org.netfrag.glib/DesignPattern/RemoteProxy.php

<?php
/**
 * This file contains the DesignPattern::RemoteProxy class
 *
 * @author Andreas Motl <andreas.motl@ilo.de>
 * @package org.netfrag.glib
 * @name DesignPattern::RemoteProxy
 *
 *
 */


/**
 * <b>Cvs-Log:</b>
 *
 * <pre>
 * -------------------------------------------------------------------------
 *    $Id: RemoteProxy.php,v 1.16 2003/07/02 13:51:38 jonen Exp $
 * -------------------------------------------------------------------------
 *    $Log: RemoteProxy.php,v $
 *    Revision 1.16  2003/07/02 13:51:38  jonen
 *    removed debug dumper
 *
 *    Revision 1.15  2003/04/11 01:32:21  joko
 *    renamed logging function
 *
 *    Revision 1.14  2003/04/09 02:06:45  joko
 *    errormessage now shown preformatted
 *
 *    Revision 1.13  2003/04/04 17:38:03  joko
 *    modifications regarding error-/exception-handling and -tracing
 *
 *    Revision 1.12  2003/03/29 08:01:21  joko
 *    modified ErrorBoxing
 *
 *    Revision 1.11  2003/03/28 06:44:51  joko
 *    VERBOSE mode
 *
 *    Revision 1.10  2003/03/28 03:05:54  joko
 *    more fancy debugging-output
 *
 *    Revision 1.9  2003/03/10 23:05:25  joko
 *    + fixed metadata for phpDocumentor
 *
 *    Revision 1.8  2003/03/10 22:31:56  joko
 *    + fixed metadata for phpDocumentor
 *
 *    Revision 1.7  2003/03/09 15:51:44  joko
 *    + additional metadata for Autodia
 *
 *    Revision 1.6  2003/03/05 17:28:43  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.5  2003/03/05 17:02:22  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.4  2003/03/05 16:32:19  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.3  2003/03/05 16:10:17  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.2  2003/03/05 12:14:02  joko
 *    renamed method
 *    constructor argument expansion
 *
 *    Revision 1.1  2003/03/03 22:06:46  joko
 *    refactored from Data::Driver::Proxy
 *
 *    Revision 1.3  2003/03/01 04:56:38  joko
 *    new comment style for large blocks - stolen from phpHtmlLib
 *    commit-log encapsulated into such a block
 *    introduced some documentation
 *    refactored todo (now also inside a stylish block)
 *
 *    Revision 1.2  2003/02/13 21:48:09  joko
 *    + caching mechanisms more configurable now
 *
 *    Revision 1.1  2003/02/09 17:23:21  joko
 *    + refactored from flib/Application/RPC/ProxyObject.php
 *
 *    Revision 1.7  2003/02/03 03:31:38  jonen
 *    - moved '$encoder->toISO()' to 'Remote.php'
 *
 *    Revision 1.6  2002/12/22 13:26:20  jonen
 *    + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
 *
 *    Revision 1.5  2002/12/18 22:36:49  jonen
 *    + added support to get remote objects via backend via 'guid'
 *    + renamed '_loadBackend' to '_loadRemote'
 *    + constructor now accepts additional options:
 *      + remote: try to get object via '_loadRemote' ...
 *      + oid: use the given identifier as an 'oid' when doing '_loadRemote'
 *      + guid: use the given identifier as a 'guid' when doing '_loadRemote'
 *
 *    Revision 1.4  2002/12/12 02:46:31  joko
 *    + state (session) gets flushed when data was successfully loaded from remote side
 *    + fixed _loadBackend
 *    + fixed flushState
 *
 *    Revision 1.3  2002/12/06 04:12:54  joko
 *    + replaced 'xyzCache' through 'xyzProxy'
 *    + function store(...)
 *
 *    Revision 1.2  2002/12/05 21:44:09  joko
 *    + debugging
 *
 *    Revision 1.1  2002/12/01 17:23:58  joko
 *    + initial check-in
 *
 *    Revision 1.11  2002/11/12 06:05:58  cvsjoko
 *    + renamed class: Text_Encode -> TextEncode
 *
 *    Revision 1.10  2002/10/29 19:15:33  cvsjoko
 *    - moved utf8/iso-conversion to lib/utils/Text_Encode.php
 *
 *    Revision 1.9  2002/10/26 12:32:36  cvsjoko
 *    - removed debugging via "print"
 *    + added generic logging via PEAR::Log
 *
 *    Revision 1.8  2002/10/22 09:51:38  cvsmax
 *    + moved semi-method 'createBackend' to method $site->user->create at User.class.php
 *
 *    Revision 1.7  2002/10/21 18:27:09  cvsjoko
 *    - manually disabled any form of caching
 *
 *    Revision 1.6  2002/10/17 03:48:47  cvsmax
 *    + new
 *       + function _createBackend      create new Backend
 *       + function _create             api-create
 *
 *    Revision 1.5  2002/10/16 03:37:54  cvsjoko
 *    + bugfix: wrong comparison in restriction to save to array
 *
 *    Revision 1.4  2002/10/10 03:04:23  cvsjoko
 *    + no debug-output
 *
 *    Revision 1.3  2002/10/10 03:03:27  cvsjoko
 *    + bugfix: save object to cache only if payload from backend isn't empty
 *
 *    Revision 1.2  2002/10/10 02:40:06  cvsjoko
 *    + new level of data-caching (session and persistant)
 *        + function _loadState loads data from session
 *        + function _saveState saves data to session
 *        + function save               api-save (session & backend)
 *        + function _commit    saves data to backend
 *    + handy utils
 *        + function _setAttributes
 *        + function flushState
 *
 *    Revision 1.1  2002/10/09 00:51:39  cvsjoko
 *    + new
 * -------------------------------------------------------------------------
 * </pre>
 *
 */


/**
 * Load required modules:
 *
 */
loadModule('DesignPattern::Proxy');


/**
 * DesignPattern::RemoteProxy  --  Multiple stage data fetching and caching
 *
 *
 * This class (DesignPattern::RemoteProxy) provides an abstract framework 
 * for loading/saving arbitrary data from/to data storages interfaced 
 * by storage *proxy*-drivers.
 * Don't mix these up with the concrete storage *handle*-drivers 
 * doing the lowlevel stuff (opening files, talking sql, etc.).
 * These proxy-drivers are "just" wrappers around them 
 * providing a more highlevel, consistent API making
 * it easier for Data::Driver::Proxy to do its main work:
 *
 * quote from: http://home.earthlink.net/~huston2/dp/proxy.html
 * "A remote proxy provides a local representative for an 
 * object that resides in a different address space. This is 
 * what the "stub" code in RPC and CORBA provides."
 *
 *
 * Multiple stage data fetching and caching:
 *
 * <pre>
 *
 * DATA, ...
 *    ... also refered to as data, should be handled as 
 *    something called data.
 *
 * STAGES
 *    x native php4 session: serialized payload
 *    x single rdbms table: serialized payload
 *       x ... via custom database wrapper
 *          x included php-file, included php-library
 *          o object, component, package, callbacks
 *       x ... via php PEAR DB abstraction objects
 *    x remote objects (items): flat attribute hash
 *       o use Data::Object::Identity
 *       o via Data::Driver::Proxy::RPC or others
 *       o Data::Object::Encoder: encodes/decodes values
 *       o Data::Object::Interpolator: interpolates/resolves references
 * 
 * WORK
 *    x move data transparently around between these stages
 *
 * TOOLS
 *
 * x Overview - Packages, Handlers and Stages:
 *     This is weird.  ;-)
 *     - A Package can be instantiated by its namespaced classname
 *       e.g.: "mkObject('My::Package');"
 *     - A Package can be a Handler for Data::Driver::Proxy
 *     - A Handler implements exactly one Stage
 *     - Data::Driver::Proxy itself embeds these Stages:
 *        x php4-session
 *        x rdbms-table
 *     - An example Handler is Data::Driver::RPC::Remote
 *
 * x Handlers:
 *    x Data::Driver::RPC::Remote
 *        Interacts with a RPC::XML server (todo: talk SOAP!) 
 *        using PEAR::XML::RPC.
 *        It can cache data for "disconnected mode" using the
 *    o Data::Driver::phpHtmlLib
 *    o Data::Driver::PEAR::DB
 *    x Data::Driver::PEAR::Tree (via Data::Lift)
 *
 * </pre>
 *
 *
 * An attempt to implement some software design patterns
 * --- RemoteProxyPattern
 *
 * @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm
 * @link http://home.earthlink.net/~huston2/dp/proxy.html
 * @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject
 * @link http://c2.com/cgi-bin/wiki?ProxyPattern
 * @link http://c2.com/cgi-bin/wiki?LazyProxies
 *
 * @author Andreas Motl <andreas.motl@ilo.de>
 * @link http://www.netfrag.org/~joko/
 *
 * @copyright (c) 2003 - All Rights reserved.
 * @license GNU LGPL (GNU Lesser General Public License)
 * @link http://www.gnu.org/licenses/lgpl.txt
 *
 * @package org.netfrag.glib
 * @subpackage DesignPattern
 * @name DesignPattern::RemoteProxy
 *
 *
 * @todo extend options to en-/disable caching via a) session and/or b) database
 *           make feature available via runtime setter-method to these options
 * @todo PEAR::Cache for caching purposes!!!
 * @todo refactor database access: use PEAR for this! no more 'connectdb' here!!!
 * @todo make database connection more flexible to make possible
 *           to have different (probably named) proxy databases (besides a "main database")
 * @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper?
 * @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject)
 * @todo rename this to "DesignPattern::LazyRemoteProxy"???
 *
 */
class DesignPattern_RemoteProxy extends DesignPattern_Proxy {

  var $objectId;
  // purpose ...
  var $meta;
  var $payload;
  var $attributes;
  var $backend;

  function DesignPattern_RemoteProxy($objectId = "", $options = array() ) {
    php::log(get_class($this) . "->new()", PEAR_LOG_INFO);
    global $proxy;

    // 2003-03-05 - modified constructor
    // expand objectId
    if (is_array($objectId)) {
      $options = $objectId[1];
      $objectId = $objectId[0];
    }

    // trace
      //print Dumper($objectId, $options);

    // initialization/startup
      $this->_init_meta_options($objectId, $options);
      $this->_init_caching();
      $this->_init_load();

    //print Dumper($this);

  }

  function _init_meta_options( $objectId="", $options = array() ) {
    $this->meta = $options;

    if ($objectId) {
      $this->objectId = $objectId;
      
      // set default load mechanism
      if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) || ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) {
        $this->meta[oid] = 1;
      }
      
    }
  }

  function _init_caching() {
    
    if ($this->meta[cache][session]) {
      session_register_safe("proxy");
    }  

    /**
     * <!-- Autodia -->
     * can do: (this is metadata supplied for Autodia, don't delete!)
     *  $this->backend = new DataSource_Proxy_XMLRPC()
     *
     */

    if ($this->meta[remote]) {
      //$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]);
      $this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]);
    }
  }

  function _init_load() {
    if ($this->objectId) {
      $this->load();
      //$this->_saveProxy();
    }
  }


  function load() {
    php::log(get_class($this) . "->load()", PEAR_LOG_INFO);
    if (!$this->_loadState()) {
      if (!$this->_loadProxy()) {

        // just load object from remote side if its flagged to be a remote one ...
        if ($this->meta[remote]) {
          $this->_loadRemote();
        }

      }
    }
  }  

  function save($data, $type) {
    $this->_setAttributes($data);
    $this->_saveState();
    if ($type == 'commit') {
      $this->_commit();
    }
    if ($type == 'create') {
      $this->_create();
    }
  }  

  function flush() {
    $this->flushState();
    $this->flushProxy();
  }      

  function _commit() {
    $this->_saveBackend($this->attributes);
    $this->flushState();
    $this->flushProxy();
  }  


  // TODO: make this work
  /*
  function _create() {
    $this->_createBackend($this->attributes);
    $this->flushState();
    $this->flushProxy();
  }  
  */

  function getResult() {
    if (!$this->meta[decoded]) {
      $this->_decode();
      $this->_saveState();
    }
    return $this->attributes;
  }

  function _setAttributes($data) {
    $this->attributes = $data;
  }

  function getAttributes() {
    return $this->attributes;
  }

  function flushProxy() {
        connectdb();
    $sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'";
    send_sql($sql);
  }
  
  function flushState() {
    global $proxy;
    unset($proxy[$this->objectId]);
    $this->meta[decoded] = 0;
  }

  function _loadState() {
    global $proxy;

    // trace
      //print Dumper($this);

    // debug
      php::log(get_class($this) . "->_loadState()");
      
    if ($this->attributes = $proxy[$this->objectId]) {
      //print "_loadState:" . dumpVar($this->attributes);
      $this->meta[decoded] = 1;
      // TODO: make a parameter from this (0 deactivates session-layer)
      return 0;
    }
  }

  function _saveState() {
    global $proxy;
    php::log(get_class($this) . "->_saveState()");
    $proxy[$this->objectId] = $this->attributes;
    //print "_saveState: " . dumpVar($this->attributes);
    // TODO: throw exception-message back to user if operation fails
  }

  function _loadProxy() {
    
    // FIXME!
    if (!$this->meta[cache][db]) { return; }
    
    // trace & debug
      //print Dumper($this);
      php::log(get_class($this) . "->_loadProxy()");
      
    connectdb();
    $sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
    if ($res = send_sql($sql)) {
      $row = mysql_fetch_array($res, MYSQL_ASSOC);
      if ($row) {
        $this->payload = $row[payload];
        // TODO: make a parameter from this (0 deactivates mysqldb-layer)
        return 0;
      }
    }
  }
  
  // TODO: use PEAR here
  function _saveProxy() {

    // FIXME!
    if (!$this->meta[cache][db]) { return; }

    php::log(get_class($this) . "->_saveProxy()");
        connectdb();
        if ($this->payload) {
      //$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
      $sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
      if (!send_sql($sql)) {
        $sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
        send_sql($sql);
      }
    }
  }
  
  function _loadRemote() {
    php::log(get_class($this) . "->_loadRemote()");
    
    // trace
      //print Dumper($this->meta);
        
    // TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
    
    // 1. check backend-handle
    if (!$this->backend) {
      php::log(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
      return;
    }
    
    // determine backend action by metadata
      // check for guid or oid
      if ($this->meta[guid]) {
        if (!$this->objectId) {
          php::log(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
          return;
        }
        if (!$this->meta[classname]) {
          php::log(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
          return;
        }
        php::log(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
        $args = array( guid => $this->objectId, classname => $this->meta[classname] );
        $result = $this->backend->send('getObjectByGuid', $args );

      } elseif ($this->meta[oid]) {
        if (!$this->objectId) {
          php::log(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
          return;
        }
        php::log(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
        $result = $this->backend->send('getObject', $this->objectId);

      } elseif ($this->meta[key]) {
        if (!$this->meta[command]) {
          php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
          return;
        }
        /*
        if (!$this->meta[query]) {
          php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
          return;
        }
        */
        //php::log(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
        //print Dumper(array($this->meta[command], $this->meta[query]));
        $result = $this->backend->send($this->meta[command], $this->meta[query]);
        
      }

    //print "result: " . dumpVar($result) . "<br>";

    $status = $this->backend->status();
    //print Dumper($status);
    
    $good = is_array($result) && sizeof($result) && $status[connected];

    if ($good) {
      
      // FIXME: this is dangerous!
      /*
      if ($_GET[debug]) {
        print Dumper($result);
      }
      */
      
      $this->payload = serialize($result);
      // ----- move this to _encode some times
      
      $this->_saveProxy();
      //print "oid: $this->objectId<br>";
      $this->flushState();
    
    } else {
      
      if (constants::get('APP_MODE_DEBUG')) {
        $this->draw_error_box($status);
      } else {
        php::maintenance('rpc', array( status => $status ) );
      }
    
    }
    
  }

function draw_error_box($status) {
  $style = html_style("text/css", '.boxlabel_yellow { color: yellow; font-weight:bold; }');
  $statusbox = html_div();
  $statusbox->set_style('background: red; border: 2px black groove; width:640px; padding:10px; margin:40px;');
  $statusbox->add( html_span('boxlabel_yellow', "Method:"), get_class($this) . "->_loadRemote", html_br() );
  $statusbox->add( html_span('boxlabel_yellow', "Connected:"), $status[connected], html_br() );
  $statusbox->add( html_span('boxlabel_yellow', "RPCSESSID:"), $status[RPCSESSID], html_br() );
  foreach ($status[errors] as $error) {
    $msg = html_pre($error[message]);
    $statusbox->add( html_span('boxlabel_yellow', "Error($error[code]):"), $msg );
  }
  
  $message = "Error while talking to remote side. Please check wire, socket or api.";
  php::log($message, PEAR_LOG_CRIT);
  $statusbox->add( html_span('boxlabel_yellow', "Critical:"), $message, html_br() );

  // V1
  /*
  if (constants::get('VERBOSE') || constants::get('ERRORS_ONLY')) {
    print $style->render();
    print $statusbox->render();
  } else {
    foreach ($status[errors] as $error) {
      print Dumper($error);
    }
  }
  */

  // V2
  trace( container($style, $statusbox) );

}  


  function _saveBackend($result) {
    php::log(get_class($this) . "->_saveBackend()");

    //$encoder = new TextEncode($result);
    //$encoder->toUTF8();

    // check for guid or oid
    if($this->meta[guid]) {
      $args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result );
      $response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) );
    }
    if($this->meta[oid]) {
      $response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1)  );
    }
  }

  function _decode() {
    // fill attributes-hashtable from message-hashtable
    if (!$this->payload) { return; }
    //if ($this->attributes = $backend->decodeData($this->payload)) {
    if ($this->attributes = unserialize($this->payload)) {
      $this->meta[decoded] = 1;
    }
  }
  
  function store($struct) {
    $this->payload = serialize($struct);
    $this->_saveProxy();
  }

}

?>
1	joko	1.1	<?php
2	joko	1.3	/**
3			* This file contains the DesignPattern::RemoteProxy class
4			*
5			* @author Andreas Motl <andreas.motl@ilo.de>
6			* @package org.netfrag.glib
7			* @name DesignPattern::RemoteProxy
8			*
9	joko	1.4	*
10	joko	1.9	*/
11
12
13			/**
14	joko	1.4	* <b>Cvs-Log:</b>
15			*
16			* <pre>
17	joko	1.1	* -------------------------------------------------------------------------
18	jonen	1.17	* $Id: RemoteProxy.php,v 1.16 2003/07/02 13:51:38 jonen Exp $
19	joko	1.1	* -------------------------------------------------------------------------
20	joko	1.2	* $Log: RemoteProxy.php,v $
21	jonen	1.17	* Revision 1.16 2003/07/02 13:51:38 jonen
22			* removed debug dumper
23			*
24	jonen	1.16	* Revision 1.15 2003/04/11 01:32:21 joko
25			* renamed logging function
26			*
27	joko	1.15	* Revision 1.14 2003/04/09 02:06:45 joko
28			* errormessage now shown preformatted
29			*
30	joko	1.14	* Revision 1.13 2003/04/04 17:38:03 joko
31			* modifications regarding error-/exception-handling and -tracing
32			*
33	joko	1.13	* Revision 1.12 2003/03/29 08:01:21 joko
34			* modified ErrorBoxing
35			*
36	joko	1.12	* Revision 1.11 2003/03/28 06:44:51 joko
37			* VERBOSE mode
38			*
39	joko	1.11	* Revision 1.10 2003/03/28 03:05:54 joko
40			* more fancy debugging-output
41			*
42	joko	1.10	* Revision 1.9 2003/03/10 23:05:25 joko
43			* + fixed metadata for phpDocumentor
44			*
45	joko	1.9	* Revision 1.8 2003/03/10 22:31:56 joko
46			* + fixed metadata for phpDocumentor
47			*
48	joko	1.8	* Revision 1.7 2003/03/09 15:51:44 joko
49			* + additional metadata for Autodia
50			*
51	joko	1.7	* Revision 1.6 2003/03/05 17:28:43 joko
52			* updated docu (phpDocumentor testing....)
53			*
54	joko	1.6	* Revision 1.5 2003/03/05 17:02:22 joko
55			* updated docu (phpDocumentor testing....)
56			*
57	joko	1.5	* Revision 1.4 2003/03/05 16:32:19 joko
58			* updated docu (phpDocumentor testing....)
59			*
60	joko	1.4	* Revision 1.3 2003/03/05 16:10:17 joko
61			* updated docu (phpDocumentor testing....)
62			*
63	joko	1.3	* Revision 1.2 2003/03/05 12:14:02 joko
64			* renamed method
65			* constructor argument expansion
66			*
67	joko	1.2	* Revision 1.1 2003/03/03 22:06:46 joko
68			* refactored from Data::Driver::Proxy
69			*
70	joko	1.1	* Revision 1.3 2003/03/01 04:56:38 joko
71			* new comment style for large blocks - stolen from phpHtmlLib
72			* commit-log encapsulated into such a block
73			* introduced some documentation
74			* refactored todo (now also inside a stylish block)
75			*
76			* Revision 1.2 2003/02/13 21:48:09 joko
77			* + caching mechanisms more configurable now
78			*
79			* Revision 1.1 2003/02/09 17:23:21 joko
80			* + refactored from flib/Application/RPC/ProxyObject.php
81			*
82			* Revision 1.7 2003/02/03 03:31:38 jonen
83			* - moved '$encoder->toISO()' to 'Remote.php'
84			*
85			* Revision 1.6 2002/12/22 13:26:20 jonen
86			* + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
87			*
88			* Revision 1.5 2002/12/18 22:36:49 jonen
89			* + added support to get remote objects via backend via 'guid'
90			* + renamed '_loadBackend' to '_loadRemote'
91			* + constructor now accepts additional options:
92			* + remote: try to get object via '_loadRemote' ...
93			* + oid: use the given identifier as an 'oid' when doing '_loadRemote'
94			* + guid: use the given identifier as a 'guid' when doing '_loadRemote'
95			*
96			* Revision 1.4 2002/12/12 02:46:31 joko
97			* + state (session) gets flushed when data was successfully loaded from remote side
98			* + fixed _loadBackend
99			* + fixed flushState
100			*
101			* Revision 1.3 2002/12/06 04:12:54 joko
102			* + replaced 'xyzCache' through 'xyzProxy'
103			* + function store(...)
104			*
105			* Revision 1.2 2002/12/05 21:44:09 joko
106			* + debugging
107			*
108			* Revision 1.1 2002/12/01 17:23:58 joko
109			* + initial check-in
110			*
111			* Revision 1.11 2002/11/12 06:05:58 cvsjoko
112			* + renamed class: Text_Encode -> TextEncode
113			*
114			* Revision 1.10 2002/10/29 19:15:33 cvsjoko
115			* - moved utf8/iso-conversion to lib/utils/Text_Encode.php
116			*
117			* Revision 1.9 2002/10/26 12:32:36 cvsjoko
118			* - removed debugging via "print"
119			* + added generic logging via PEAR::Log
120			*
121			* Revision 1.8 2002/10/22 09:51:38 cvsmax
122			* + moved semi-method 'createBackend' to method $site->user->create at User.class.php
123			*
124			* Revision 1.7 2002/10/21 18:27:09 cvsjoko
125			* - manually disabled any form of caching
126			*
127			* Revision 1.6 2002/10/17 03:48:47 cvsmax
128			* + new
129			* + function _createBackend create new Backend
130			* + function _create api-create
131			*
132			* Revision 1.5 2002/10/16 03:37:54 cvsjoko
133			* + bugfix: wrong comparison in restriction to save to array
134			*
135			* Revision 1.4 2002/10/10 03:04:23 cvsjoko
136			* + no debug-output
137			*
138			* Revision 1.3 2002/10/10 03:03:27 cvsjoko
139			* + bugfix: save object to cache only if payload from backend isn't empty
140			*
141			* Revision 1.2 2002/10/10 02:40:06 cvsjoko
142			* + new level of data-caching (session and persistant)
143			* + function _loadState loads data from session
144			* + function _saveState saves data to session
145			* + function save api-save (session & backend)
146			* + function _commit saves data to backend
147			* + handy utils
148			* + function _setAttributes
149			* + function flushState
150			*
151			* Revision 1.1 2002/10/09 00:51:39 cvsjoko
152			* + new
153			* -------------------------------------------------------------------------
154	joko	1.4	* </pre>
155			*
156	joko	1.1	*/
157
158	joko	1.4
159
160
161			/**
162			* Load required modules:
163			*
164			*/
165			loadModule('DesignPattern::Proxy');
166
167
168	joko	1.1	/**
169	joko	1.7	* DesignPattern::RemoteProxy -- Multiple stage data fetching and caching
170	joko	1.1	*
171			*
172	joko	1.7	* This class (DesignPattern::RemoteProxy) provides an abstract framework
173	joko	1.1	* for loading/saving arbitrary data from/to data storages interfaced
174			* by storage proxy-drivers.
175			* Don't mix these up with the concrete storage handle-drivers
176			* doing the lowlevel stuff (opening files, talking sql, etc.).
177			* These proxy-drivers are "just" wrappers around them
178			* providing a more highlevel, consistent API making
179			* it easier for Data::Driver::Proxy to do its main work:
180			*
181	joko	1.7	* quote from: http://home.earthlink.net/~huston2/dp/proxy.html
182			* "A remote proxy provides a local representative for an
183			* object that resides in a different address space. This is
184			* what the "stub" code in RPC and CORBA provides."
185			*
186			*
187	joko	1.1	* Multiple stage data fetching and caching:
188			*
189	joko	1.4	* <pre>
190			*
191	joko	1.1	* DATA, ...
192			* ... also refered to as data, should be handled as
193			* something called data.
194			*
195			* STAGES
196			* x native php4 session: serialized payload
197			* x single rdbms table: serialized payload
198			* x ... via custom database wrapper
199			* x included php-file, included php-library
200			* o object, component, package, callbacks
201			* x ... via php PEAR DB abstraction objects
202			* x remote objects (items): flat attribute hash
203			* o use Data::Object::Identity
204			* o via Data::Driver::Proxy::RPC or others
205			* o Data::Object::Encoder: encodes/decodes values
206			* o Data::Object::Interpolator: interpolates/resolves references
207			*
208			* WORK
209			* x move data transparently around between these stages
210			*
211			* TOOLS
212			*
213			* x Overview - Packages, Handlers and Stages:
214			* This is weird. ;-)
215			* - A Package can be instantiated by its namespaced classname
216			* e.g.: "mkObject('My::Package');"
217			* - A Package can be a Handler for Data::Driver::Proxy
218			* - A Handler implements exactly one Stage
219			* - Data::Driver::Proxy itself embeds these Stages:
220			* x php4-session
221			* x rdbms-table
222			* - An example Handler is Data::Driver::RPC::Remote
223			*
224			* x Handlers:
225			* x Data::Driver::RPC::Remote
226			* Interacts with a RPC::XML server (todo: talk SOAP!)
227			* using PEAR::XML::RPC.
228			* It can cache data for "disconnected mode" using the
229			* o Data::Driver::phpHtmlLib
230			* o Data::Driver::PEAR::DB
231			* x Data::Driver::PEAR::Tree (via Data::Lift)
232			*
233	joko	1.4	* </pre>
234			*
235			*
236			* An attempt to implement some software design patterns
237	joko	1.3	* --- RemoteProxyPattern
238			*
239	joko	1.7	* @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm
240			* @link http://home.earthlink.net/~huston2/dp/proxy.html
241			* @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject
242	joko	1.3	* @link http://c2.com/cgi-bin/wiki?ProxyPattern
243	joko	1.7	* @link http://c2.com/cgi-bin/wiki?LazyProxies
244	joko	1.3	*
245			* @author Andreas Motl <andreas.motl@ilo.de>
246			* @link http://www.netfrag.org/~joko/
247			*
248			* @copyright (c) 2003 - All Rights reserved.
249			* @license GNU LGPL (GNU Lesser General Public License)
250			* @link http://www.gnu.org/licenses/lgpl.txt
251			*
252			* @package org.netfrag.glib
253	joko	1.6	* @subpackage DesignPattern
254	joko	1.3	* @name DesignPattern::RemoteProxy
255			*
256	joko	1.4	*
257	joko	1.7	* @todo extend options to en-/disable caching via a) session and/or b) database
258			* make feature available via runtime setter-method to these options
259			* @todo PEAR::Cache for caching purposes!!!
260			* @todo refactor database access: use PEAR for this! no more 'connectdb' here!!!
261			* @todo make database connection more flexible to make possible
262			* to have different (probably named) proxy databases (besides a "main database")
263			* @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper?
264			* @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject)
265			* @todo rename this to "DesignPattern::LazyRemoteProxy"???
266	joko	1.1	*
267			*/
268			class DesignPattern_RemoteProxy extends DesignPattern_Proxy {
269
270			var $objectId;
271			// purpose ...
272			var $meta;
273			var $payload;
274			var $attributes;
275			var $backend;
276
277			function DesignPattern_RemoteProxy($objectId = "", $options = array() ) {
278	joko	1.15	php::log(get_class($this) . "->new()", PEAR_LOG_INFO);
279	joko	1.1	global $proxy;
280
281	joko	1.2	// 2003-03-05 - modified constructor
282			// expand objectId
283			if (is_array($objectId)) {
284			$options = $objectId[1];
285			$objectId = $objectId[0];
286			}
287
288	joko	1.1	// trace
289			//print Dumper($objectId, $options);
290
291			// initialization/startup
292			$this->_init_meta_options($objectId, $options);
293			$this->_init_caching();
294			$this->_init_load();
295
296	joko	1.2	//print Dumper($this);
297
298	joko	1.1	}
299
300			function _init_meta_options( $objectId="", $options = array() ) {
301			$this->meta = $options;
302
303			if ($objectId) {
304			$this->objectId = $objectId;
305
306			// set default load mechanism
307			if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) \|\| ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) {
308			$this->meta[oid] = 1;
309			}
310
311			}
312			}
313
314			function _init_caching() {
315
316			if ($this->meta[cache][session]) {
317			session_register_safe("proxy");
318			}
319	joko	1.7
320			/**
321			* <!-- Autodia -->
322			* can do: (this is metadata supplied for Autodia, don't delete!)
323			* $this->backend = new DataSource_Proxy_XMLRPC()
324			*
325			*/
326	joko	1.1
327			if ($this->meta[remote]) {
328			//$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]);
329	joko	1.2	$this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]);
330	joko	1.1	}
331			}
332
333			function _init_load() {
334			if ($this->objectId) {
335			$this->load();
336			//$this->_saveProxy();
337			}
338			}
339
340
341			function load() {
342	joko	1.15	php::log(get_class($this) . "->load()", PEAR_LOG_INFO);
343	joko	1.1	if (!$this->_loadState()) {
344			if (!$this->_loadProxy()) {
345
346			// just load object from remote side if its flagged to be a remote one ...
347			if ($this->meta[remote]) {
348			$this->_loadRemote();
349			}
350
351			}
352			}
353			}
354
355			function save($data, $type) {
356			$this->_setAttributes($data);
357			$this->_saveState();
358			if ($type == 'commit') {
359			$this->_commit();
360			}
361			if ($type == 'create') {
362			$this->_create();
363			}
364			}
365
366			function flush() {
367			$this->flushState();
368			$this->flushProxy();
369			}
370
371			function _commit() {
372			$this->_saveBackend($this->attributes);
373			$this->flushState();
374			$this->flushProxy();
375			}
376
377
378			// TODO: make this work
379			/*
380			function _create() {
381			$this->_createBackend($this->attributes);
382			$this->flushState();
383			$this->flushProxy();
384			}
385			*/
386
387	joko	1.2	function getResult() {
388	joko	1.1	if (!$this->meta[decoded]) {
389			$this->_decode();
390			$this->_saveState();
391			}
392			return $this->attributes;
393			}
394
395			function _setAttributes($data) {
396			$this->attributes = $data;
397	jonen	1.17	}
398
399			function getAttributes() {
400			return $this->attributes;
401	joko	1.1	}
402
403			function flushProxy() {
404			connectdb();
405			$sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'";
406			send_sql($sql);
407			}
408
409			function flushState() {
410			global $proxy;
411			unset($proxy[$this->objectId]);
412			$this->meta[decoded] = 0;
413			}
414
415			function _loadState() {
416			global $proxy;
417
418			// trace
419			//print Dumper($this);
420
421			// debug
422	joko	1.15	php::log(get_class($this) . "->_loadState()");
423	joko	1.1
424			if ($this->attributes = $proxy[$this->objectId]) {
425			//print "_loadState:" . dumpVar($this->attributes);
426			$this->meta[decoded] = 1;
427			// TODO: make a parameter from this (0 deactivates session-layer)
428			return 0;
429			}
430			}
431
432			function _saveState() {
433			global $proxy;
434	joko	1.15	php::log(get_class($this) . "->_saveState()");
435	joko	1.1	$proxy[$this->objectId] = $this->attributes;
436			//print "_saveState: " . dumpVar($this->attributes);
437			// TODO: throw exception-message back to user if operation fails
438			}
439
440			function _loadProxy() {
441
442			// FIXME!
443			if (!$this->meta[cache][db]) { return; }
444
445			// trace & debug
446			//print Dumper($this);
447	joko	1.15	php::log(get_class($this) . "->_loadProxy()");
448	joko	1.1
449			connectdb();
450			$sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
451			if ($res = send_sql($sql)) {
452			$row = mysql_fetch_array($res, MYSQL_ASSOC);
453			if ($row) {
454			$this->payload = $row[payload];
455			// TODO: make a parameter from this (0 deactivates mysqldb-layer)
456			return 0;
457			}
458			}
459			}
460
461			// TODO: use PEAR here
462			function _saveProxy() {
463
464			// FIXME!
465			if (!$this->meta[cache][db]) { return; }
466
467	joko	1.15	php::log(get_class($this) . "->_saveProxy()");
468	joko	1.1	connectdb();
469			if ($this->payload) {
470			//$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
471			$sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
472			if (!send_sql($sql)) {
473			$sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
474			send_sql($sql);
475			}
476			}
477			}
478
479			function _loadRemote() {
480	joko	1.15	php::log(get_class($this) . "->_loadRemote()");
481	joko	1.1
482			// trace
483			//print Dumper($this->meta);
484
485			// TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
486
487			// 1. check backend-handle
488			if (!$this->backend) {
489	joko	1.15	php::log(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
490	joko	1.1	return;
491			}
492
493			// determine backend action by metadata
494			// check for guid or oid
495			if ($this->meta[guid]) {
496			if (!$this->objectId) {
497	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
498	joko	1.1	return;
499			}
500			if (!$this->meta[classname]) {
501	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
502	joko	1.1	return;
503			}
504	joko	1.15	php::log(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
505	joko	1.1	$args = array( guid => $this->objectId, classname => $this->meta[classname] );
506			$result = $this->backend->send('getObjectByGuid', $args );
507
508			} elseif ($this->meta[oid]) {
509			if (!$this->objectId) {
510	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
511	joko	1.1	return;
512			}
513	joko	1.15	php::log(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
514	joko	1.1	$result = $this->backend->send('getObject', $this->objectId);
515
516			} elseif ($this->meta[key]) {
517			if (!$this->meta[command]) {
518	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
519	joko	1.1	return;
520			}
521			/*
522			if (!$this->meta[query]) {
523	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
524	joko	1.1	return;
525			}
526			*/
527	joko	1.15	//php::log(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
528	joko	1.10	//print Dumper(array($this->meta[command], $this->meta[query]));
529	joko	1.1	$result = $this->backend->send($this->meta[command], $this->meta[query]);
530
531			}
532
533	joko	1.10	//print "result: " . dumpVar($result) . "<br>";
534	joko	1.1
535	joko	1.13	$status = $this->backend->status();
536	joko	1.10	//print Dumper($status);
537
538	joko	1.13	$good = is_array($result) && sizeof($result) && $status[connected];
539	joko	1.10
540	joko	1.13	if ($good) {
541	joko	1.1
542			// FIXME: this is dangerous!
543	joko	1.13	/*
544	joko	1.1	if ($_GET[debug]) {
545			print Dumper($result);
546			}
547	joko	1.13	*/
548	joko	1.1
549			$this->payload = serialize($result);
550			// ----- move this to _encode some times
551
552			$this->_saveProxy();
553			//print "oid: $this->objectId<br>";
554			$this->flushState();
555	joko	1.10
556	joko	1.1	} else {
557	joko	1.13
558			if (constants::get('APP_MODE_DEBUG')) {
559			$this->draw_error_box($status);
560	joko	1.11	} else {
561	joko	1.13	php::maintenance('rpc', array( status => $status ) );
562	joko	1.11	}
563	joko	1.10
564	joko	1.1	}
565
566			}
567	joko	1.13
568			function draw_error_box($status) {
569			$style = html_style("text/css", '.boxlabel_yellow { color: yellow; font-weight:bold; }');
570			$statusbox = html_div();
571			$statusbox->set_style('background: red; border: 2px black groove; width:640px; padding:10px; margin:40px;');
572			$statusbox->add( html_span('boxlabel_yellow', "Method:"), get_class($this) . "->_loadRemote", html_br() );
573			$statusbox->add( html_span('boxlabel_yellow', "Connected:"), $status[connected], html_br() );
574			$statusbox->add( html_span('boxlabel_yellow', "RPCSESSID:"), $status[RPCSESSID], html_br() );
575			foreach ($status[errors] as $error) {
576	joko	1.14	$msg = html_pre($error[message]);
577			$statusbox->add( html_span('boxlabel_yellow', "Error($error[code]):"), $msg );
578	joko	1.13	}
579	joko	1.1
580	joko	1.13	$message = "Error while talking to remote side. Please check wire, socket or api.";
581	joko	1.15	php::log($message, PEAR_LOG_CRIT);
582	joko	1.13	$statusbox->add( html_span('boxlabel_yellow', "Critical:"), $message, html_br() );
583
584			// V1
585			/*
586			if (constants::get('VERBOSE') \|\| constants::get('ERRORS_ONLY')) {
587			print $style->render();
588			print $statusbox->render();
589			} else {
590			foreach ($status[errors] as $error) {
591			print Dumper($error);
592			}
593			}
594			*/
595
596			// V2
597			trace( container($style, $statusbox) );
598
599			}
600
601
602	joko	1.1	function _saveBackend($result) {
603	joko	1.15	php::log(get_class($this) . "->_saveBackend()");
604	joko	1.1
605			//$encoder = new TextEncode($result);
606			//$encoder->toUTF8();
607
608			// check for guid or oid
609			if($this->meta[guid]) {
610			$args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result );
611			$response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) );
612			}
613			if($this->meta[oid]) {
614			$response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1) );
615			}
616			}
617
618			function _decode() {
619			// fill attributes-hashtable from message-hashtable
620			if (!$this->payload) { return; }
621			//if ($this->attributes = $backend->decodeData($this->payload)) {
622			if ($this->attributes = unserialize($this->payload)) {
623			$this->meta[decoded] = 1;
624			}
625			}
626
627			function store($struct) {
628			$this->payload = serialize($struct);
629			$this->_saveProxy();
630			}
631
632			}
633
634	jonen	1.16	?>
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