If you are getting started as an iOS developer, the worst mistake that you can do is – not understanding what Core Data is and jumping into it. We recommend you understand the basics of Core Data and understand the ins and outs of the framework; this will help you stand out and will also ensure that the iOS app you develop has high performance and is one of the bests.
Wondering how you will figure out what Core Data is and how you should go about developing iOS applications? Well, to help you find the answers and get started as an iOS developer quickly, we have curated this article on Core Data. You can expect that you will have figured out the nitty-gritties of Core Data and will be capable of harnessing its full potential by the end of this article. So, let’s jump right into and learn more about Core Data and its effect on iOS applications.
What is Core Data in iOS Development?
If you are an iOS user, you might have noticed that a few applications operate offline (although they provide access to a few working features); for example, Apple’s iTunes (also Spotify) allows users to listen to their downloaded songs offline. Another great example is Amazon’s Audible that allows users to listen to their eBooks even without access to the internet. All of these offline features are possible because of a client-side caching framework called Core Data.
The Core Data framework has been designed and is maintained by Apple and has been a part of the industry for over 15 years. Its first occurrence can be tracked back to the macOS Tiger that was released in 2005. However, Apple made the framework available in iOS 3 that was launched in 2009.
Essentially, Core Data is Apple’s framework that provides developers with pre-defined modules which help them manage model layer objects present in their application. Let us have a brief look at what model layer objects are to help you better understand the concept – model layer objects can be thought of as application components that bind data into models (example – the user model has name, id, email, password, and username as properties). So, with Core Data’s provided modules, you can easily perform CRUD operations on the available objects. This is a huge advantage that greatly contributes to the popularity of iOS development.
Point to Note – Core Data in itself is not a database like SQL and MongoDB, but actually uses the in-built database system that is present in every iOS device – SQLite. SQLite is the actual relational database whereas Core Data is the framework managing object graphs.
What Does Managing Object Graphs Mean?
In simple terms, an object graph is nothing but a collection of objects that are connected with one another; you must be asking why is this relevant to Core Data? Well, the Core Data framework is great at managing object graphs and can easily take care of the lifecycle of all the objects present in the graph. Other than that, the framework also brings numerous capabilities like input validation, change tracking, and data model versioning to the table.
What are the Key Components of Core Data that Make it Popular?
In order for you to grasp Core Data’s full potential and empower your iOS development, you must understand what the key components of the framework are. Understanding these elements – Persistent Container, Managed Object Model, Managed Object Context and Store Coordinator – is crucial; after all, they form the foundation upon which sophisticated and high-performing iOS applications are built.
I. Persistent Container
In Core Data, the Persistent Container acts as the higher level abstraction class that helps in the encapsulation of the high priority components of the core data stack. Apple provides the NSPersistentContainer interface that makes the process of creating and handling the managed object model, persistent store container, and managed object context a lot easier.
II. Managed Object Context
When talking about data storage, we need to focus on a few operations that are also known as CRUD operations (create, read, update, save, and delete data). So, this is where the Managed Object Context comes into play and offers developers the ability to perform a few important functions. If you are looking to get access to seamless and feature-rich apps, we recommend you hire iOS developers with solid Core Data knowledge and relevant experience
III. Managed Object Model
The Managed Object model or MOM can be thought of as a blueprint of an application’s architecture that defines the structure, behavior, and relationships of the different data entities in the application. The different components of Core Data that contribute to a cohesive system that developers can utilize include:-
1. Entities
In terms of the object graph, entities are classes and have a name, properties, and sometimes relationships too. Every entity created and present can be considered to be an instance of the NSEntityDescription class. We can also think of entities as representations of real-world objects or concepts. Alternatively, you can also think of entities as the equivalent of database tables available in iOS development.
2. Attributes
These are the equivalent of columns of a database table and are used to define the properties or the characteristics of the available data. Attributes can be of different data types like integers, dates, strings, and more; generally, these are used in iOS development to associate each available entity to store specific information and shape their individual traits.
3. Relationships
One of the features of Core Data that make it stand out all the more is the framework’s ability to establish relationships between available entities. Since these relationships define associations between entities and describe how one affects the other, they will form the backbone of your application. Another great advantage of using Core Data is that it allows developers to seamlessly define different connections and relationships like one-to-one, one-to-many, and many-to-many.
4. Fetch Requests
Fetch Requests are also a crucial part of MOM and help retrieve data stored within entities. You can think of them as queries that help fetch data satisfying given conditions in iOS development.
So, the Managed Object Model can be thought of as a tool that helps developers structure an application’s data model. When you harness this power of Core Data, you will undoubtedly be able to build applications with seamless architecture and data retrieval and management capabilities.
IV. Persistent Store Coordinator
The last but the most important component is the persistent coordinator that acts as a bridge between the store or the database and the core data stack. Whenever an object context makes requests to fetch data, the persistent store coordinator loads the data from the SQLite store and passes all of it back to the object context.
Conclusion
Learning about the Core Data framework and its components can help you get ahead in iOS development and will undoubtedly be highly useful when creating functional and seamless applications. However, you must understand that it is a complex feature and should not be used if your application has a lightweight model layer. If you are not sure about whether your app must be based on Core Data or not, we recommend you get in touch with a professional iPhone app development company.
