search
HomeBackend DevelopmentPHP TutorialUsing factory pattern in PHP

A factory class refers to a class that contains a method specifically used to create other objects. The factory class is crucial in the practice of polymorphic programming. It allows dynamic replacement of classes and modification of configurations, which generally makes the application more flexible. , it is important for senior PHP developers to be proficient in factory mode.

The factory pattern is usually used to return different classes that conform to similar interfaces. A common use of factories is to create polymorphic providers, allowing us to decide which class should be instantiated based on application logic or configuration settings, such as , you can use such a provider to extend a class without having to refactor other parts of the application to use the new extended name.

Usually, the factory pattern has a key construct, which is a static method named Factory according to general principles. However, this is just a principle. The factory method can be named arbitrarily. This static method can also accept parameters of any data and must return an object.

Basic factory class

class MyObject{  
  //对象将从工厂返回  
}  
  
class MyFactory{  
public static function factory(){  
return new MyObject():  
   }  
}  
  
$instance=MyFactory::factory();

Use factory class to parse image files

Php code

<?php  
interface IImage{  
    function getHeight();  
    function getWidth();  
    function getData();  
}  
  
class Image_PNG implements IImage{  
      
    private $_width,$_height,$_data;  
      
    public function __construct($file){  
        $this->_file=$file;  
        $this->_parse();  
    }  
          
    private function _parse(){  
              
            //完成PNG格式的解析工作  
            //并填充$_width,$_height,$_data;  
        }  
          
          
    public function getWidth(){  
        return $this->_width;  
    }  
    public  function getHeight(){  
        return $this->_height;  
    }  
      
    public function getData(){  
       return $this->_data;  
      
    }  
      
}  
  
class Image_JPEG implements IImage{  
      
    private $_width,$_height,$_data;  
      
    public function __construct($file){  
        $this->_file=$file;  
        $this->_parse();  
    }  
          
    private function _parse(){  
              
            //完成JPEG格式的解析工作  
            //并填充$_width,$_height,$_data;  
        }  
          
          
    public function getWidth(){  
        return $this->_width;  
    }  
    public  function getHeight(){  
        return $this->_height;  
    }  
      
    public function getData(){  
       return $this->_data;  
      
    }  
      
}  
  
class ImageFactory{  
      
    public static function factory($file){  
        $pathParts=pathinfo($file);  
        switch (strtolower($pathParts[&#39;extension&#39;]))  
        {  
            case &#39;jpg&#39;:  
                $ret=new Image_JPEG($file);  
                break;  
            case &#39;png&#39;:  
                $ret=new Image_PNG($file);  
                break;  
                default:  
                    //有问题  
  
                      
        }  
        if($ret instanceof IImage){  
            return $ret;  
        }else {  
            //有问题  
        }  
    }  
}  
  
//当使用图像文件名调用 工厂方法时,根据传入的文件类型不同,取得不同对象。

Php code

//调用ImageFactoyr  
$image=ImageFactory::factory(&#39;/path/to/my.jpg&#39;);  
//$image是Image_JPEG类的一个实例  
echo $image->getWidth();

Use factory class to solve the problem of database portability. In database applications, the factory pattern can be used in the following two works in all aspects.

1. Make it easier for the software to support various database platforms to expand the user base

2. If the software is used internally and the database needs to be modified, the application can be easily migrated to another platform

In the code, a database table named User is created to test it. This table defines a varchar type field named email

Php code

<?php  
interface IDatabaseBindings{  
    public function userExists($email);  
}  
  
class PGSQL implements IDatabaseBindings{  
    protected $_connection;  
      
    public function __construct(){  
          
        $this->_connection=pg_connect(&#39;dbname=example_db&#39;);  
    }  
      
    public function userExists($email){  
          
        $emailEscaped=pg_escape_string($email);  
        $query="select 1 from users where email=&#39;".$emailEscaped."&#39;";  
        if($result=pg_query($query,$this->_connection)){  
            return (pg_num_rows($result)>0)?true:false;  
        }else{  
            return false;  
        }  
    }  
      
}  
  
class MYSQL implements IDatabaseBindings{  
      
    protected $_connection;  
      
    public function __construct(){  
          
        $this->_connection=mysql_connect(&#39;localhost&#39;);  
        mysql_select_db(&#39;example_db&#39;,$this->_connection);  
    }  
      
    public function userExists($email){  
          
        $emailEscaped=mysql_real_escape_string($email);  
        $query="select 1 from users where email=&#39;".$emailEscaped."&#39;";  
        if($result=mysql_query($query,$this->_connection)){  
            return (mysql_num_rows($result)>0)?true:false;  
        }else{  
            return false;  
        }  
    }  
      
}  
  
class DatabaseFactory{  
      
    public static function factory(){  
        $type=loadtypefromconfigfile();  
        switch ($type){  
            case &#39;PGSQL&#39;:  
                return new PGSQL();  
                break;  
            case &#39;MYSQL&#39;:  
                return new MYSQL();  
                break;  
        }  
    }  
}

The application does not have to know what type of database it is connected to , will only directly deal with the instances returned by the factory based on the rules defined by the IDatabaseBindings interface.

Php code

//调用DatabaseFactoy  
$db=DatabaseFactory::factory();  
$db->userExists(&#39;person@example.com&#39;);



For more articles related to the use of factory patterns in PHP, please pay attention to the PHP Chinese website!

Statement
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
The Continued Use of PHP: Reasons for Its EnduranceThe Continued Use of PHP: Reasons for Its EnduranceApr 19, 2025 am 12:23 AM

What’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.

PHP and Python: Exploring Their Similarities and DifferencesPHP and Python: Exploring Their Similarities and DifferencesApr 19, 2025 am 12:21 AM

PHP and Python are both high-level programming languages ​​that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.

PHP and Python: Different Paradigms ExplainedPHP and Python: Different Paradigms ExplainedApr 18, 2025 am 12:26 AM

PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.

PHP and Python: A Deep Dive into Their HistoryPHP and Python: A Deep Dive into Their HistoryApr 18, 2025 am 12:25 AM

PHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.

Choosing Between PHP and Python: A GuideChoosing Between PHP and Python: A GuideApr 18, 2025 am 12:24 AM

PHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.

PHP and Frameworks: Modernizing the LanguagePHP and Frameworks: Modernizing the LanguageApr 18, 2025 am 12:14 AM

PHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.

PHP's Impact: Web Development and BeyondPHP's Impact: Web Development and BeyondApr 18, 2025 am 12:10 AM

PHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip

How does PHP type hinting work, including scalar types, return types, union types, and nullable types?How does PHP type hinting work, including scalar types, return types, union types, and nullable types?Apr 17, 2025 am 12:25 AM

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values ​​and handle functions that may return null values.

See all articles

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

mPDF

mPDF

mPDF is a PHP library that can generate PDF files from UTF-8 encoded HTML. The original author, Ian Back, wrote mPDF to output PDF files "on the fly" from his website and handle different languages. It is slower than original scripts like HTML2FPDF and produces larger files when using Unicode fonts, but supports CSS styles etc. and has a lot of enhancements. Supports almost all languages, including RTL (Arabic and Hebrew) and CJK (Chinese, Japanese and Korean). Supports nested block-level elements (such as P, DIV),

SecLists

SecLists

SecLists is the ultimate security tester's companion. It is a collection of various types of lists that are frequently used during security assessments, all in one place. SecLists helps make security testing more efficient and productive by conveniently providing all the lists a security tester might need. List types include usernames, passwords, URLs, fuzzing payloads, sensitive data patterns, web shells, and more. The tester can simply pull this repository onto a new test machine and he will have access to every type of list he needs.

VSCode Windows 64-bit Download

VSCode Windows 64-bit Download

A free and powerful IDE editor launched by Microsoft

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

MantisBT

MantisBT

Mantis is an easy-to-deploy web-based defect tracking tool designed to aid in product defect tracking. It requires PHP, MySQL and a web server. Check out our demo and hosting services.