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 1.13 2003/04/04 17:38:03 joko Exp $
 * -------------------------------------------------------------------------
 *    $Log: RemoteProxy.php,v $
 *    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 = "", $options = array() ) {
    logp(get_class($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() {
    logp(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 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
      logp(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 $proxy;
    logp(get_class($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($this);
      logp(get_class($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; }

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

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