Design patterns in Magento

Design patterns in Magento

MVC - Model View Controller

3

• Division into 3 main parts of the application:

• Model - represents the application logic

• View - describes how to display data within the user interface

• Controller - accepts input from the user, updates the model and refreshes the view

MVC

MVC

MVC in MVC

The view layer in Magento itself implements the MVC pattern.

M - blocksV - templates.phtmlC – layouts (.xml files)

MVC in MVCIn xml files we define the blocks, which are part of the view for a given controller action and assign the appropriate template to the main block

present the data obtained from the block

load and render the layoutdownload data from the model layer, process it and send to the template

Modularity

8

• Patterns orders grouping of individual functions in the project into modules

• Modules should not require other modules for proper operation

• Patterns define the directory structure within the parent module directory

Modularity

9

• Magento autoloader haspre-established search priorities

• Subdirectory structure is not only a matter of convention.

• Magento class name reflects its path

• The individual components of the Module must be explicitly declared the module configuration file

Modularity in Magento

code pools

Subdirectory structure in the module’s main directory

1

0

A short digression - Autoloader

Code pools are added in a pre-

defined order

set up php of our path of attaching files

registering the autoloader

1

1

A short digression - Autoloader

The autoloader is called upon class instantiation, unless there is already an object of a

given class in the memory - the file is already attached

note that this is not a built-in

implementation of __autoload () method

Attach the desired file

Factory method inMagento

1

3

Factory method in Magento

by the way - Singleton pattern in Magento

1

4

Factory method in Magento

1

5

What's under the hood?

we can also create a

class object by giving

its name

1

6

What's under the hood?

.....

divide the string of characters

first, look for overwritten classes

1

7

What's under the hood?

Magento adds a ‘mage' prefix as a

namespace

Registry

Registry

It allows you to place

objects and data in the global

pool, allowing access to them

from anywhere in the code

2

0

Registry

If you call a method with graceful parameter set to true,

you can avoid the occurence of an exception informing

you that there is a value under the given key

if at a given index there is an object that has a

destructor, use it

Event/Observer

2

2

Event/Observer

The extension code for theMagento core is locatedentirely in the Observerclass

2

3

How can you add your own observer?events node

name of the event

module name/class name

name of the calling method at

the event

unique observer ID

2

4

Event/Observer

calls the appropriate method

2

5

Event/Observer

Object $area represents certain parts of

the application (frontend, global, admin,

adminhtml)

download the configuration of events for

each part of the application

iterate through all observers for a given

part of the application

Assign a taable of observers to a table of

events under the key of an event name

that they are observing

2

6

Event/Observer

for each of the observers we try to call its

event operating procedures

assign the observer the

arguments transferred in the

event call

the function calling the observer’s method

call the method by transferring the observer’s

object with the arguments submitted earlier

Front controller

Front controller

It is the entrance gate for all requests directed at the running applications..It consists of two parts:• web handler - parses the

URL and determines whichcontroller is to be created

• command dispatch -creates a controller and forwards the request

2

9

Magento Front controller

our candidate

3

0

The front controller is designed to accept a request and decide what to do with it. Does it all really happen in the index.php file?

Is that so?

3

1

What's under the hood?

What have we here?

Get front controller

Call

Call

3

2

What's under the hood?

Iterate through router info table

containing the name of the router class

and its place of operation (frontend,

admin)

add the created router to the variable

_routers by the method addRouter (). We

will use them in the near future

also a default router is created and added

3

3

What's under the hood?

Use the completed _routers table

We adapt the request to the router. Match is a method of the abstract class Mage_Core_Controller_Varien_Router_Abstract, so each router defines its own body of this method

In the match() method, check if the request matches

the address of the router and, if so, transfer the request

to the target module controller

Send an answer to the http client

Prototype

Prototype

The Prototype pattern is a kind of extension of the abstract factory pattern. Since it hasn’t been discussed, it will be brieflydescribed below

A short digression – abstract facory

It defines a set of factory classes that inherit

from the abstract parent class (factory), which

specialize in creating groups of objects from

one family.

3

7

It all becomes clear

Prototype

It is a variation of abstract factory patternIt helps to limit the number of factories by creating a generic factory which is sent the types of objects to be produced

Prototype

3

9

Prototyp w Magento

4

0

the facory method is called and

we transfer a product object as a

parameter

Prototyp w Magento

4

1

download type id transferred in the

product parameter

from the type table and corresponding names of

model classes we download the one correct for

our product

concretize object type of a product and set up the

product to operate on

There are more design patterns in Magento, I strongly encourage you to explore them

Thank you for attention

[email protected]