Table of Contents
2. The use of reflection
3. Specific application examples of reflection-taking an implementation example of the CI framework
Method 1. Writing without reflection:
Method 2. Implementation within the CI framework
4. Summary
Home Backend Development PHP Tutorial PHP advanced features-detailed examples of reflection

PHP advanced features-detailed examples of reflection

Jul 01, 2017 am 10:47 AM
php Example Detailed explanation

1. What is reflection?

It refers to extending the analysis of PHP programs in the PHP running state, exporting or extracting detailed information about classes, methods, properties, parameters, etc., including Comment . This function of dynamically obtaining information and dynamically calling methods of objects is called reflection API.
Reflection is an API for manipulating the metamodel in the Object-oriented paradigm. Its function is very powerful and can help us build complex and scalable applications.

2. The use of reflection

Its uses include: Automatically loadingplug-ins, automatically generating documents, and can even be used to expand the PHP language.

3. Specific application examples of reflection-taking an implementation example of the CI framework

The reflection function is very powerful, so how to use it specifically? What are the application scenarios? Take the CI_Upload class of the CI framework to illustrate. (After searching ReflectionClass globally, I only found that reflection is useful here.)

The core logic of this method is that the caller passes a $config array when instantiating CI_Upload, and all configurations in the array are stored in the method. Assign the value to the corresponding class member attribute (if the attribute has a corresponding set_* method, call the set_* method)

Method 1. Writing without reflection:

public function initialize(array $config = array(), $reset = TRUE){
    $reflection = new ReflectionClass($this);
...    #遍历config,如果存在set_方法调用set方法,没有则直接赋值
    foreach ($config as $key => $v) {        if (method_exists($this, 'set_' . $key)) {            $this->{'set_' . $key}($v);
        }else{            $this->$key =$v;
        }
    }
...
Copy after login

This method has disadvantages : It is impossible to determine whether all the keys in the config array are legal and whether they are member attributes of the class
The judgment can be achieved using reflection.
The benefit of reflection here is that it can determine whether a class has properties (hasProperty) and whether a class has methods (hasMethod).

Method 2. Implementation within the CI framework

D:\project\app\system\libraries\Upload.php/**
 * Initialize preferences
 *
 * @param   array   $config
 * @param   bool    $reset
 * @return  CI_Upload
 */public function initialize(array $config = array(), $reset = TRUE){
    $reflection = new ReflectionClass($this);
...    foreach ($config as $key => &$value)
    {        if ($key[0] !== '_' && $reflection->hasProperty($key))
        {            if ($reflection->hasMethod('set_'.$key))
            {                $this->{'set_'.$key}($value);
            }            else
            {                $this->$key = $value;
            }
        }
    }
...
Copy after login

4. Summary

Regarding reflection (whether it is a reflection class (ReflectionClass) or a reflection function ReflectionFunction, it is actually a class and a function (difference) just remember one thing: reflection class/function can obtain all information about the class, including:
- basic information of the class (class name, whether it is an abstract class, whether it can be instantiated, whether the class is final or abstract)
- Class methods, whether the method exists, method return value, method annotation, Method Names
- Class attributes, static attributes, constants
- Location namespace Namespace

If you have the above situation, you might as well use reflection to solve it:)

The above is the detailed content of PHP advanced features-detailed examples of reflection. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
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

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

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

CakePHP Project Configuration CakePHP Project Configuration Sep 10, 2024 pm 05:25 PM

In this chapter, we will understand the Environment Variables, General Configuration, Database Configuration and Email Configuration in CakePHP.

PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

CakePHP Date and Time CakePHP Date and Time Sep 10, 2024 pm 05:27 PM

To work with date and time in cakephp4, we are going to make use of the available FrozenTime class.

CakePHP File upload CakePHP File upload Sep 10, 2024 pm 05:27 PM

To work on file upload we are going to use the form helper. Here, is an example for file upload.

CakePHP Routing CakePHP Routing Sep 10, 2024 pm 05:25 PM

In this chapter, we are going to learn the following topics related to routing ?

Discuss CakePHP Discuss CakePHP Sep 10, 2024 pm 05:28 PM

CakePHP is an open-source framework for PHP. It is intended to make developing, deploying and maintaining applications much easier. CakePHP is based on a MVC-like architecture that is both powerful and easy to grasp. Models, Views, and Controllers gu

How To Set Up Visual Studio Code (VS Code) for PHP Development How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

CakePHP Creating Validators CakePHP Creating Validators Sep 10, 2024 pm 05:26 PM

Validator can be created by adding the following two lines in the controller.

See all articles