Backend Development
PHP Tutorial
In-depth analysis of the observer pattern in PHP object-oriented programming
In-depth analysis of the observer pattern in PHP object-oriented programming
Aug 13, 2023 pm 06:34 PM
In-depth analysis of the observer pattern in PHP object-oriented programming
The observer pattern is a commonly used design pattern used to implement objects between objects in software systems of loose coupling. Its core idea is: an object (called an observer or subject) maintains a list of objects (called observers) that depend on it. When the state of the observed object changes, it will automatically notify all observers. . In this way, the observer pattern can realize a one-to-many relationship between objects. When an object changes, all related objects will be notified and can respond in time.
In the popular PHP object-oriented programming, the observer pattern is widely used to implement event-driven systems, messaging systems, and subscription and publishing systems. Below, we will deeply analyze the implementation of the observer pattern in PHP object-oriented programming and provide some code examples.
First, we define the subject interface, which contains the following methods:
interface Subject
{
public function attach(Observer $observer);
public function detach(Observer $observer);
public function notify();
}In this interface, we define three methods: attach is used to subscribe to observers, and detach is used to subscribe to observers. For unsubscribing observers, notify is used to notify all observers. Next, we implement a specific topic class:
class ConcreteSubject implements Subject
{
private $observers = [];
private $state;
public function attach(Observer $observer)
{
$this->observers[] = $observer;
}
public function detach(Observer $observer)
{
foreach ($this->observers as $key => $obs) {
if ($obs === $observer) {
unset($this->observers[$key]);
}
}
}
public function notify()
{
foreach ($this->observers as $observer) {
$observer->update();
}
}
public function getState()
{
return $this->state;
}
public function setState($state)
{
$this->state = $state;
$this->notify();
}
}In this specific topic class, we maintain an observer list and a state. Through the attach method, we can add observers to the list; through the detach method, we can remove observers from the list; through the notify method, we can notify all observers. When the state of the topic changes, we call the setState method to update the state and notify all observers subscribed to the topic.
Next, we define the Observer interface:
interface Observer
{
public function update();
}In this interface, we define a method update, which is used to do when the state of the observed changes. respond. Next, we implement a specific observer class:
class ConcreteObserver implements Observer
{
private $subject;
private $state;
public function __construct(Subject $subject)
{
$this->subject = $subject;
$this->subject->attach($this);
}
public function update()
{
$this->state = $this->subject->getState();
echo "Observer state updated: " . $this->state . "
";
}
public function getState()
{
return $this->state;
}
}In this specific observer class, we add the observer to the subject's observer list through the constructor method, and obtain the observer in the update method. Observer's state and perform some response operations.
Finally, we can write a test code to verify how the observer pattern works:
$subject = new ConcreteSubject(); $observer1 = new ConcreteObserver($subject); $observer2 = new ConcreteObserver($subject); $subject->setState(1); // 輸出：Observer state updated: 1 $subject->setState(2); // 輸出：Observer state updated: 2
In the above test code, we create a specific subject object and two specific observer objects , and adds the observer object to the subject object's observer list. Then, the observer's state update is triggered by setting the state of the subject object, and the updated state is output.
Through the above analysis and code examples, we have an in-depth understanding of the implementation of the observer pattern in PHP object-oriented programming. The observer pattern can help us achieve loose coupling between objects and make the system more flexible and scalable. In actual development, we can reasonably apply the observer pattern according to specific needs to improve the design quality and development efficiency of software systems.
The above is the detailed content of In-depth analysis of the observer pattern in PHP object-oriented programming. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
PHP calls AI intelligent voice assistant PHP voice interaction system construction
Jul 25, 2025 pm 08:45 PM
User voice input is captured and sent to the PHP backend through the MediaRecorder API of the front-end JavaScript; 2. PHP saves the audio as a temporary file and calls STTAPI (such as Google or Baidu voice recognition) to convert it into text; 3. PHP sends the text to an AI service (such as OpenAIGPT) to obtain intelligent reply; 4. PHP then calls TTSAPI (such as Baidu or Google voice synthesis) to convert the reply to a voice file; 5. PHP streams the voice file back to the front-end to play, completing interaction. The entire process is dominated by PHP to ensure seamless connection between all links.
How to use PHP to build social sharing functions PHP sharing interface integration practice
Jul 25, 2025 pm 08:51 PM
The core method of building social sharing functions in PHP is to dynamically generate sharing links that meet the requirements of each platform. 1. First get the current page or specified URL and article information; 2. Use urlencode to encode the parameters; 3. Splice and generate sharing links according to the protocols of each platform; 4. Display links on the front end for users to click and share; 5. Dynamically generate OG tags on the page to optimize sharing content display; 6. Be sure to escape user input to prevent XSS attacks. This method does not require complex authentication, has low maintenance costs, and is suitable for most content sharing needs.
How to use PHP combined with AI to achieve text error correction PHP syntax detection and optimization
Jul 25, 2025 pm 08:57 PM
To realize text error correction and syntax optimization with AI, you need to follow the following steps: 1. Select a suitable AI model or API, such as Baidu, Tencent API or open source NLP library; 2. Call the API through PHP's curl or Guzzle and process the return results; 3. Display error correction information in the application and allow users to choose whether to adopt it; 4. Use php-l and PHP_CodeSniffer for syntax detection and code optimization; 5. Continuously collect feedback and update the model or rules to improve the effect. When choosing AIAPI, focus on evaluating accuracy, response speed, price and support for PHP. Code optimization should follow PSR specifications, use cache reasonably, avoid circular queries, review code regularly, and use X
PHP creates a blog comment system to monetize PHP comment review and anti-brush strategy
Jul 25, 2025 pm 08:27 PM
1. Maximizing the commercial value of the comment system requires combining native advertising precise delivery, user paid value-added services (such as uploading pictures, top-up comments), influence incentive mechanism based on comment quality, and compliance anonymous data insight monetization; 2. The audit strategy should adopt a combination of pre-audit dynamic keyword filtering and user reporting mechanisms, supplemented by comment quality rating to achieve content hierarchical exposure; 3. Anti-brushing requires the construction of multi-layer defense: reCAPTCHAv3 sensorless verification, Honeypot honeypot field recognition robot, IP and timestamp frequency limit prevents watering, and content pattern recognition marks suspicious comments, and continuously iterate to deal with attacks.
How to use PHP to combine AI to generate image. PHP automatically generates art works
Jul 25, 2025 pm 07:21 PM
PHP does not directly perform AI image processing, but integrates through APIs, because it is good at web development rather than computing-intensive tasks. API integration can achieve professional division of labor, reduce costs, and improve efficiency; 2. Integrating key technologies include using Guzzle or cURL to send HTTP requests, JSON data encoding and decoding, API key security authentication, asynchronous queue processing time-consuming tasks, robust error handling and retry mechanism, image storage and display; 3. Common challenges include API cost out of control, uncontrollable generation results, poor user experience, security risks and difficult data management. The response strategies are setting user quotas and caches, providing propt guidance and multi-picture selection, asynchronous notifications and progress prompts, key environment variable storage and content audit, and cloud storage.
PHP realizes commodity inventory management and monetization PHP inventory synchronization and alarm mechanism
Jul 25, 2025 pm 08:30 PM
PHP ensures inventory deduction atomicity through database transactions and FORUPDATE row locks to prevent high concurrent overselling; 2. Multi-platform inventory consistency depends on centralized management and event-driven synchronization, combining API/Webhook notifications and message queues to ensure reliable data transmission; 3. The alarm mechanism should set low inventory, zero/negative inventory, unsalable sales, replenishment cycles and abnormal fluctuations strategies in different scenarios, and select DingTalk, SMS or Email Responsible Persons according to the urgency, and the alarm information must be complete and clear to achieve business adaptation and rapid response.
Beyond the LAMP Stack: PHP's Role in Modern Enterprise Architecture
Jul 27, 2025 am 04:31 AM
PHPisstillrelevantinmodernenterpriseenvironments.1.ModernPHP(7.xand8.x)offersperformancegains,stricttyping,JITcompilation,andmodernsyntax,makingitsuitableforlarge-scaleapplications.2.PHPintegrateseffectivelyinhybridarchitectures,servingasanAPIgateway
PHP integrated AI speech recognition and translator PHP meeting record automatic generation solution
Jul 25, 2025 pm 07:06 PM
Select the appropriate AI voice recognition service and integrate PHPSDK; 2. Use PHP to call ffmpeg to convert recordings into API-required formats (such as wav); 3. Upload files to cloud storage and call API asynchronous recognition; 4. Analyze JSON results and organize text using NLP technology; 5. Generate Word or Markdown documents to complete the automation of meeting records. The entire process needs to ensure data encryption, access control and compliance to ensure privacy and security.
