Best iOS Architecture Patterns – MVC vs. MVP vs. MVVM vs. Viper

A formalized, modern architecture (highest level of system design) helps establish guidelines, patterns, and constraints according to which the code grows. It helps developers understand and predetermine how a system will work. The decision to adopt a particular architecture depends upon organizational and functional requirements.

iOS app architecture differs by Android as it is closed-source. These are similar in principle than in execution. iOS app architecture is programmed for security and has customized BSD kernel to program all their libraries from scratch. This does not use a lot of open-source software instead of customized software as opted by Apple. This means a lot of it may not even be required for your phone and is useless.  

What is an iOS architecture?

iOS architecture is layered. It contains an intermediate layer between the applications and the hardware so they are not able to communicate directly. Higher layers of architecture provide the user interface and sophisticated graphics while the lower layers in iOS provide the basic services. Many design patterns guide iOS architecture. These strengthen the foundation of the application. These help de-clutter the code, make it more organized and results in loosely coupled applications, easy to change/scalable modules, less likely of bug attack.

Layers in iOS architecture?

Apple provides System interfaces in special packages called frameworks. These are directories that hold a dynamic shared library like .a files, related resources like header files, images, and helper apps required to support that library. Every layer has a set of frameworks, which a developer uses to construct the applications.

iOS architecture consists of 4 primary layers: Cocoa Touch, Media, Core Services and Core OS Layer.

1. Cocoa Touch

Main functions:

• Cocoa became Cocoa Touch – the main API for apps to interface with the OS
• This layers provides the basic infrastructure for app management.
• Drives the UI – Provides the Controllers, Widgets, etc.
• Provides access to main system functions – Contacts, Camera, touch input, share with other apps, push notifications, etc.
• It is the first place one has to look for if they need any features within the app
• It is the key framework for building apps
• It provides basic infrastructure and support for key technologies.
• It includes various frameworks like: EventKit framework, GameKit Framework, iAd Framework, MapKit Framework, PushKitFramework, Twitter Framework, UIKit Framework

2. Media Layer

Main functions:

• It consists Graphics libraries – Core Graphics (Quartz), OpenGL, Metal, Photos Library, Animation
• Audio – Media player, OpenAL, Core Audio
• AirPlay-Support for graphics, audio and video
• This layer enables the use of graphics, audio and video technologies.
• Graphics Frameworks include: UIKit Graphics, Core Graphics framework, Core Animation, Core Images, OpenGl ES and GLKit, Metal
• Audio Frameworks include: Media Player Framework, AV Foundation, OpenAL,
  Video Framework, AV Kit – framework gives a collection of easy to use interfaces for presenting video, AV Foundation, Core Media

3. Core Services

Main Functions:

• This layer gives access to fundamental resources needed for app
• Built on Core Foundation and Foundation frameworks – These are the basis for NeXTSTEP
• It includes: Networking, iCloud, Encryption, SQLite, GPS, Telephony and SMS
• Facebook, Twitter
• Fundamental system services for the app
• Core foundation and foundation framework
• Support features such as location, icloud, social media and networking
• Important frameworks that are available in the core services layer include: Address book framework, Cloud Kit framework, Core data Framework, Core Foundation framework, Core Location framework, Core Motion Framework, Foundation Framework, Healthkit framework, Homekit framework, Social framework and StoreKit framework.

4. Core OS Layer

Main Functions:

• This layer utilizes things that are not frequent like use of Bluetooth for finding nearby devices in Linkedin (although this is a cross platform application).
• USB and other accessories
• Kernel operations
• Other low level features on which most other frameworks are built upon
• Use them for security and communication with hardware
• Important frameworks that are available in the Core OS Layer include: Core Bluetooth Framework, Accelerate Framework, External Accessory Framework, Security Services framework and Local Authentication framework.

How is iOS architecture different from android architecture?

iOS architecture has flat architecture as compared to Android OS app architecture. The lower levels inherits from higher levels but all the levels are accessible in similar ways. Some import more explicitly. Here are some alternative architectural approaches to build next quality apps:

Let’s find out what is Classic MVC architecture (design pattern) in iOS?

MVC consists of several more basic design patterns. Alternatively, it can be depicted as:

Or

(Source: dzone.com)

What problem it solves?

Primarily, MVC comes with reduced code complexity, code reuse, increased flexibility and decoupled code. MVC does not essentially resolve the code complexity problem. Neither has it solved the code re-use or no-flexibility problem. It also does not guarantee decoupled code.

MVC is required in the same proportion as there is a need to make use of jQuery for document.getElementById(), but this is merely a starting point in line with all the other Adapters, Factories, Singletons, Interpreters, Modules and Observers.

What is MVP architecture (design pattern) in iOS?

Or

(Source: dzone.com)

What problem it solves?

Starting a business can be full of risks. An MVP or minimum viable product helps to realign and to prioritize the important features. Developers aim to realize the product idea is apt and it is going to be a success.

Major reasons why most of the products fail are due to No market need, lack of cash, non-availability of right team, being outcompeted, pricing and cost issues, poor product, requirement or lack of business model, poor marketing, ignoring customers, product mistimed, lost focus, disharmony on team/investors, pivot gone bad, lack passion, bad location, no financing/investor interest, legal challenges, don’t use network/advisors, burn out and failure to pivot.

The primary purpose of an MVP is to launch a product or service quickly, based on the idea, with a small budget. This approach allows marketers to collect user’s feedback for the primary product and include it in future iterations. A business gets to find the right audience, fetch the right set of ideas based on experience and save an ample amount of time.

What is MVVM architecture (design pattern) in iOS?

(Image Source: dzone.com)

Or

(Source: medium.com)

What problem it solves?

MVVM can be used to transform models into another representation for a view. It is a great way to slim down massive view controllers that require several model-to-view transformations. It is widely accepted as a neat way to put all of the view configuration logic into the view model.

What is VIPER architecture (design pattern) in iOS?

Or

(Source: dzone.com)

What problem it solves?

Viper stands for View, Interactor, Presenter, Entity, and Routing. Clearly defined as a clean architecture for iOS apps, Viper divides an app’s logical structure into distinct layers of responsibility. This eases isolating dependencies (e.g. your database) and to test the interactions at the boundaries between various layers.

Various layers of Viper helps deal with the shortcomings of MVC and MVVM architecture. It also provides clear locations for application logic and navigation-related code. View controllers become leaner and code becomes easier to understand, test, reuse and maintain.

Also read: Is it MVP vs. MVC vs. MVVM that Creates an Odyssey for Android App Development?

Which approach forms an imperial decree for iOS development? MVC vs. MVP vs. Viper vs. MVVM?

While creating various mobile applications, a developer always tends to face different iOS architectural patterns depending upon the project requirements, type, and behavior. There is always a need to figure out the best architecture before initiating a project after consulting with business owners and clients. Patterns do not solve any problem, they help us. Quote your queries and get instant acknowledgment as you start with creating an iOS app. Contact us.