Magento 2 Technical

Direction

Chief Architect, Magento Commerce

Alan Kent

Goals of Continuous Platform Improvement

• Improve platform performance

• Reduce complexity

• Increase code consistency

• Reduce extension conflicts

Agenda

• Magento MVC & CQRS

• Persistence

• Customer Data & Sessions

• Inheritance Based APIs

• Classes vs Namespaces

• Deployment

MVC & CQRS

MVC

• Model - This is the part of your application

that defines its basic functionality behind a

set of abstractions. Data access routines

and some business logic can be defined in

the model.

• View - Views define exactly what is

presented to the user. Usually controllers

pass data to each view to render in some

format…

• Controller - Controllers bind the whole

pattern together. They manipulate models,

decide which view to display...

https://framework.zend.com

MVC comes from client applications

Fat client MVC

• Presentation is separate from Model

• State modification is separate from retrieval

Command & Query Responsibility

Segregation (CQRS)

Incorrect Server MVC

• Separation of Presentation from Model is preserved

• Violates HTTP (CQRS)

• State modification is done by same infrastructure as state retrieval (violates

CQRS)

Less Incorrect Server MVC

• Separation of Presentation from Model is preserved

• Obeys HTTP

• State modification is done by same infrastructure as state retrieval

Correct Server MVC

• Separation of Presentation from Model is preserved

• Obeys HTTP

• State modification and retrieval is partly done by different infrastructures

Correct MVC with CQRS

• Separation of Presentation from Model is preserved

• Obeys HTTP

• State modification and retrieval is done by different infrastructures

CQRS

• Separate Query API & Command API

• Command API – optimized for write, have business logic

• Query API – optimized for read, cacheable

• Query actualization through indexing

Data Persistence

evolution

Persistence

class AbstractModel

{

/**

* @deprecated

*/

public function save()

// …

/**

* @deprecated

*/

public function delete()

// …

}

Persistence of entities should be separate from

entities (element of DDD)

Persistence

$this->productResourceModel->save($product);

Services Interface

class ProductRepository implements ProductRepositoryInterface

{

public function createProduct(ProductInterface $product)

{

// All the logic goes here

}

}

Data Interface

interface ProductInterface

{

public function getSku();

public function setSku();

public function getName();

public function setName();

// only getters & setters

}

Service Contracts expose procedural API

Persistence

• OOP does not work well with Microservices

• No logic on models

• Persistence – just mapping data transfer objects to DB

Customer DATA &

Sessions

Request flow

Customer-agnostic content

(all routes)

Customer Data API (/sections/…)

Customer Data & Sessions

• No session usage in blocks

• Only Sections Controller knows about session

Discouraging

Inheritance

Class

Method

Code Reuse Options

Behavior

Parent Trait

DependencyFacade

Private

Problems With Inheritance

• Misused in 99% of cases

• Child depends on parent __construct()

• Static coupling – can’t substitute/decorate parent

• Performance problem: all parent dependencies are inherited

• Look at Product Model

Bad for performance! Kill!

Inheritance-based APIs

• Model -> DTOs

• Resource Model -> Data Mapping

• Collection -> Query API

• Block -> Interface subtyping

• Controller -> Interface subtyping

• …

Classes VS

Namespaces

Classes VS Namespaces

class IndexController

{

public function firstAction()

{

//…

}

public function secondAction()

{

//…

}

}

Classes VS Namespaces

class IndexController

{

public function __construct($dependencyA, $dependencyB)

//…

public function firstAction()

{

$this->dependencyA->doSmth();

}

public function secondAction()

{

$this->dependencyB->doSmth();

}

}

Classes VS Namespaces

class First implements Magento\Framework\App\ActionInterface

{

public function __construct($dependencyA)

//…

public function execute()

{

$this->dependencyA->doSmth();

}

}

Deployment

improvements

Deployment theory

Development Staging Production

How people do

Development Production

• Install DB

• Compile

• Deploy Static

How it’s supposed to work

Development Staging Production

• Compile

• Deploy Static

• Install DB • Install DB

Magento Deployment Improvements

• Compilation & static deployment DB-independent

• Allow to store System Configuration to files

• Move part of initial data to files (Stores, Theme config)

In summary we will:

• Continue applying CQRS on framework level

• Continue micro-service-ready approach

• Continue moving session management to browser

• Discourage inheritance and abandon inheritance-based APIs

• Stop using classes as namespaces

• Separate configuration from code

Q & A