note 116280 added to language.namespaces.rationale

To people coming here by searching about namespaces, know that a consortium has studied about best practices in PHP, in order to allow developers to have common coding standards. These best practices are called "PHP Standard Recommendations" , also known as PSR. They are visible on this link : http://www.php-fig.org/psr Actually there are 5 coding standards categories : PSR-0 : Autoloading Standard , which goal is to make the use of Namespaces easier, in order to convert a namespace into a file path. PSR-1 : Basic Coding Standard , basically, standards :) PSR-2 : Coding Style Guide, where to put braces, how to write a class, etc. PSR-3 : Logger Interface , how to write a standard logger PSR-4 : Improved Autoloading , to resolve more Namespaces into paths. The ones I want to point are PSR-0 and PSR-4 : they use namespaces to resolve a FQCN (Fully qualified class name = full namespace + class name) into a file path. Basic example, you have this directory structure : ./src/Pierstoval/Tools/MyTool.php The namespacing PSR-0 or PSR-4 standard tells that you can transform this path into a FQCN. Read the principles of autoload if you need to know what it means, because it's almost mandatory ;) . Structure : {path}/autoloader.php {path}/index.php {path}/src/Pierstoval/Tools/MyTool.php Files : <?php // {path}/index.php include 'autoloader.php'; $tool = new Pierstoval/Tools/MyTool(); ?> <?php // {path}/src/Pierstoval/Tools/MyTool.php namespace Pierstoval\Tools; class MyTool {} ?> <?php // {path}/autoloader.php function loadClass($className) { $fileName = ''; $namespace = ''; // Sets the include path as the "src" directory $includePath = dirname(__FILE__).DIRECTORY_SEPARATOR.'src'; if (false !== ($lastNsPos = strripos($className, '\\'))) { $namespace = substr($className, 0, $lastNsPos); $className = substr($className, $lastNsPos + 1); $fileName = str_replace('\\', DIRECTORY_SEPARATOR, $namespace) . DIRECTORY_SEPARATOR; } $fileName .= str_replace('_', DIRECTORY_SEPARATOR, $className) . '.php'; $fullFileName = $includePath . DIRECTORY_SEPARATOR . $fileName; if (file_exists($fullFileName)) { require $fullFileName; } else { echo 'Class "'.$className.'" does not exist.'; } } spl_autoload_register('loadClass'); // Registers the autoloader ?> A standardized autoloader will get the class you want to instanciate (MyTool) and get the FQCN, transform it into a file path, and check if the file exists. If it does, it will <?php include(); ?> it, and if you wrote your class correctly, the class will be available within its correct namespace. Then, if you have the following code : <?php $tool = new Pierstoval/Tools/MyTool(); ?> The autoloader will transform the FQCN into this path : {path}/src/Pierstoval/Tools/MyTool.php This might be the best practices ever in PHP framework developments, such as Symfony or others. ---- Server IP: 72.52.91.14 Probable Submitter: 192.196.142.21 ---- Manual Page -- http://php.net/manual/en/language.namespaces.rationale.php Edit -- https://master.php.net/note/edit/116280 Del: integrated -- https://master.php.net/note/delete/116280/integrated Del: useless -- https://master.php.net/note/delete/116280/useless Del: bad code -- https://master.php.net/note/delete/116280/bad+code Del: spam -- https://master.php.net/note/delete/116280/spam Del: non-english -- https://master.php.net/note/delete/116280/non-english Del: in docs -- https://master.php.net/note/delete/116280/in+docs Del: other reasons-- https://master.php.net/note/delete/116280 Reject -- https://master.php.net/note/reject/116280 Search -- https://master.php.net/manage/user-notes.php