rfc:splclassloader

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rfc:splclassloader [2011/11/08 02:41] – [Extended Rules for Proposal] Added include_path option guilhermeblancorfc:splclassloader [2012/06/29 06:53] – laruence
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 Even though PSR-0 is strict, PHP cannot force php extension. Ideally, the file extension is customizable, but default approach would be the defined one in PSR-0. Even though PSR-0 is strict, PHP cannot force php extension. Ideally, the file extension is customizable, but default approach would be the defined one in PSR-0.
  
-===== Usage Examples =====+===== Initial missing support ===== 
 + 
 +PHP does not provide a single approach for any OO based autoloader, so initially a new interface is required, for anyone interested to implement their own Autoloader. From now on, let's name it as SplAutoloader. 
 +The purpose of this interface is to bring the minimum contract that any interested to autoload their resources should follow.  
 +Here is the proposed implementation: 
 + 
 +<code php> 
 +/** 
 + * SplAutoloader defines the contract that any OO based autoloader must follow. 
 + * 
 + * @author Guilherme Blanco <guilhermeblanco@php.net> 
 + */ 
 +interface SplAutoloader 
 +{ 
 +    /** 
 +     * Defines autoloader to work silently if resource is not found. 
 +     * 
 +     * @const 
 +     */ 
 +    const MODE_SILENT = 0; 
 +     
 +    /** 
 +     * Defines autoloader to work normally (requiring an un-existent resource). 
 +     * 
 +     * @const 
 +     */ 
 +    const MODE_NORMAL = 1; 
 +     
 +    /** 
 +     * Defines autoloader to work in debug mode, loading file and validating requested resource. 
 +     * 
 +     * @const 
 +     */ 
 +    const MODE_DEBUG = 2; 
 +     
 +    /** 
 +     * Define the autoloader work mode. 
 +     * 
 +     * @param integer $mode Autoloader work mode. 
 +     */ 
 +    public function setMode($mode); 
 +     
 +    /** 
 +     * Add a new resource lookup path. 
 +     * 
 +     * @param string $resourceName Resource name, namespace or prefix. 
 +     * @param mixed $resourcePath Resource single path or multiple paths (array). 
 +     */ 
 +    public function add($resourceName, $resourcePath = null); 
 +     
 +    /** 
 +     * Load a resource through provided resource name. 
 +     * 
 +     * @param string $resourceName Resource name. 
 +     */ 
 +    public function load($resourceName); 
 +     
 +    /** 
 +     * Register this as an autoloader instance. 
 +     * 
 +     * @param boolean Whether to prepend the autoloader or not in autoloader's list. 
 +     */ 
 +    public function register($prepend = false); 
 +     
 +    /** 
 +     * Unregister this autoloader instance. 
 +     * 
 +     */ 
 +    public function unregister(); 
 +} 
 +</code> 
 + 
 +===== Examples of Namespace Resolution =====
  
 The standards we set here should be the lowest common denominator for painless autoloader interoperability. You can test that you are following these standards by utilizing this sample SplClassLoader implementation which is able to load PHP 5.3 classes. The standards we set here should be the lowest common denominator for painless autoloader interoperability. You can test that you are following these standards by utilizing this sample SplClassLoader implementation which is able to load PHP 5.3 classes.
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     * /path/to/project/lib/vendor/namespace/package_name/Class/Name.php     * /path/to/project/lib/vendor/namespace/package_name/Class/Name.php
  
-===== Example implementation =====+===== Examples of usage ===== 
 + 
 +Autoloading Doctrine 2: 
 + 
 +<code php> 
 +$classLoader = new \SplClassLoader(); // $mode is "normal" 
 +$classLoader->add('Doctrine', array( 
 +    '/path/to/doctrine-common', '/path/to/doctrine-dbal', '/path/to/doctrine-orm' 
 +)); 
 +$classLoader->register(true); // Autoloader is prepended 
 +</code>  
 + 
 +Autoloading PEAR1: 
 + 
 +<code php> 
 +$classLoader = new \SplClassLoader(); 
 +$classLoader->setMode(\SplClassLoader::MODE_SILENT); 
 +$classLoader->setIncludePathLookup(true); 
 +$classLoader->add('PEAR'); 
 +$classLoader->register(); 
 +</code> 
 + 
 +Autoloading in debug mode: 
 + 
 +<code php> 
 +$classLoader = new \SplClassLoader(); 
 +$classLoader->setMode(\SplClassLoader::MODE_NORMAL | \SplClassLoader::MODE_DEBUG); 
 +$classLoader->add('Symfony', '/path/to/symfony'); 
 +$classLoader->add('Zend', '/path/to/zf'); 
 +$classLoader->register(); 
 +</code> 
 + 
 +===== Example of simplest implementation =====
  
 Below is an example function to simply demonstrate how the above proposed standards are autoloaded. Below is an example function to simply demonstrate how the above proposed standards are autoloaded.
Line 84: Line 188:
  
 The following class is a sample SplClassLoader implementation that can load your classes if you follow the autoloader interoperability standards proposed above. It is the current recommended way to load PHP 5.3 classes that follow these standards. The following class is a sample SplClassLoader implementation that can load your classes if you follow the autoloader interoperability standards proposed above. It is the current recommended way to load PHP 5.3 classes that follow these standards.
- 
-> NOTE: This implementation is not the proposed final. It requires two updates: 
->   * Multiple paths per namespace 
->   * Silent mode 
  
 <code php> <code php>
-<?php 
- 
 /** /**
  * SplClassLoader implementation that implements the technical interoperability  * SplClassLoader implementation that implements the technical interoperability
  * standards for PHP 5.3 namespaces and class names.  * standards for PHP 5.3 namespaces and class names.
  *  *
- * http://groups.google.com/group/php-standards/web/final-proposal+ * https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-0.md 
 + * 
 + * Example usage: 
 + * 
 + *     $classLoader = new \SplClassLoader(); 
 + * 
 + *     // Configure the SplClassLoader to act normally or silently 
 + *     $classLoader->setMode(\SplClassLoader::MODE_NORMAL); 
 + * 
 + *     // Add a namespace of classes 
 + *     $classLoader->add('Doctrine', array( 
 + *         '/path/to/doctrine-common', '/path/to/doctrine-dbal', '/path/to/doctrine-orm' 
 + *     )); 
 + * 
 + *     // Add a prefix 
 + *     $classLoader->add('Swift', '/path/to/swift'); 
 + * 
 + *     // Add a prefix through PEAR1 convention, requiring include_path lookup 
 + *     $classLoader->add('PEAR'); 
 + * 
 + *     // Allow to PHP use the include_path for file path lookup 
 + *     $classLoader->setIncludePathLookup(true); 
 + * 
 + *     // Possibility to change the default php file extension 
 + *     $classLoader->setFileExtension('.php');
  *  *
- * // Example which loads classes for the Doctrine Common package in the + *     // Register the autoloader, prepending it in the stack 
- * // Doctrine\Common namespace. + *     $classLoader->register(true);
- * $classLoader = new SplClassLoader('Doctrine\Common', '/path/to/doctrine'); +
- * $classLoader->register();+
  *  *
 + * @author Guilherme Blanco <guilhermeblanco@php.net>
  * @author Jonathan H. Wage <jonwage@gmail.com>  * @author Jonathan H. Wage <jonwage@gmail.com>
  * @author Roman S. Borschel <roman@code-factory.org>  * @author Roman S. Borschel <roman@code-factory.org>
Line 109: Line 230:
  * @author Fabien Potencier <fabien.potencier@symfony-project.org>  * @author Fabien Potencier <fabien.potencier@symfony-project.org>
  */  */
-class SplClassLoader+class SplClassLoader implements SplAutoloader
 { {
-    private $_fileExtension = '.php'; +    /** 
-    private $_namespace; +     * @var string 
-    private $_includePath; +     */ 
-    private $_namespaceSeparator = '\\';+    private $fileExtension = '.php'; 
 +     
 +    /** 
 +     * @var boolean 
 +     */ 
 +    private $includePathLookup = false; 
 +     
 +    /** 
 +     * @var array 
 +     */ 
 +    private $resources = array(); 
 +     
 +    /** 
 +     * @var integer 
 +     */ 
 +    private $mode = self::MODE_NORMAL;
  
     /**     /**
-     * Creates a new <tt>SplClassLoader</tt> that loads classes of the +     * {@inheritdoc}
-     * specified namespace. +
-     * +
-     * @param string $ns The namespace to use.+
      */      */
-    public function __construct($ns = null, $includePath = null)+    public function setMode($mode)
     {     {
-        $this->_namespace = $ns; +    if ($mode & self::MODE_SILENT && $mode & self::MODE_NORMAL) { 
-        $this->_includePath = $includePath;+        throw new \InvalidArgumentException( 
 +            sprintf('Cannot have %s working normally and silently at the same time!', __CLASS__) 
 +        ); 
 +    } 
 +     
 +        $this->mode = $mode;
     }     }
 + 
     /**     /**
-     * Sets the namespace separator used by classes in the namespace of this class loader.+     * Define the file extension of resource files in the path of this class loader.
      *      *
-     * @param string $sep The separator to use.+     * @param string $fileExtension
      */      */
-    public function setNamespaceSeparator($sep)+    public function setFileExtension($fileExtension)
     {     {
-        $this->_namespaceSeparator = $sep;+        $this->fileExtension = $fileExtension;
     }     }
 + 
     /**     /**
-     * Gets the namespace seperator used by classes in the namespace of this class loader.+     * Retrieve the file extension of resource files in the path of this class loader.
      *      *
-     * @return void+     * @return string
      */      */
-    public function getNamespaceSeparator()+    public function getFileExtension()
     {     {
-        return $this->_namespaceSeparator;+        return $this->fileExtension;
     }     }
 + 
     /**     /**
-     * Sets the base include path for all class files in the namespace of this class loader.+     * Turns on searching the include for class files. Allows easy loading installed PEAR packages.
      *      *
-     * @param string $includePath+     * @param boolean $includePathLookup
      */      */
-    public function setIncludePath($includePath)+    public function setIncludePathLookup($includePathLookup)
     {     {
-        $this->_includePath = $includePath;+        $this->includePathLookup = $includePathLookup;
     }     }
 + 
     /**     /**
      * Gets the base include path for all class files in the namespace of this class loader.      * Gets the base include path for all class files in the namespace of this class loader.
      *      *
-     * @return string $includePath+     * @return boolean
      */      */
-    public function getIncludePath()+    public function getIncludePathLookup()
     {     {
-        return $this->_includePath;+        return $this->includePathLookup;
     }     }
 + 
     /**     /**
-     * Sets the file extension of class files in the namespace of this class loader. +     * {@inheritdoc}
-     * +
-     * @param string $fileExtension+
      */      */
-    public function setFileExtension($fileExtension)+    public function register($prepend = false)
     {     {
-        $this->_fileExtension = $fileExtension;+        spl_autoload_register(array($this, 'load'), true, $prepend);
     }     }
 + 
     /**     /**
-     * Gets the file extension of class files in the namespace of this class loader. +     * {@inheritdoc}
-     * +
-     * @return string $fileExtension+
      */      */
-    public function getFileExtension()+    public function unregister()
     {     {
-        return $this->_fileExtension;+        spl_autoload_unregister(array($this, 'load'));
     }     }
 +    
     /**     /**
-     * Installs this class loader on the SPL autoload stack.+     * {@inheritdoc}
      */      */
-    public function register()+    public function add($resource, $resourcePath = null)
     {     {
-        spl_autoload_register(array($this, 'loadClass'));+        $this->resources[$resource] = (array) $resourcePath;
     }     }
 +    
     /**     /**
-     * Uninstalls this class loader from the SPL autoloader stack.+     * {@inheritdoc}
      */      */
-    public function unregister()+    public function load($resourceName)
     {     {
-        spl_autoload_unregister(array($this, 'loadClass'));+        $resourceAbsolutePath = $this->getResourceAbsolutePath($resourceName); 
 +         
 +        switch (true) { 
 +            case ($this->mode & self::MODE_SILENT): 
 +                if ($resourceAbsolutePath !== false) { 
 +                    require $resourceAbsolutePath; 
 +                } 
 +                break; 
 +         
 +            case ($this->mode & self::MODE_NORMAL): 
 +            default: 
 +                require $resourceAbsolutePath; 
 +                break; 
 +        } 
 +         
 +        if ($this->mode & self::MODE_DEBUG && ! $this->isResourceDeclared($resourceName)) { 
 +            throw new \RuntimeException( 
 +                sprintf('Autoloader expected resource "%s" to be declared in file "%s".', $resourceName, $resourceAbsolutePath) 
 +            ); 
 +        }
     }     }
 +    
     /**     /**
-     * Loads the given class or interface.+     * Transform resource name into its absolute resource path representation.
      *      *
-     * @param string $className The name of the class to load. +     * @params string $resourceName 
-     * @return void+     * 
 +     * @return string Resource absolute path.
      */      */
-    public function loadClass($className)+    private function getResourceAbsolutePath($resourceName)
     {     {
-        if (null === $this->_namespace || $this->_namespace . $this->_namespaceSeparator === substr($className, 0, strlen($this->_namespace . $this->_namespaceSeparator))) { +        $resourceRelativePath = $this->getResourceRelativePath($resourceName); 
-            $fileName = ''; +         
-            $namespace = ''; +        foreach ($this->resources as $resource => $resourcesPath) { 
-            if (false !== ($lastNsPos = strripos($className, $this->_namespaceSeparator))) { +            if (strpos($resourceName, $resource) !== 0) { 
-                $namespace = substr($className, 0, $lastNsPos); +                continue; 
-                $className = substr($className, $lastNsPos + 1); +            } 
-                $fileName = str_replace($this->_namespaceSeparator, DIRECTORY_SEPARATOR, $namespace) . DIRECTORY_SEPARATOR;+             
 +            foreach ($resourcesPath as $resourcePath) { 
 +                $resourceAbsolutePath = $resourcePath . DIRECTORY_SEPARATOR . $resourceRelativePath; 
 +                 
 +                if (is_file($resourceAbsolutePath)) { 
 +                    return $resourceAbsolutePath; 
 +                }
             }             }
-            $fileName .= str_replace('_', DIRECTORY_SEPARATOR, $className) . $this->_fileExtension; 
- 
-            require ($this->_includePath !== null ? $this->_includePath . DIRECTORY_SEPARATOR : '') . $fileName; 
         }         }
 +        
 +        if ($this->includePathLookup && ($resourceAbsolutePath = stream_resolve_include_path($resourceRelativePath)) !== false) {
 +            return $resourceAbsolutePath;
 +        }
 +        
 +        return false;
 +    }
 +    
 +    /**
 +     * Transform resource name into its relative resource path representation.
 +     *
 +     * @params string $resourceName
 +     *
 +     * @return string Resource relative path.
 +     */
 +    private function getResourceRelativePath($resourceName)
 +    {
 +        // We always work with FQCN in this context
 +        $resourceName = ltrim($resourceName, '\\');
 +        $resourcePath = '';
 +        
 +        if (($lastNamespacePosition = strrpos($resourceName, '\\')) !== false) {
 +            // Namespaced resource name
 +            $resourceNamespace = substr($resourceName, 0, $lastNamespacePosition);
 +            $resourceName      = substr($resourceName, $lastNamespacePosition + 1);
 +            $resourcePath      =  str_replace('\\', DIRECTORY_SEPARATOR, $resourceNamespace) . DIRECTORY_SEPARATOR;
 +        }
 +        
 +        return $resourcePath . str_replace('_', DIRECTORY_SEPARATOR . $resourceName) . $this->fileExtension;
 +    }
 +    
 +    /**
 +     * Check if resource is declared in user space.
 +     *
 +     * @params string $resourceName
 +     *
 +     * @return boolean
 +     */
 +    private function isResourceDeclared($resourceName)
 +    {
 +    return class_exists($resourceName, false) 
 +        || interface_exists($resourceName, false) 
 +        || (function_exists('trait_exists') && trait_exists($resourceName, false));
     }     }
 } }
 </code> </code>
  
-===== Example usage ===== +If any interested wants to customize the public methods, like caching through APC to reduce I/O, it should be possible to extend SplClassLoader and overwrite the public methods.
- +
-<code php> +
-$classLoader = new SplClassLoader(\SplClassLoader::MODE_SILENT); +
-$classLoader->setFileExtension('.php'); +
-$classLoader->registerNamespace( +
-    'Doctrine\Common',  +
-    array('/path/to/doctrine', '/path/to/another/folder/with/doctrine') +
-); // Namespace style +
-$classLoader->registerPrefix('PEAR_', '/path/to/pear'); // PEAR style +
-$classLoader->register(); +
-</code>+
  
 ===== Proposal and Patch ===== ===== Proposal and Patch =====
Line 251: Line 440:
 Main purpose of this proposal is to support both PEAR style directory organization and also Namespace directory organization. Main purpose of this proposal is to support both PEAR style directory organization and also Namespace directory organization.
  
-===== Implementation extension =====+===== Changelog =====
  
-According to new threads in php-standards list, it seems all derived implementations have included these extensions to original support: +  * 2011-11-09 Christian Kaps: Update examples to use the new interface(setMode) 
-  * Multiple paths per namespace +  * 2011-11-08 Guilherme Blanco: Removed constructor prototype and created setMode. 
-  * Silent mode as a flag +  * 2011-11-08 Guilherme Blanco: Updated SplClassLoader implementation.
- +
-This turns the RFC specification incompatible with current patch. Patch is going to be updated as soon as voting ends. +
- +
-===== Changelog =====+
   * 2011-11-07 Guilherme Blanco: Expanded extended rules.   * 2011-11-07 Guilherme Blanco: Expanded extended rules.
   * 2011-10-25 David Coallier: Added the new SPL patch information and feature request link.   * 2011-10-25 David Coallier: Added the new SPL patch information and feature request link.
Line 265: Line 450:
   * 2010-03-22 Guilherme Blanco: Initial RFC creation.   * 2010-03-22 Guilherme Blanco: Initial RFC creation.
  
 +===== Comments =====
 +  * laruence : I have already got a similar loader implemented in Yaf, called Yaf_Loader, you can found the source here: [[http://svn.php.net/viewvc/pecl/yaf/trunk/yaf_loader.c?view=markup]]
rfc/splclassloader.txt · Last modified: 2017/09/22 13:28 by 127.0.0.1

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