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 1.11 2003/03/28 06:44:51 joko Exp $
 * -------------------------------------------------------------------------
 *    $Log: RemoteProxy.php,v $
 *    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 = $this->backend->getStatus();
    //print Dumper($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', "Connected:"), $status[connected], html_br() );
    foreach ($status[errors] as $error) {
      $statusbox->add( html_span('boxlabel_yellow', "Error($error[code]):"), $error[message], html_br() );
    }
    
    if (is_array($result)) {
      $good = 1;
    } else {
      $message = get_class($this) . "->_loadRemote: Error while trying to talk to remote side. Please check wire, socket or api.";
      logp($message, PEAR_LOG_CRIT);
      $statusbox->add( html_span('boxlabel_yellow', "Critical:"), $message, html_br() );
    }

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