UI-based Application Architecture

-

For reducing coupling between model, view and business logic to increase unit testing compatibility different architectures are used. I am studying in the perspective of ios platform.



MVC: Model-View-Controller

Model: 
Model classes are just data structure and manager of data structures like core data model classes and user-defined all model classes. The handler of core data models and json parser.

 View: 
Storyboards, xibs, UIView classes,
Controller:
UIViewController classes. which contain all business logic and presentation logic so this becomes a clumsy class and incompatible for unit testing.


MVP: Model-View-Presenter

 Presenter - For solving the problems with Controller of MVC presenter is used in MVP. The controller class is partitioned in different view classes with its own business logic so controller class is reduced in smaller size in presenter pattern.  But this also breaks SRP and unit testing problem does not solve yet using presenter class.

Model - Same as MVC
View - Same as MVC

MVVM: Model-View-ViewModel


This is a better approach than previous two.

M - Same as above
V - Same as above with UIViewController classes

ViewModel - This is completely different approach from MVC and MVP. In ViewModel, it contains only business logic without any presence of presentation logic or view components and any interaction with models. So this is unit testing supported and controller classes become slimmer than previous architectures.

Now UIViewCOntroller cannot ask to model for data rather it will request to ViewModel and it will communicate with model and send the requested data to UIViewController to present view. As it returns data needed for View not exactly given by Model, so it is called ViewModel.



Note: this need to be updated according to "clean architecture" of Uncle Bob

VIPER: View-Interactor-Presenter-Entity-Router

Interactor - Which contains the business logic only.Unlike ViewModel, it does not provide data to be presentable in view.

Presenter - This contains presentation logic means which view and how need to be shown. This communicates with Interactor to get data and create and send representable data to view which responsibility is added from ViewModel.

Entity - Same as Model

Router - View Routing will be maintained by this. Which view controller needs to be shown by this component with the required data.





Reference - https://medium.com/ios-os-x-development/ios-architecture-patterns-ecba4c38de52

Comments

Post a Comment

Popular posts from this blog

Thread & Locks

-
Image
Threads Threads are subunits of processes, which can be scheduled independently by the operating system scheduler. Multiple threads can be executed at the same time on a single CPU core. The operating system assigns small slices of computing time to each thread, so that it seems to the user as if multiple tasks are executed at the same time. If multiple CPU cores are available, then multiple threads can be executed truly in parallel. We can either use the POSIX thread API, or the Objective-C wrapper around this API, NSThread. NSThread is a simple Objective-C wrapper around pthreads. Grand Central Dispatch With GCD you don’t interact with threads directly anymore. Instead you add blocks of code to queues, and GCD manages a thread pool behind the scenes. GCD decides on which particular thread your code blocks are going to be executed on, and it manages these threads according to the available system resources. This alleviates the problem of too many threads being cre...
Read more

Opengl-es Buffer

-
Image
Framebuffer A  Framebuffer  is a collection of buffers that can be used as the destination for rendering. OpenGL has two kinds of framebuffers: the  Default Framebuffer , which is provided by the  OpenGL Context ; and user-created framebuffers called  Framebuffer Objects  (FBOs). The buffers for default framebuffers are part of the context and usually represent a window or display device. The buffers for FBOs reference images from either  Textures  or  Renderbuffers ; they are never directly visible. Default Framebuffer The Default Framebuffer is the Framebuffer that OpenGL is created with. It is created along with the OpenGL Context. Like Framebuffer Objects , the default framebuffer is a series of images. Unlike FBOs, one of these images usually represents what you actually see on some part of your screen. Framebuffer Object FBO contains a collection of rendering destinations; color, depth and stencil buffer. These logical buff...
Read more

Kernel Startup

-
Image
BootLoader GRUB Version 2 (GRUB) Stage 1 :  boot.img  is stored in the master boot record (MBR) or optionally in any of the  volume boot records  (VBRs), and addresses the next stage by an  LBA48  address (thus, the 1024-cylinder limitation of GRUB legacy is avoided); at installation time it is configured to load the first sector of  core.img . Stage 1.5 :   core.img  is by default written to the sectors between the MBR and the first partition, when these sectors are free and available. For legacy reasons, the first partition of a hard drive does not begin at sector 1 (counting begins with 0) but at sector 63, leaving 62 sectors of empty space not part of any partition or file system, and therefore not prone to any problems related with it. Once executed,  core.img  will load its configuration file and any other modules needed, particularly  file system  drivers; at installation time, it is generated from...
Read more