CODEWITHSUNDEEP
iphoneobjective-cioscore-data
tek3
tek3

Reputation: 2115

Can NSManagedObject class objects be used as models?

I have a bit confusion in choosing whether to use NSManagedObjet class objects directly as models or whether to create separate classess for models and create data mappers to map data from these model class to NSManagedObject class objects. Is there any harm in using Core Data objects as models ? What are the pros and cons of both approches?

Thanks in advance,

Regards,

tek3

Upvotes: 4

Views: 1251

Answers (2)

svena
svena

Reputation: 2779

I read your question and I take it you are not asking whether to use NSManagedObject directly or whether to subclass NSManagedObject, but if you should have your model as separate classes which use Core Data by explicit methods written by yourself.

Core Data is designed to act as the model layer for your application. I do not see any real benefits in having your own model classes, writing an interface for them and implementing it in core data behind the scenes, unless you really need the freedom to give up core data entirely at some point.

I recommend you create your model classes as subclasses of NSManagedObject. You are free to extend those in any way you deem necessary beyond what core data provides you, but at the same time your model classes will have full benefits from the core data framework: faulting, caching, data integrity assurances, cascade deletes, etc...

Upvotes: 3

Mundi
Mundi

Reputation: 80265

If you just use NSManagedObject, you will not have the benefit of the convenient "dot.notation" when referring to attributes and relationships.

Also, you will have to retrieve all values with valueForKey and set them with setValueForKey followed by strings. This can be extremely error prone and cumbersome and the resulting code is not nearly as readably as with the dot notation.

Finally, in your object classes you can implement all kinds of additional functionality. Where would you put this code otherwise? Remember the principle of encapsulation that helps produce independent and reusable code.

Upvotes: 1

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