Objective c - Suggested process to prefill complex DB - objective-c

Question

i would like to have some clarification about the correct approach to prefill a (complex) DB with multiple entities.
This is the approach i want to use:
Creation of a separate project that cares about DB Population
In case of Entities with no relations: parsing of a .json file in order to gather information of the Entity
In case of Entities with relation with other Entities (1:N relation):
I have a .json file for each entity
I allocate a Managed Object for each element involved with the relation between the Entities and i fill their attributes.
Please consider the example below for better explaination:
Let's consider the DB contains two Entities: Owner and House with a (1:N) relation.
In order to prefill the DB I:
configurea owner.json file and a house.json file
parse owner.json and gather and create a ManagedOwnerObject
parse house.json and create a set of ManagedHouseObject that have a relation with the first object created.
fill the attribute of ManagedOwnerObject that describe the relation with ManagedHouseObject with the NSSet just created
Iterate the process for all the house.json
Now, this process seems to me a little complex considering that my application has something like 10 Entities connected with 1:N relation.
Could you please suggest me if i'm doing right or if other better solutions could be considered?
Kind regards
Nicolò

Answer 1

You could simply fill the database manually using your app and ship the resulting SQLite file with your app instead of creating an empty one when the user opens the app for the first time.
EDIT:
Using KVC could simplify the creation of the objects. Setting the relationships probably isn't that easy. I would go through all of the data twice. Create the object without relationships in the first run and set up the relationships in the second.
Here is a method to do something similar, without relationships though:
-(void)createEntities:(NSString *)entityName fromFile:(NSString *)filePath inManagedObjectContext:(NSManagedObjectContext *)managedObjectContext {
// Remove all existing objects of this entity.
[self removeExistingEntriesForEntityName:entityName managedObjectContext:managedObjectContext];
// Read all data from file path.
NSArray *newObjects = [self readTestDataFromFilePath:filePath];
// Insert new object for all existing keys.
for (NSDictionary *no in newObjects) {
NSManagedObject *managedObject = [NSEntityDescription insertNewObjectForEntityForName:entityName inManagedObjectContext:managedObjectContext];
for (NSString *key in no.keyEnumerator) {
[managedObject setValue:[no valueForKey:key] forKeyPath:key];
}
}
[(AppDelegate *)[[UIApplication sharedApplication] delegate] saveContext];
}