a JSON object matches the ones in your model, Active Record will do most of the heavy lifting for you.

For example, passing a file with JSON content below

{
    "uid": 0,
    "age": 32,
    "firstName": "Jaclyn",
    "lastName": "Petty",
    "course": {
        "uid": 1,
        "name": "Software Engineering"
    },
    "modules": [
        {
            "uid": 0,
            "name": "Module 0"
        },
        {
            "uid": 1,
            "name": "Module 1"
        }
    ],
    "registration": {
        "uid": 0,
        "signature": "8a700e2b-f14c-4b69-bcd6-f8baddabb1da"
    }
}

will result in creation of a Student object associated with one Course, one Registration object, and two Module objects.

id path = [[NSBundle mainBundle] URLForResource:@"Example" withExtension:@"json"];
id json = [NSData dataWithContentsOfURL:path];
id data = [NSJSONSerialization JSONObjectWithData:json options:kNilOptions error:nil];

id student = [Student createOrUpdateWithData:data];

For more detailed information, please see tests associated with this project.

Background Processing

Background processing with Active Record is straightforward. Simply execute your code on background thread and Active Record will do the rest. It will automatically create background context with NSConfinementConcurrencyType and will set it’s parent as your main (foreground) context.

This approach guarantees that each time you save (commit) changes in your child (background) context, they are pushed to your parent (main) context.

Please see example.

id students = [Factory fixture1000];

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    
    [students mk_each:^(id item) {
		[[Student createOrUpdateWithData:item] commit];
    }];
    
    dispatch_async(dispatch_get_main_queue(), ^{
		// notify about completion
    });
});

API

NSManagedObject+AR

+ (instancetype)createWithAutoID;
+ (instancetype)createWithID:(NSNumber *)objectID;
+ (instancetype)create;

+ (NSEntityDescription *)entityDescription;
+ (NSString *)entityName;
+ (NSString *)primaryKey;

+ (void)deleteAll;

- (void)assignAutoID;
- (void)delete;

NSManagedObject+AR_Finders

+ (BOOL)hasObjects;
+ (BOOL)hasObjects:(id)condition;
+ (BOOL)hasObjectsWithPredicate:(NSPredicate *)predicate;

+ (NSInteger)count;
+ (NSInteger)count:(id)condition;
+ (NSInteger)countWithPredicate:(NSPredicate *)predicate;

+ (instancetype)object:(id)condition;
+ (instancetype)objectWithID:(NSNumber *)objectID;
+ (instancetype)objectWithPredicate:(NSPredicate *)predicate;
+ (instancetype)objectWithMaxValueFor:(NSString *)attribute;
+ (instancetype)objectWithMinValueFor:(NSString *)attribute;

+ (NSArray *)orderedAscendingBy:(NSString *)key;
+ (NSArray *)orderedDescendingBy:(NSString *)key;
+ (NSArray *)ordered:(id)order;

+ (NSArray *)objects;
+ (NSArray *)objects:(id)condition;
+ (NSArray *)objects:(id)condition ordered:(id)order;
+ (NSArray *)objectsWithPredicate:(NSPredicate *)predicate;
+ (NSArray *)objectsWithPredicate:(NSPredicate *)predicate
               withSortDescriptor:(NSSortDescriptor *)descriptor;
+ (NSArray *)objectsWithPredicate:(NSPredicate *)predicate
              withSortDescriptors:(NSArray *)descriptors;

NSPredicate+AR

+ (instancetype)and:(NSArray *)conditions;
+ (instancetype)or:(NSArray *)conditions;

+ (instancetype)and:(id)cond1 :(id)cond2;
+ (instancetype)or:(id)cond1 :(id)cond2;

+ (instancetype)createFrom:(id)object;

- (instancetype)and:(id)condition;
- (instancetype)or:(id)condition;

NSSortDescriptor+AR

+ (NSArray *)descriptors:(id)object;
+ (instancetype)create:(id)object;
+ (instancetype)createWithKey:(NSString *)key ascending:(BOOL)ascending;

NSManagedObjectContext+AR

+ (instancetype)managedObjectContext;
+ (instancetype)mainContext;
+ (instancetype)backgroundContext;
+ (void)removeBackgroundContext;
+ (void)setBackgroundContext:(NSManagedObjectContext *)context;

NSManagedObjectContext+AR_Request

+ (NSFetchRequest *)requestWithPredicate:(NSPredicate *)predicate
                      withSortDescriptor:(NSSortDescriptor *)descriptor;

+ (NSFetchRequest *)requestWithPredicate:(NSPredicate *)predicate
                     withSortDescriptors:(NSArray *)descriptors;

NSFetchRequest+AR

+ (instancetype)createWithPredicate:(NSPredicate *)predicate
                 withSortDescriptor:(NSSortDescriptor *)descriptor;
+ (instancetype)createWithPredicate:(NSPredicate *)predicate
                withSortDescriptors:(NSArray *)descriptors;

Contributing

1. Fork it.
2. Create your feature branch (git checkout -b new-feature).
3. Commit your changes (git commit -am 'Added new-feature').
4. Push to the branch (git push origin new-feature).
5. Create new Pull Request.