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 1.17 2003/07/14 10:05:23 jonen Exp $
 * -------------------------------------------------------------------------
 *    $Log: RemoteProxy.php,v $
 *    Revision 1.17  2003/07/14 10:05:23  jonen
 *    bugfix: added *needed* function 'getAttributes'
 *
 *    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, array( utf8 => 1)  );

      } 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, array( utf8 => 1) );

      } 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], array( utf8 => 1) );
        
      }

    //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	1.18	* $Id: RemoteProxy.php,v 1.17 2003/07/14 10:05:23 jonen Exp $
19	joko	1.1	* -------------------------------------------------------------------------
20	joko	1.2	* $Log: RemoteProxy.php,v $
21	jonen	1.18	* Revision 1.17 2003/07/14 10:05:23 jonen
22			* bugfix: added needed function 'getAttributes'
23			*
24	jonen	1.17	* Revision 1.16 2003/07/02 13:51:38 jonen
25			* removed debug dumper
26			*
27	jonen	1.16	* Revision 1.15 2003/04/11 01:32:21 joko
28			* renamed logging function
29			*
30	joko	1.15	* Revision 1.14 2003/04/09 02:06:45 joko
31			* errormessage now shown preformatted
32			*
33	joko	1.14	* Revision 1.13 2003/04/04 17:38:03 joko
34			* modifications regarding error-/exception-handling and -tracing
35			*
36	joko	1.13	* Revision 1.12 2003/03/29 08:01:21 joko
37			* modified ErrorBoxing
38			*
39	joko	1.12	* Revision 1.11 2003/03/28 06:44:51 joko
40			* VERBOSE mode
41			*
42	joko	1.11	* Revision 1.10 2003/03/28 03:05:54 joko
43			* more fancy debugging-output
44			*
45	joko	1.10	* Revision 1.9 2003/03/10 23:05:25 joko
46			* + fixed metadata for phpDocumentor
47			*
48	joko	1.9	* Revision 1.8 2003/03/10 22:31:56 joko
49			* + fixed metadata for phpDocumentor
50			*
51	joko	1.8	* Revision 1.7 2003/03/09 15:51:44 joko
52			* + additional metadata for Autodia
53			*
54	joko	1.7	* Revision 1.6 2003/03/05 17:28:43 joko
55			* updated docu (phpDocumentor testing....)
56			*
57	joko	1.6	* Revision 1.5 2003/03/05 17:02:22 joko
58			* updated docu (phpDocumentor testing....)
59			*
60	joko	1.5	* Revision 1.4 2003/03/05 16:32:19 joko
61			* updated docu (phpDocumentor testing....)
62			*
63	joko	1.4	* Revision 1.3 2003/03/05 16:10:17 joko
64			* updated docu (phpDocumentor testing....)
65			*
66	joko	1.3	* Revision 1.2 2003/03/05 12:14:02 joko
67			* renamed method
68			* constructor argument expansion
69			*
70	joko	1.2	* Revision 1.1 2003/03/03 22:06:46 joko
71			* refactored from Data::Driver::Proxy
72			*
73	joko	1.1	* Revision 1.3 2003/03/01 04:56:38 joko
74			* new comment style for large blocks - stolen from phpHtmlLib
75			* commit-log encapsulated into such a block
76			* introduced some documentation
77			* refactored todo (now also inside a stylish block)
78			*
79			* Revision 1.2 2003/02/13 21:48:09 joko
80			* + caching mechanisms more configurable now
81			*
82			* Revision 1.1 2003/02/09 17:23:21 joko
83			* + refactored from flib/Application/RPC/ProxyObject.php
84			*
85			* Revision 1.7 2003/02/03 03:31:38 jonen
86			* - moved '$encoder->toISO()' to 'Remote.php'
87			*
88			* Revision 1.6 2002/12/22 13:26:20 jonen
89			* + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
90			*
91			* Revision 1.5 2002/12/18 22:36:49 jonen
92			* + added support to get remote objects via backend via 'guid'
93			* + renamed '_loadBackend' to '_loadRemote'
94			* + constructor now accepts additional options:
95			* + remote: try to get object via '_loadRemote' ...
96			* + oid: use the given identifier as an 'oid' when doing '_loadRemote'
97			* + guid: use the given identifier as a 'guid' when doing '_loadRemote'
98			*
99			* Revision 1.4 2002/12/12 02:46:31 joko
100			* + state (session) gets flushed when data was successfully loaded from remote side
101			* + fixed _loadBackend
102			* + fixed flushState
103			*
104			* Revision 1.3 2002/12/06 04:12:54 joko
105			* + replaced 'xyzCache' through 'xyzProxy'
106			* + function store(...)
107			*
108			* Revision 1.2 2002/12/05 21:44:09 joko
109			* + debugging
110			*
111			* Revision 1.1 2002/12/01 17:23:58 joko
112			* + initial check-in
113			*
114			* Revision 1.11 2002/11/12 06:05:58 cvsjoko
115			* + renamed class: Text_Encode -> TextEncode
116			*
117			* Revision 1.10 2002/10/29 19:15:33 cvsjoko
118			* - moved utf8/iso-conversion to lib/utils/Text_Encode.php
119			*
120			* Revision 1.9 2002/10/26 12:32:36 cvsjoko
121			* - removed debugging via "print"
122			* + added generic logging via PEAR::Log
123			*
124			* Revision 1.8 2002/10/22 09:51:38 cvsmax
125			* + moved semi-method 'createBackend' to method $site->user->create at User.class.php
126			*
127			* Revision 1.7 2002/10/21 18:27:09 cvsjoko
128			* - manually disabled any form of caching
129			*
130			* Revision 1.6 2002/10/17 03:48:47 cvsmax
131			* + new
132			* + function _createBackend create new Backend
133			* + function _create api-create
134			*
135			* Revision 1.5 2002/10/16 03:37:54 cvsjoko
136			* + bugfix: wrong comparison in restriction to save to array
137			*
138			* Revision 1.4 2002/10/10 03:04:23 cvsjoko
139			* + no debug-output
140			*
141			* Revision 1.3 2002/10/10 03:03:27 cvsjoko
142			* + bugfix: save object to cache only if payload from backend isn't empty
143			*
144			* Revision 1.2 2002/10/10 02:40:06 cvsjoko
145			* + new level of data-caching (session and persistant)
146			* + function _loadState loads data from session
147			* + function _saveState saves data to session
148			* + function save api-save (session & backend)
149			* + function _commit saves data to backend
150			* + handy utils
151			* + function _setAttributes
152			* + function flushState
153			*
154			* Revision 1.1 2002/10/09 00:51:39 cvsjoko
155			* + new
156			* -------------------------------------------------------------------------
157	joko	1.4	* </pre>
158			*
159	joko	1.1	*/
160
161	joko	1.4
162
163
164			/**
165			* Load required modules:
166			*
167			*/
168			loadModule('DesignPattern::Proxy');
169
170
171	joko	1.1	/**
172	joko	1.7	* DesignPattern::RemoteProxy -- Multiple stage data fetching and caching
173	joko	1.1	*
174			*
175	joko	1.7	* This class (DesignPattern::RemoteProxy) provides an abstract framework
176	joko	1.1	* for loading/saving arbitrary data from/to data storages interfaced
177			* by storage proxy-drivers.
178			* Don't mix these up with the concrete storage handle-drivers
179			* doing the lowlevel stuff (opening files, talking sql, etc.).
180			* These proxy-drivers are "just" wrappers around them
181			* providing a more highlevel, consistent API making
182			* it easier for Data::Driver::Proxy to do its main work:
183			*
184	joko	1.7	* quote from: http://home.earthlink.net/~huston2/dp/proxy.html
185			* "A remote proxy provides a local representative for an
186			* object that resides in a different address space. This is
187			* what the "stub" code in RPC and CORBA provides."
188			*
189			*
190	joko	1.1	* Multiple stage data fetching and caching:
191			*
192	joko	1.4	* <pre>
193			*
194	joko	1.1	* DATA, ...
195			* ... also refered to as data, should be handled as
196			* something called data.
197			*
198			* STAGES
199			* x native php4 session: serialized payload
200			* x single rdbms table: serialized payload
201			* x ... via custom database wrapper
202			* x included php-file, included php-library
203			* o object, component, package, callbacks
204			* x ... via php PEAR DB abstraction objects
205			* x remote objects (items): flat attribute hash
206			* o use Data::Object::Identity
207			* o via Data::Driver::Proxy::RPC or others
208			* o Data::Object::Encoder: encodes/decodes values
209			* o Data::Object::Interpolator: interpolates/resolves references
210			*
211			* WORK
212			* x move data transparently around between these stages
213			*
214			* TOOLS
215			*
216			* x Overview - Packages, Handlers and Stages:
217			* This is weird. ;-)
218			* - A Package can be instantiated by its namespaced classname
219			* e.g.: "mkObject('My::Package');"
220			* - A Package can be a Handler for Data::Driver::Proxy
221			* - A Handler implements exactly one Stage
222			* - Data::Driver::Proxy itself embeds these Stages:
223			* x php4-session
224			* x rdbms-table
225			* - An example Handler is Data::Driver::RPC::Remote
226			*
227			* x Handlers:
228			* x Data::Driver::RPC::Remote
229			* Interacts with a RPC::XML server (todo: talk SOAP!)
230			* using PEAR::XML::RPC.
231			* It can cache data for "disconnected mode" using the
232			* o Data::Driver::phpHtmlLib
233			* o Data::Driver::PEAR::DB
234			* x Data::Driver::PEAR::Tree (via Data::Lift)
235			*
236	joko	1.4	* </pre>
237			*
238			*
239			* An attempt to implement some software design patterns
240	joko	1.3	* --- RemoteProxyPattern
241			*
242	joko	1.7	* @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm
243			* @link http://home.earthlink.net/~huston2/dp/proxy.html
244			* @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject
245	joko	1.3	* @link http://c2.com/cgi-bin/wiki?ProxyPattern
246	joko	1.7	* @link http://c2.com/cgi-bin/wiki?LazyProxies
247	joko	1.3	*
248			* @author Andreas Motl <andreas.motl@ilo.de>
249			* @link http://www.netfrag.org/~joko/
250			*
251			* @copyright (c) 2003 - All Rights reserved.
252			* @license GNU LGPL (GNU Lesser General Public License)
253			* @link http://www.gnu.org/licenses/lgpl.txt
254			*
255			* @package org.netfrag.glib
256	joko	1.6	* @subpackage DesignPattern
257	joko	1.3	* @name DesignPattern::RemoteProxy
258			*
259	joko	1.4	*
260	joko	1.7	* @todo extend options to en-/disable caching via a) session and/or b) database
261			* make feature available via runtime setter-method to these options
262			* @todo PEAR::Cache for caching purposes!!!
263			* @todo refactor database access: use PEAR for this! no more 'connectdb' here!!!
264			* @todo make database connection more flexible to make possible
265			* to have different (probably named) proxy databases (besides a "main database")
266			* @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper?
267			* @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject)
268			* @todo rename this to "DesignPattern::LazyRemoteProxy"???
269	joko	1.1	*
270			*/
271			class DesignPattern_RemoteProxy extends DesignPattern_Proxy {
272
273			var $objectId;
274			// purpose ...
275			var $meta;
276			var $payload;
277			var $attributes;
278			var $backend;
279
280			function DesignPattern_RemoteProxy($objectId = "", $options = array() ) {
281	joko	1.15	php::log(get_class($this) . "->new()", PEAR_LOG_INFO);
282	joko	1.1	global $proxy;
283
284	joko	1.2	// 2003-03-05 - modified constructor
285			// expand objectId
286			if (is_array($objectId)) {
287			$options = $objectId[1];
288			$objectId = $objectId[0];
289			}
290
291	joko	1.1	// trace
292			//print Dumper($objectId, $options);
293
294			// initialization/startup
295			$this->_init_meta_options($objectId, $options);
296			$this->_init_caching();
297			$this->_init_load();
298
299	joko	1.2	//print Dumper($this);
300
301	joko	1.1	}
302
303			function _init_meta_options( $objectId="", $options = array() ) {
304			$this->meta = $options;
305
306			if ($objectId) {
307			$this->objectId = $objectId;
308
309			// set default load mechanism
310			if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) \|\| ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) {
311			$this->meta[oid] = 1;
312			}
313
314			}
315			}
316
317			function _init_caching() {
318
319			if ($this->meta[cache][session]) {
320			session_register_safe("proxy");
321			}
322	joko	1.7
323			/**
324			* <!-- Autodia -->
325			* can do: (this is metadata supplied for Autodia, don't delete!)
326			* $this->backend = new DataSource_Proxy_XMLRPC()
327			*
328			*/
329	joko	1.1
330			if ($this->meta[remote]) {
331			//$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]);
332	joko	1.2	$this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]);
333	joko	1.1	}
334			}
335
336			function _init_load() {
337			if ($this->objectId) {
338			$this->load();
339			//$this->_saveProxy();
340			}
341			}
342
343
344			function load() {
345	joko	1.15	php::log(get_class($this) . "->load()", PEAR_LOG_INFO);
346	joko	1.1	if (!$this->_loadState()) {
347			if (!$this->_loadProxy()) {
348
349			// just load object from remote side if its flagged to be a remote one ...
350			if ($this->meta[remote]) {
351			$this->_loadRemote();
352			}
353
354			}
355			}
356			}
357
358			function save($data, $type) {
359			$this->_setAttributes($data);
360			$this->_saveState();
361			if ($type == 'commit') {
362			$this->_commit();
363			}
364			if ($type == 'create') {
365			$this->_create();
366			}
367			}
368
369			function flush() {
370			$this->flushState();
371			$this->flushProxy();
372			}
373
374			function _commit() {
375			$this->_saveBackend($this->attributes);
376			$this->flushState();
377			$this->flushProxy();
378			}
379
380
381			// TODO: make this work
382			/*
383			function _create() {
384			$this->_createBackend($this->attributes);
385			$this->flushState();
386			$this->flushProxy();
387			}
388			*/
389
390	joko	1.2	function getResult() {
391	joko	1.1	if (!$this->meta[decoded]) {
392			$this->_decode();
393			$this->_saveState();
394			}
395			return $this->attributes;
396			}
397
398			function _setAttributes($data) {
399			$this->attributes = $data;
400	jonen	1.17	}
401
402			function getAttributes() {
403			return $this->attributes;
404	joko	1.1	}
405
406			function flushProxy() {
407			connectdb();
408			$sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'";
409			send_sql($sql);
410			}
411
412			function flushState() {
413			global $proxy;
414			unset($proxy[$this->objectId]);
415			$this->meta[decoded] = 0;
416			}
417
418			function _loadState() {
419			global $proxy;
420
421			// trace
422			//print Dumper($this);
423
424			// debug
425	joko	1.15	php::log(get_class($this) . "->_loadState()");
426	joko	1.1
427			if ($this->attributes = $proxy[$this->objectId]) {
428			//print "_loadState:" . dumpVar($this->attributes);
429			$this->meta[decoded] = 1;
430			// TODO: make a parameter from this (0 deactivates session-layer)
431			return 0;
432			}
433			}
434
435			function _saveState() {
436			global $proxy;
437	joko	1.15	php::log(get_class($this) . "->_saveState()");
438	joko	1.1	$proxy[$this->objectId] = $this->attributes;
439			//print "_saveState: " . dumpVar($this->attributes);
440			// TODO: throw exception-message back to user if operation fails
441			}
442
443			function _loadProxy() {
444
445			// FIXME!
446			if (!$this->meta[cache][db]) { return; }
447
448			// trace & debug
449			//print Dumper($this);
450	joko	1.15	php::log(get_class($this) . "->_loadProxy()");
451	joko	1.1
452			connectdb();
453			$sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
454			if ($res = send_sql($sql)) {
455			$row = mysql_fetch_array($res, MYSQL_ASSOC);
456			if ($row) {
457			$this->payload = $row[payload];
458			// TODO: make a parameter from this (0 deactivates mysqldb-layer)
459			return 0;
460			}
461			}
462			}
463
464			// TODO: use PEAR here
465			function _saveProxy() {
466
467			// FIXME!
468			if (!$this->meta[cache][db]) { return; }
469
470	joko	1.15	php::log(get_class($this) . "->_saveProxy()");
471	joko	1.1	connectdb();
472			if ($this->payload) {
473			//$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
474			$sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
475			if (!send_sql($sql)) {
476			$sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
477			send_sql($sql);
478			}
479			}
480			}
481
482			function _loadRemote() {
483	joko	1.15	php::log(get_class($this) . "->_loadRemote()");
484	joko	1.1
485			// trace
486			//print Dumper($this->meta);
487
488			// TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
489
490			// 1. check backend-handle
491			if (!$this->backend) {
492	joko	1.15	php::log(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
493	joko	1.1	return;
494			}
495
496			// determine backend action by metadata
497			// check for guid or oid
498			if ($this->meta[guid]) {
499			if (!$this->objectId) {
500	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
501	joko	1.1	return;
502			}
503			if (!$this->meta[classname]) {
504	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
505	joko	1.1	return;
506			}
507	joko	1.15	php::log(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
508	joko	1.1	$args = array( guid => $this->objectId, classname => $this->meta[classname] );
509	jonen	1.18	$result = $this->backend->send('getObjectByGuid', $args, array( utf8 => 1) );
510	joko	1.1
511			} elseif ($this->meta[oid]) {
512			if (!$this->objectId) {
513	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
514	joko	1.1	return;
515			}
516	joko	1.15	php::log(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
517	jonen	1.18	$result = $this->backend->send('getObject', $this->objectId, array( utf8 => 1) );
518	joko	1.1
519			} elseif ($this->meta[key]) {
520			if (!$this->meta[command]) {
521	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
522	joko	1.1	return;
523			}
524			/*
525			if (!$this->meta[query]) {
526	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
527	joko	1.1	return;
528			}
529			*/
530	joko	1.15	//php::log(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
531	joko	1.10	//print Dumper(array($this->meta[command], $this->meta[query]));
532	jonen	1.18	$result = $this->backend->send($this->meta[command], $this->meta[query], array( utf8 => 1) );
533	joko	1.1
534			}
535
536	joko	1.10	//print "result: " . dumpVar($result) . "<br>";
537	joko	1.1
538	joko	1.13	$status = $this->backend->status();
539	joko	1.10	//print Dumper($status);
540
541	joko	1.13	$good = is_array($result) && sizeof($result) && $status[connected];
542	joko	1.10
543	joko	1.13	if ($good) {
544	joko	1.1
545			// FIXME: this is dangerous!
546	joko	1.13	/*
547	joko	1.1	if ($_GET[debug]) {
548			print Dumper($result);
549			}
550	joko	1.13	*/
551	joko	1.1
552			$this->payload = serialize($result);
553			// ----- move this to _encode some times
554
555			$this->_saveProxy();
556			//print "oid: $this->objectId<br>";
557			$this->flushState();
558	joko	1.10
559	joko	1.1	} else {
560	joko	1.13
561			if (constants::get('APP_MODE_DEBUG')) {
562			$this->draw_error_box($status);
563	joko	1.11	} else {
564	joko	1.13	php::maintenance('rpc', array( status => $status ) );
565	joko	1.11	}
566	joko	1.10
567	joko	1.1	}
568
569			}
570	joko	1.13
571			function draw_error_box($status) {
572			$style = html_style("text/css", '.boxlabel_yellow { color: yellow; font-weight:bold; }');
573			$statusbox = html_div();
574			$statusbox->set_style('background: red; border: 2px black groove; width:640px; padding:10px; margin:40px;');
575			$statusbox->add( html_span('boxlabel_yellow', "Method:"), get_class($this) . "->_loadRemote", html_br() );
576			$statusbox->add( html_span('boxlabel_yellow', "Connected:"), $status[connected], html_br() );
577			$statusbox->add( html_span('boxlabel_yellow', "RPCSESSID:"), $status[RPCSESSID], html_br() );
578			foreach ($status[errors] as $error) {
579	joko	1.14	$msg = html_pre($error[message]);
580			$statusbox->add( html_span('boxlabel_yellow', "Error($error[code]):"), $msg );
581	joko	1.13	}
582	joko	1.1
583	joko	1.13	$message = "Error while talking to remote side. Please check wire, socket or api.";
584	joko	1.15	php::log($message, PEAR_LOG_CRIT);
585	joko	1.13	$statusbox->add( html_span('boxlabel_yellow', "Critical:"), $message, html_br() );
586
587			// V1
588			/*
589			if (constants::get('VERBOSE') \|\| constants::get('ERRORS_ONLY')) {
590			print $style->render();
591			print $statusbox->render();
592			} else {
593			foreach ($status[errors] as $error) {
594			print Dumper($error);
595			}
596			}
597			*/
598
599			// V2
600			trace( container($style, $statusbox) );
601
602			}
603
604
605	joko	1.1	function _saveBackend($result) {
606	joko	1.15	php::log(get_class($this) . "->_saveBackend()");
607	joko	1.1
608			//$encoder = new TextEncode($result);
609			//$encoder->toUTF8();
610
611			// check for guid or oid
612			if($this->meta[guid]) {
613			$args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result );
614			$response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) );
615			}
616			if($this->meta[oid]) {
617			$response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1) );
618			}
619			}
620
621			function _decode() {
622			// fill attributes-hashtable from message-hashtable
623			if (!$this->payload) { return; }
624			//if ($this->attributes = $backend->decodeData($this->payload)) {
625			if ($this->attributes = unserialize($this->payload)) {
626			$this->meta[decoded] = 1;
627			}
628			}
629
630			function store($struct) {
631			$this->payload = serialize($struct);
632			$this->_saveProxy();
633			}
634
635			}
636
637	jonen	1.16	?>
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