PHP implements plug-in pluggable Design Based on reflection mechanism.

PHP implements plug-in pluggable Design Based on reflection mechanism.

This article describes the pluggable Design of PHP plug-ins Based on the reflection mechanism. We will share this with you for your reference. The details are as follows:

Friends who say PHP is equivalent to ASP can stop it. PHP supports reflection and is still very powerful. Now, let's start today's topic.

Function Description:

The page has a main navigation menu with several default connections.
The plug-in is stored in a directory. After the plug-in is loaded, it automatically adds the required link to the navigation menu.
Some operations can be performed when the plug-in is loaded.
You do not need to change the code when adding or deleting a plug-in dynamically.

Final effect:

Home Page, plug-in 1, plug-in 2

"Homepage" is a menu item that comes with the system. Plug-in 1 and plug-in 2 are menu items registered by the plug-in.

Implementation process:

1. File structure

Learn
Plugin
Plugin1.php
Plugin2.php
Test. php

After this design, the page entry is test. php, And the plug-ins are stored in the plugin directory. You only need to traverse the plugin directory to find all the plug-ins.

2. design the plug-in Interface

interface IPlugin{static function getname();static function init();static function getMenu();}

3. Internal implementation interface of the plug-in

Plugin1 implementation interface:

<? PhpClass Welcome implements IPlugin {static function getname () {return 'Welcome (Plugin) ';} static function getMenu () {return array ('text' => 'plug-In 1 ′, 'href '=> 'HTTP: // www.google.com');} static function init () {echo self: getname (). "loading... <Br/> ";}}?>

Plugin2 implementation interface:

<? PhpClass ShowAD implements IPlugin {static function getname () {return 'show AD (Plugin) ';} static function getMenu () {return array ('text' => 'plug-In 2 ′, 'href '=> 'HTTP: // www.live.com');} static function init () {echo self: getname (). "loading... <Br/> ";}}?>

4. initialize the main navigation menu on the home page

$ Menu [] = array ('text' => 'homepage', 'href '=>'/test. php ');

5. traverse the plug-in directory and load all plug-ins

$pluginPath = $_SERVER['DOCUMENT_ROOT'] . '/plugin';$dirHd = opendir($pluginPath);while ($file = readdir($dirHd)){$pluginFilePath = $pluginPath . '/' . $file;if($file!='.' && $file!='..' && is_file($pluginFilePath)){include "$pluginFilePath";}}

6. filter out the plug-ins that implement the IPlugin interface and execute the plug-in injection operation.

// Reflection execution method (injection menu) foreach (get_declared_classes () as $ class) {$ refClass = new ReflectionClass ($ class ); if ($ refClass-> implementsInterface ('iplugin ') {// plug-in Initialization $ refClass-> getMethod ('init')-> invoke (null ); // get the injection menu $ menuItem = $ refClass-> getMethod ('getmenu ')-> invoke (null); // merge menu items $ menu = array_merge ($ menu, array ($ menuItem ));}}

7. HTML of the output menu on the home page

foreach ($menu as $m){echo "<a href='{$m['href']}'>{$m['text']}</a> ";}

Note that the first part is the PHP reflection operation. Is it very easy. When analyzing the code, there are only two lines of code for a complete reflection operation!

$refClass = new ReflectionClass($class);$menuItem = $refClass->getMethod('getMenu')->invoke(null);

Now, we will introduce the basic functions of reflection. Of course, PHP's reflection function is not just that. If you are interested, explore it yourself.