PHP instantiate_class函数代码示例

/**
* Class registry
*
* This function acts as a singleton.  If the requested class does not
* exist it is instantiated and set to a static variable.  If it has
* previously been instantiated the variable is returned.
*
* @access	public
* @param	string	the class name being requested
* @param	bool	optional flag that lets classes get loaded but not instantiated
* @return	object
*/
function &load_class($class, $instantiate = TRUE)
{
    static $objects = array();
    // Does the class exist?  If so, we're done...
    if (isset($objects[$class])) {
        return $objects[$class];
    }
    // If the requested class does not exist in the application/libraries
    // folder we'll load the native class from the system/libraries folder.
    if (file_exists(APPPATH . 'libraries/' . config_item('subclass_prefix') . $class . EXT)) {
        require BASEPATH . 'libraries/' . $class . EXT;
        require APPPATH . 'libraries/' . config_item('subclass_prefix') . $class . EXT;
        $is_subclass = TRUE;
    } else {
        if (file_exists(APPPATH . 'libraries/' . $class . EXT)) {
            require APPPATH . 'libraries/' . $class . EXT;
            $is_subclass = FALSE;
        } else {
            require BASEPATH . 'libraries/' . $class . EXT;
            $is_subclass = FALSE;
        }
    }
    if ($instantiate == FALSE) {
        $objects[$class] = TRUE;
        return $objects[$class];
    }
    if ($is_subclass == TRUE) {
        $name = config_item('subclass_prefix') . $class;
        $objects[$class] =& instantiate_class(new $name());
        return $objects[$class];
    }
    $name = $class != 'Controller' ? 'CI_' . $class : $class;
    $objects[$class] =& instantiate_class(new $name());
    return $objects[$class];
}

 /**
  * Load the Utilities Class
  *
  * @access    public
  * @return    string
  */
 function dbutil()
 {
     if (!class_exists('CI_DB')) {
         $this->database();
     }
     $CI =& get_instance();
     // for backwards compatibility, load dbforge so we can extend dbutils off it
     // this use is deprecated and strongly discouraged
     $CI->load->dbforge();
     require_once BASEPATH . 'database/DB_utility' . EXT;
     require_once BASEPATH . 'database/drivers/' . $CI->db->dbdriver . '/' . $CI->db->dbdriver . '_utility' . EXT;
     $class = 'CI_DB_' . $CI->db->dbdriver . '_utility';
     $CI->dbutil =& instantiate_class(new $class());
     $CI->load->_ci_assign_to_models();
 }

/**
 * Initialize the database
 *
 * @category	Database
 * @author		ExpressionEngine Dev Team
 * @link		http://codeigniter.com/user_guide/database/
 */
function &DB($params = '', $active_record_override = NULL)
{
    // Load the DB config file if a DSN string wasn't passed
    if (is_string($params) and strpos($params, '://') === FALSE) {
        include APPPATH . 'config/database' . EXT;
        if (!isset($db) or count($db) == 0) {
            show_error('No database connection settings were found in the database config file.');
        }
        if ($params != '') {
            $active_group = $params;
        }
        if (!isset($active_group) or !isset($db[$active_group])) {
            show_error('You have specified an invalid database connection group.');
        }
        $params = $db[$active_group];
    } elseif (is_string($params)) {
        /* parse the URL from the DSN string
         *  Database settings can be passed as discreet
         *  parameters or as a data source name in the first
         *  parameter. DSNs must have this prototype:
         *  $dsn = 'driver://username:password@hostname/database';
         */
        if (($dns = @parse_url($params)) === FALSE) {
            show_error('Invalid DB Connection String');
        }
        $params = array('dbdriver' => $dns['scheme'], 'hostname' => isset($dns['host']) ? rawurldecode($dns['host']) : '', 'username' => isset($dns['user']) ? rawurldecode($dns['user']) : '', 'password' => isset($dns['pass']) ? rawurldecode($dns['pass']) : '', 'database' => isset($dns['path']) ? rawurldecode(substr($dns['path'], 1)) : '');
        // were additional config items set?
        if (isset($dns['query'])) {
            parse_str($dns['query'], $extra);
            foreach ($extra as $key => $val) {
                // booleans please
                if (strtoupper($val) == "TRUE") {
                    $val = TRUE;
                } elseif (strtoupper($val) == "FALSE") {
                    $val = FALSE;
                }
                $params[$key] = $val;
            }
        }
    }
    // No DB specified yet?  Beat them senseless...
    if (!isset($params['dbdriver']) or $params['dbdriver'] == '') {
        show_error('You have not selected a database type to connect to.');
    }
    // Load the DB classes.  Note: Since the active record class is optional
    // we need to dynamically create a class that extends proper parent class
    // based on whether we're using the active record class or not.
    // Kudos to Paul for discovering this clever use of eval()
    if ($active_record_override !== NULL) {
        $active_record = $active_record_override;
    }
    require_once BASEPATH . 'database/DB_driver' . EXT;
    if (!isset($active_record) or $active_record == TRUE) {
        require_once BASEPATH . 'database/DB_active_rec' . EXT;
        if (!class_exists('CI_DB')) {
            eval('class CI_DB extends CI_DB_active_record { }');
        }
    } else {
        if (!class_exists('CI_DB')) {
            eval('class CI_DB extends CI_DB_driver { }');
        }
    }
    require_once BASEPATH . 'database/drivers/' . $params['dbdriver'] . '/' . $params['dbdriver'] . '_driver' . EXT;
    // Instantiate the DB adapter
    $driver = 'CI_DB_' . $params['dbdriver'] . '_driver';
    $DB =& instantiate_class(new $driver($params));
    if ($DB->autoinit == TRUE) {
        $DB->initialize();
    }
    return $DB;
}

/**
* Class registry
*
* This function acts as a singleton.  If the requested class does not
* exist it is instantiated and set to a static variable.  If it has
* previously been instantiated the variable is returned.
*
* @access	public
* @param	string	the class name being requested
* @param	bool	optional flag that lets classes get loaded but not instantiated
* @return	object
*/
function &load_class($class, $instantiate = TRUE)
{
    static $objects = array();
    // Does the class exist?  If so, we're done...
    if (isset($objects[$class])) {
        return $objects[$class];
    }
    $subclass_prefix = config_item('subclass_prefix');
    $subclass = APPPATH . "libraries/{$subclass_prefix}{$class}.php";
    $baseclass = BASEPATH . "libraries/{$class}.php";
    // If the requested class does not exist in the application/libraries
    // folder we'll load the native class from the system/libraries folder.
    if (file_exists($subclass)) {
        require $baseclass;
        require $subclass;
        $is_subclass = TRUE;
    } else {
        $overwrite_class = APPPATH . "libraries/{$class}.php";
        if (file_exists($overwrite_class)) {
            require $overwrite_class;
        } else {
            require $baseclass;
        }
        $is_subclass = FALSE;
    }
    if (!$instantiate) {
        $objects[$class] = TRUE;
        return $objects[$class];
    }
    if ($is_subclass == TRUE) {
        $name = $subclass_prefix . $class;
        $objects[$class] =& instantiate_class(new $name());
        return $objects[$class];
    }
    $name = $class != 'Controller' ? 'CI_' . $class : $class;
    $objects[$class] =& instantiate_class(new $name());
    return $objects[$class];
}

/**
* Class registry
*
* This function acts as a singleton.  If the requested class does not
* exist it is instantiated and set to a static variable.  If it has
* previously been instantiated the variable is returned.
*
* @access	public
* @param	string	the class name being requested
* @param	string	the directory where the class should be found
* @param	string	the class name prefix
* @return	object
*/
function &load_class($class, $directory = 'libraries', $prefix = 'CI_')
{
    static $_classes = array();
    // Does the class exist?  If so, we're done...
    if (isset($_classes[$class])) {
        return $_classes[$class];
    }
    $name = FALSE;
    // Look for the class first in the native system/libraries folder
    // thenin the local application/libraries folder
    foreach (array(BASEPATH, APPPATH) as $path) {
        if (file_exists($path . $directory . '/' . $class . EXT)) {
            $name = $prefix . $class;
            if (class_exists($name) === FALSE) {
                require $path . $directory . '/' . $class . EXT;
            }
            break;
        }
    }
    // Is the request a class extension?  If so we load it too
    if (file_exists(APPPATH . $directory . '/' . config_item('subclass_prefix') . $class . EXT)) {
        $name = config_item('subclass_prefix') . $class;
        if (class_exists($name) === FALSE) {
            require APPPATH . $directory . '/' . config_item('subclass_prefix') . $class . EXT;
        }
    }
    // Did we find the class?
    if ($name === FALSE) {
        // Note: We use exit() rather then show_error() in order to avoid a
        // self-referencing loop with the Excptions class
        exit('Unable to locate the specified class: ' . $class . EXT);
    }
    // Keep track of what we just loaded
    is_loaded($class);
    $_classes[$class] =& instantiate_class(new $name());
    return $_classes[$class];
}

 /**
  * Load the Utilities Class
  *
  * @return	string
  */
 public function dbutil()
 {
     if (class_exists('CI_DB_utility')) {
         return;
     }
     if (!class_exists('CI_DB')) {
         $this->database();
     }
     require BASEPATH . 'database/DB_utility.php';
     require BASEPATH . "database/drivers/{$this->CI->db->dbdriver}/{$this->CI->db->dbdriver}_utility.php";
     $class = 'CI_DB_' . $this->CI->db->dbdriver . '_utility';
     $this->CI->dbutil =& instantiate_class(new $class());
     $this->CI->load->_ci_assign_to_models();
 }

 function sanitize($data, $type, $base = '')
 {
     $data = trim($data);
     if ($data !== '' || $type & SIMPLEPIE_CONSTRUCT_IRI) {
         if ($type & SIMPLEPIE_CONSTRUCT_MAYBE_HTML) {
             if (preg_match('/(&(#(x[0-9a-fA-F]+|[0-9]+)|[a-zA-Z0-9]+)|<\\/[A-Za-z][^\\x09\\x0A\\x0B\\x0C\\x0D\\x20\\x2F\\x3E]*' . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . '>)/', $data)) {
                 $type |= SIMPLEPIE_CONSTRUCT_HTML;
             } else {
                 $type |= SIMPLEPIE_CONSTRUCT_TEXT;
             }
         }
         if ($type & SIMPLEPIE_CONSTRUCT_BASE64) {
             $data = base64_decode($data);
         }
         if ($type & SIMPLEPIE_CONSTRUCT_XHTML) {
             if ($this->remove_div) {
                 $data = preg_replace('/^<div' . SIMPLEPIE_PCRE_XML_ATTRIBUTE . '>/', '', $data);
                 $data = preg_replace('/<\\/div>$/', '', $data);
             } else {
                 $data = preg_replace('/^<div' . SIMPLEPIE_PCRE_XML_ATTRIBUTE . '>/', '<div>', $data);
             }
         }
         if ($type & (SIMPLEPIE_CONSTRUCT_HTML | SIMPLEPIE_CONSTRUCT_XHTML)) {
             // Strip comments
             if ($this->strip_comments) {
                 $data = SimplePie_Misc::strip_comments($data);
             }
             // Strip out HTML tags and attributes that might cause various security problems.
             // Based on recommendations by Mark Pilgrim at:
             // http://diveintomark.org/archives/2003/06/12/how_to_consume_rss_safely
             if ($this->strip_htmltags) {
                 foreach ($this->strip_htmltags as $tag) {
                     $pcre = "/<({$tag})" . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . "(>(.*)<\\/{$tag}" . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . '>|(\\/)?>)/siU';
                     while (preg_match($pcre, $data)) {
                         $data = preg_replace_callback($pcre, array(&$this, 'do_strip_htmltags'), $data);
                     }
                 }
             }
             if ($this->strip_attributes) {
                 foreach ($this->strip_attributes as $attrib) {
                     $data = preg_replace('/(<[A-Za-z][^\\x09\\x0A\\x0B\\x0C\\x0D\\x20\\x2F\\x3E]*)' . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . trim($attrib) . '(?:\\s*=\\s*(?:"(?:[^"]*)"|\'(?:[^\']*)\'|(?:[^\\x09\\x0A\\x0B\\x0C\\x0D\\x20\\x22\\x27\\x3E][^\\x09\\x0A\\x0B\\x0C\\x0D\\x20\\x3E]*)?))?' . SIMPLEPIE_PCRE_HTML_ATTRIBUTE . '>/', '\\1\\2\\3>', $data);
                 }
             }
             // Replace relative URLs
             $this->base = $base;
             foreach ($this->replace_url_attributes as $element => $attributes) {
                 $data = $this->replace_urls($data, $element, $attributes);
             }
             // If image handling (caching, etc.) is enabled, cache and rewrite all the image tags.
             if (isset($this->image_handler) && (string) $this->image_handler !== '' && $this->enable_cache) {
                 $images = SimplePie_Misc::get_element('img', $data);
                 foreach ($images as $img) {
                     if (isset($img['attribs']['src']['data'])) {
                         $image_url = call_user_func($this->cache_name_function, $img['attribs']['src']['data']);
                         $cache = call_user_func(array($this->cache_class, 'create'), $this->cache_location, $image_url, 'spi');
                         if ($cache->load()) {
                             $img['attribs']['src']['data'] = $this->image_handler . $image_url;
                             $data = str_replace($img['full'], SimplePie_Misc::element_implode($img), $data);
                         } else {
                             $file =& instantiate_class(new $this->file_class($img['attribs']['src']['data'], $this->timeout, 5, array('X-FORWARDED-FOR' => $_SERVER['REMOTE_ADDR']), $this->useragent, $this->force_fsockopen));
                             $headers = $file->headers;
                             if ($file->success && ($file->method & SIMPLEPIE_FILE_SOURCE_REMOTE === 0 || ($file->status_code === 200 || $file->status_code > 206 && $file->status_code < 300))) {
                                 if ($cache->save(array('headers' => $file->headers, 'body' => $file->body))) {
                                     $img['attribs']['src']['data'] = $this->image_handler . $image_url;
                                     $data = str_replace($img['full'], SimplePie_Misc::element_implode($img), $data);
                                 } else {
                                     trigger_error("{$this->cache_location} is not writeable", E_USER_WARNING);
                                 }
                             }
                         }
                     }
                 }
             }
             // Having (possibly) taken stuff out, there may now be whitespace at the beginning/end of the data
             $data = trim($data);
         }
         if ($type & SIMPLEPIE_CONSTRUCT_IRI) {
             $data = SimplePie_Misc::absolutize_url($data, $base);
         }
         if ($type & (SIMPLEPIE_CONSTRUCT_TEXT | SIMPLEPIE_CONSTRUCT_IRI)) {
             $data = htmlspecialchars($data, ENT_COMPAT, 'UTF-8');
         }
         if ($this->output_encoding !== 'UTF-8') {
             $data = SimplePie_Misc::change_encoding($data, 'UTF-8', $this->output_encoding);
         }
     }
     return $data;
 }

/**
* fooStack lets plugins each extend their own CI libraries.
* in order to be able to do that we have to find out what files are to be included
* and what objects have to be intermediary
*/
function find_load_order($class)
{
    //user prefix
    $prefix = config_item('subclass_prefix');
    //foostack config var
    $fs = foo_config();
    //foostack end user class prefix - foostack classes can be exended by the user
    $fooprefix = $fs['prefix'];
    //main cases:
    //base classes - fooextension classes - fooadditional classes - user classes - user extension classes
    // load base class (fooconfig decideds if we extend it)
    // load non-base class, either fooclass
    $is_fooclass = FALSE;
    //is it in a subfolder?
    $folders = explode('/', $class);
    if (count($folders) > 1) {
        $class = array_pop($folders);
        $folders = join('/', $folders) . '/';
    } else {
        $folders = '';
    }
    //echo "folder:".print_r($folders,1);
    //echo "class:".print_r($class,1)." *\n";
    // Does the class exist?  If so, we're done...
    if (isset($objects[$class])) {
        return $objects[$class];
    }
    // user extension class?
    if (file_exists(APPPATH . 'libraries/' . $folders . $prefix . $class . EXT)) {
        // require Base Class
        require BASEPATH . 'libraries/' . $class . EXT;
        // extend with fooStack class
        if (file_exists(FSPATH . $fooprefix . $class . EXT)) {
            require FSPATH . $fooprefix . $class . EXT;
            $is_fooclass = TRUE;
        }
        // load user class
        require APPPATH . 'libraries/' . $folders . $prefix . $class . EXT;
        $is_subclass = TRUE;
    } else {
        // independent user class?
        if (file_exists(APPPATH . 'libraries/' . $folders . $class . EXT)) {
            //load it
            require APPPATH . 'libraries/' . $folders . $class . EXT;
            $is_subclass = FALSE;
            $is_fooclass = FALSE;
        } else {
            // so it must be a base class / or foostack class
            require BASEPATH . 'libraries/' . $class . EXT;
            if (file_exists(FSPATH . $fooprefix . $class . EXT)) {
                require FSPATH . $fooprefix . $class . EXT;
                $is_fooclass = TRUE;
            }
            $is_subclass = FALSE;
        }
    }
    if ($instantiate == FALSE) {
        $objects[$class] = TRUE;
        return $objects[$class];
    }
    if ($is_subclass == TRUE) {
        $name = $prefix . $class;
        echo "Subclass " . $name . " loading..";
        $objects[$class] =& instantiate_class(new $name());
        return $objects[$class];
    }
    $prefix = $is_fooclass ? $fooprefix : 'CI_';
    $name = $class != 'Controller' ? $prefix . $class : $class;
    //echo "Class ". $name. " loading..";
    $objects[$class] =& instantiate_class(new $name());
    return $objects[$class];
}