Skip to main content

Deign Pattern in Drupal

 What are Design Patterns in General:

Description of communicating objects and classes that are customized to solve a general problem in a particular way.

Why design pattern required:

1 - Design pattern help to speed up the development,
2 - The templates are proven and from the developer's position, the Only implementation is required
3- Encapsulate big ideas in a simpler way
4 -  Each pattern describes a problem which occurs over & over again,

Design Pattern Inforces SOLID Principles:

SOLID is an acronym that stands for the following:

  • Single responsibility principle
  • Open/closed principle
  • Liskov substitution principle
  • Interface segregation principle
  • Dependency inversion principle
Categorization of GOF(Gang of Four Design Patterns)

- Creation - Used to construct objects such that they can be decoupled from their implementation system.

i.e in one class, we put business logic & in another class create the instance of it.

- Structural - Used to form large object structure between many disparate objects

-Behavioural - Used to manage algorithms, relationships, and responsibilities between objects


Design Patterns with Drupal 8 :

Drupal 8 is all about object-oriented PHP and contains concepts like,
  • Dependency Injection
  • Service Container
  • Factory Methods
  • PHP Traits
  • Discovery Methods
  • Strategy Pattern
  • Singleton Pattern
     Design Pattern is 4 Types:

    1 - Singleton Design Pattern
    2 - Factory Design Pattern
    3 - Mediator Design Pattern
    4 - Dependency Injection 

    1-Singleton Design Pattern(The Creational Pattern):

    Singleton Pattern which does not allow to create more than one instance of it.

    • It boosts performance by not allowing the creation of multiple objects to avoid the consumption of more memory by creating multiple objects.

    • Since the class controls the instantiation process, the class has the flexibility to change the instantiation process

    • Ease of Implementation

    2- Factory Design Pattern(The Creational Pattern)

    The Factory Method defines a method, which should be used for creating objects instead of a direct constructor call. The subclass can override this method to change the class of objects that will be created.
    Example: The factory method allow us to create an instance of the class by through the method, Instead of direct object creation. 


    3-Mediator Design Pattern (The behavioral Pattern)

    The mediator is a behavioral design pattern that reduces coupling between components of a program by making them communicate indirectly, through a special mediator object.

    Example: When we post a letter to someone, Then the postman is the mediator only who receives the latter & deliver the destination.

    Drupal 8 Example: Event & subscriber 


    4-Services & Dependency Injection in Drupal 8 :

    Drupal 8 Introduces the concept of services to decouple reusable functionality and makes these services pluggable & replaced by registered them with a service container.

    Services are used to perform operations like accessing the database, sending mail, etc









    Comments

    Post a Comment

    Popular posts from this blog

    Get The field values of node in Drupal 8

    use Drupal \ node \ NodeInterface ; /** * Implements hook_ENTITY_TYPE_insert() for node entities. * * This tests saving a node on node insert. * * @see \Drupal\node\Tests\NodeSaveTest::testNodeSaveOnInsert() */ function node_test_node_insert ( NodeInterface $node ) { // Set the node title to the node ID and save. if ( $node - > getTitle ( ) == 'new' ) { $node - > setTitle ( 'Node ' . $node - > id ( ) ) ; $node - > setNewRevision ( FALSE ) ; $node - > save ( ) ; } } Now There is so many functions are there to get the values, For All the functions available visit the API code, https://api.drupal.org/api/drupal/core%21modules%21node%21src%21NodeInterface.php/interface/NodeInterface/8.2.x Some of as below, Node edit form, Drupal 8 Automatically Load the whole object no need to load the entity like below, if ($event->getFormId() == 'node_alexa_audio_clips_edit_form') { $node = \Drupal::ro...
    Post a Comment
    Read more

    How to span column of custom table in Drupal

    If you want to span the column of custom drupal table like below image, Follow the below code to make the header of the table , <?php $header = array('S.N','District', array('data' => '<div class ="house">Household </div><br><span>Rural</span> <p>Urban</p>','colspan' => 2), array('data' => '<div class ="house">Members</div> <br><span>Rural</span> <p>Urban</p>','colspan' => 2), 'Duplicate/Failed Registration', array('data' => '<div class ="house">Pending De duplication </div><br><span>Rural</span> <p>Urban</p>','colspan' => 2), 'Non Un-organised Workers', 'SSID Generated', 'No. of Card Personlised', ); $rows[] = arra...
    1 comment
    Read more

    Dependency Injection in Drupal 8

    Here are the important nuggets: DI is a design pattern used in programming. DI uses composition. DI achieves inversion of control. Dependency == service that your class needs == object of a certain type. Inject == provide == compose == assemble. Container == service container == dependency container. Instead of using  \Drupal::service('foo_service') , get the service from the  $container  if using a class. And the important reasons: Externalizing dependencies makes code easier to test. It allows dependencies to be replaced without interfering with other functionality. Retrieving dependencies from the container is better for performance. Services: node.grant_storage The easiest examples to find are services that have arguments, because you can search *.services.yml files for the word "arguments". In  node.services.yml  for example, there is this entry: node.grant_storage: class: Drupal\node\NodeGrantDatabaseStorage argument...
    Post a Comment
    Read more