An Entity Manager is a core component of ORM (Object-Relational Mapping) frameworks, especially in Java (JPA – Java Persistence API), but also in other languages like PHP (Doctrine ORM).
Persisting:
Finding/Loading:
Retrieves an object by its ID or other criteria.
Example: $entityManager->find(User::class, 1);
Updating:
Tracks changes to objects and writes them to the database (usually via flush()
).
Removing:
Deletes an object from the database.
Example: $entityManager->remove($user);
Managing Transactions:
Begins, commits, or rolls back transactions.
Handling Queries:
Executes custom queries, often using DQL (Doctrine Query Language) or JPQL.
The Entity Manager tracks the state of entities:
managed (being tracked),
detached (no longer tracked),
removed (marked for deletion),
new (not yet persisted).
$user = new User();
$user->setName('Max Mustermann');
$entityManager->persist($user); // Mark for saving
$entityManager->flush(); // Write to DB
The Entity Manager is the central component for working with database objects — creating, reading, updating, deleting. It abstracts SQL and provides a clean, object-oriented way to interact with your data layer.
Aspect-Oriented Programming (AOP) is a programming paradigm focused on modularizing cross-cutting concerns—aspects of a program that affect multiple parts of the codebase and don't fit neatly into object-oriented or functional structures.
Typical cross-cutting concerns include logging, security checks, error handling, transaction management, or performance monitoring. These concerns often appear in many classes and methods. AOP allows you to write such logic once and have it automatically applied where needed.
Aspect: A module that encapsulates a cross-cutting concern.
Advice: The actual code to be executed (e.g., before, after, or around a method call).
Join Point: A point in the program flow where an aspect can be applied (e.g., method execution).
Pointcut: A rule that defines which join points are affected (e.g., "all methods in class X").
Weaving: The process of combining aspects with the main program code—at compile-time, load-time, or runtime.
@Aspect
public class LoggingAspect {
@Before("execution(* com.example.service.*.*(..))")
public void logBeforeMethod(JoinPoint joinPoint) {
System.out.println("Calling method: " + joinPoint.getSignature().getName());
}
}
This code automatically logs a message before any method in the com.example.service
package is executed.
Improved modularity
Reduced code duplication
Clear separation of business logic and system-level concerns
Can reduce readability (the flow isn't always obvious)
Debugging can become more complex
Often depends on specific frameworks (e.g., Spring, AspectJ)
Salesforce Apex is an object-oriented programming language specifically designed for the Salesforce platform. It is similar to Java and is primarily used to implement custom business logic, automation, and integrations within Salesforce.
Cloud-based: Runs exclusively on Salesforce servers.
Java-like Syntax: If you know Java, you can learn Apex quickly.
Tightly Integrated with Salesforce Database (SOQL & SOSL): Enables direct data queries and manipulations.
Event-driven: Often executed through Salesforce triggers (e.g., record changes).
Governor Limits: Salesforce imposes limits (e.g., maximum SOQL queries per transaction) to maintain platform performance.
Triggers: Automate actions when records change.
Batch Processing: Handle large data sets in background jobs.
Web Services & API Integrations: Communicate with external systems.
Custom Controllers for Visualforce & Lightning: Control user interfaces.
A Controller is a key component in the Model-View-Controller (MVC) architecture. It acts as an intermediary between the user interface (View) and the business logic or data (Model).
Handling User Input
Processing the Request
Interacting with the Model
Updating the View
Suppose a user wants to create a new blog post:
class BlogController extends Controller {
public function store(Request $request) {
// Validierung der Benutzereingabe
$request->validate([
'title' => 'required|max:255',
'content' => 'required',
]);
// Neues Blog-Post-Model erstellen und speichern
BlogPost::create([
'title' => $request->input('title'),
'content' => $request->input('content'),
]);
// Weiterleitung zur Blog-Übersicht
return redirect()->route('blog.index')->with('success', 'Post erstellt!');
}
}
✔ A controller manages the flow of an application and separates business logic from presentation.
✔ It ensures clean code structure, as each component (Model, View, Controller) has a specific responsibility.
✔ Modern frameworks like Laravel, Django, or ASP.NET often include built-in routing mechanisms that automatically direct requests to the appropriate controllers.
The Catalyst Framework is a flexible and powerful web framework for Perl. It enables the development of scalable and maintainable web applications and follows the Model-View-Controller (MVC) design pattern.
✅ MVC Architecture – Clear separation of business logic, presentation, and data management
✅ Flexibility – Supports various templating systems and ORM solutions like DBIx::Class
✅ Extensibility – Many plugins and modules available
✅ Asynchronous Capabilities – Can be integrated with event-driven architectures
✅ REST APIs & WebSockets – Support for modern web technologies
An object-oriented database management system (OODBMS) is a type of database system that combines the principles of object-oriented programming (OOP) with the functionality of a database. It allows data to be stored, retrieved, and managed as objects, similar to how they are defined in object-oriented programming languages like Java, Python, or C++.
Object Model:
Classes and Inheritance:
Encapsulation:
Persistence:
Object Identity (OID):
Complex Data Types:
Object-oriented databases are particularly useful for managing complex, hierarchical, or nested data structures commonly found in modern software applications.
The Document Object Model (DOM) is a standardized interface provided by web browsers to represent and programmatically manipulate structured documents, especially HTML and XML documents. It describes the hierarchical structure of a document as a tree, where each node represents an element, attribute, or text.
Tree Structure:
<html>
element, with child nodes such as <head>
, <body>
, <div>
, <p>
, etc.Object-Oriented Representation:
Interactivity:
<p>
element or insert a new <div>
.Platform and Language Agnostic:
1. Accessing an Element:
let element = document.getElementById("myElement");
2. Changing Content:
element.textContent = "New Text";
3. Adding a New Element:
let newNode = document.createElement("div");
document.body.appendChild(newNode);
The DOM is defined and maintained by the W3C (World Wide Web Consortium) standards and is constantly updated to support modern web technologies.
PSR-11 is a PHP Standard Recommendation (PHP Standard Recommendation) that defines a Container Interface for dependency injection. It establishes a standard way to interact with dependency injection containers in PHP projects.
PSR-11 was introduced to ensure interoperability between different frameworks, libraries, and tools that use dependency injection containers. By adhering to this standard, developers can switch or integrate various containers without modifying their code.
PSR-11 specifies two main interfaces:
ContainerInterface
This is the central interface providing methods to retrieve and check services in the container.
namespace Psr\Container;
interface ContainerInterface {
public function get(string $id);
public function has(string $id): bool;
}
get(string $id)
: Returns the instance (or service) registered in the container under the specified ID.has(string $id)
: Checks whether the container has a service registered with the given ID.2. NotFoundExceptionInterface
This is thrown when a requested service is not found in the container.
namespace Psr\Container;
interface NotFoundExceptionInterface extends ContainerExceptionInterface {
}
3. ContainerExceptionInterface
A base exception for any general errors related to the container.
PSR-11 is widely used in frameworks like Symfony, Laravel, and Zend Framework (now Laminas), which provide dependency injection containers. Libraries like PHP-DI or Pimple also support PSR-11.
Here’s a basic example of using PSR-11:
use Psr\Container\ContainerInterface;
class MyService {
public function __construct(private string $message) {}
public function greet(): string {
return $this->message;
}
}
$container = new SomePSR11CompliantContainer();
$container->set('greeting_service', function() {
return new MyService('Hello, PSR-11!');
});
if ($container->has('greeting_service')) {
$service = $container->get('greeting_service');
echo $service->greet(); // Output: Hello, PSR-11!
}
PSR-11 is an essential interface for modern PHP development, as it standardizes dependency management and resolution. It promotes flexibility and maintainability in application development.
PSR-7 is a PHP Standard Recommendation (PSR) that focuses on HTTP messages in PHP. It was developed by the PHP-FIG (Framework Interoperability Group) and defines interfaces for working with HTTP messages, as used by web servers and clients.
Request and Response:
PSR-7 standardizes how HTTP requests and responses are represented in PHP. It provides interfaces for:
Immutability:
All objects are immutable, meaning that any modification to an HTTP object creates a new object rather than altering the existing one. This improves predictability and makes debugging easier.
Streams:
PSR-7 uses stream objects to handle HTTP message bodies. The StreamInterface defines methods for interacting with streams (e.g., read()
, write()
, seek()
).
ServerRequest:
The ServerRequestInterface extends the RequestInterface to handle additional data such as cookies, server parameters, and uploaded files.
Middleware Compatibility:
PSR-7 serves as the foundation for middleware architectures in PHP. It simplifies the creation of middleware components that process HTTP requests and manipulate responses.
PSR-7 is widely used in modern PHP frameworks and libraries, including:
The goal of PSR-7 is to improve interoperability between different PHP libraries and frameworks by defining a common standard for HTTP messages.
PSR-2 is a coding style guideline for PHP developed by the PHP-FIG (Framework Interop Group) to make code more readable and consistent, allowing development teams to collaborate more easily. The abbreviation “PSR” stands for “PHP Standards Recommendation”.
{
for classes and methods should be on the next line, whereas braces for control structures (like if
, for
) should be on the same line.=
, +
).Here’s a simple example following these guidelines:
<?php
namespace Vendor\Package;
class ExampleClass
{
public function exampleMethod($arg1, $arg2 = null)
{
if ($arg1 === $arg2) {
throw new \Exception('Arguments cannot be equal');
}
return $arg1;
}
}
PSR-2 has since been expanded and replaced by PSR-12, which includes additional rules to further improve code consistency.