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 1.10 2003/03/28 03:05:54 joko Exp $
 * -------------------------------------------------------------------------
 *    $Log: RemoteProxy.php,v $
 *    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);
    
    if (constants::get('VERBOSE')) {
      $style = html_style("text/css", '.boxlabel_yellow { color: yellow; font-weight:bold; }');
      $statusbox = html_div();
      $statusbox->set_style('background: #558856; 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);
      if (constants::get('VERBOSE')) {
        $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')) {
        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	1.11	* $Id: RemoteProxy.php,v 1.10 2003/03/28 03:05:54 joko Exp $
19	joko	1.1	* -------------------------------------------------------------------------
20	joko	1.2	* $Log: RemoteProxy.php,v $
21	joko	1.11	* Revision 1.10 2003/03/28 03:05:54 joko
22			* more fancy debugging-output
23			*
24	joko	1.10	* Revision 1.9 2003/03/10 23:05:25 joko
25			* + fixed metadata for phpDocumentor
26			*
27	joko	1.9	* Revision 1.8 2003/03/10 22:31:56 joko
28			* + fixed metadata for phpDocumentor
29			*
30	joko	1.8	* Revision 1.7 2003/03/09 15:51:44 joko
31			* + additional metadata for Autodia
32			*
33	joko	1.7	* Revision 1.6 2003/03/05 17:28:43 joko
34			* updated docu (phpDocumentor testing....)
35			*
36	joko	1.6	* Revision 1.5 2003/03/05 17:02:22 joko
37			* updated docu (phpDocumentor testing....)
38			*
39	joko	1.5	* Revision 1.4 2003/03/05 16:32:19 joko
40			* updated docu (phpDocumentor testing....)
41			*
42	joko	1.4	* Revision 1.3 2003/03/05 16:10:17 joko
43			* updated docu (phpDocumentor testing....)
44			*
45	joko	1.3	* Revision 1.2 2003/03/05 12:14:02 joko
46			* renamed method
47			* constructor argument expansion
48			*
49	joko	1.2	* Revision 1.1 2003/03/03 22:06:46 joko
50			* refactored from Data::Driver::Proxy
51			*
52	joko	1.1	* Revision 1.3 2003/03/01 04:56:38 joko
53			* new comment style for large blocks - stolen from phpHtmlLib
54			* commit-log encapsulated into such a block
55			* introduced some documentation
56			* refactored todo (now also inside a stylish block)
57			*
58			* Revision 1.2 2003/02/13 21:48:09 joko
59			* + caching mechanisms more configurable now
60			*
61			* Revision 1.1 2003/02/09 17:23:21 joko
62			* + refactored from flib/Application/RPC/ProxyObject.php
63			*
64			* Revision 1.7 2003/02/03 03:31:38 jonen
65			* - moved '$encoder->toISO()' to 'Remote.php'
66			*
67			* Revision 1.6 2002/12/22 13:26:20 jonen
68			* + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
69			*
70			* Revision 1.5 2002/12/18 22:36:49 jonen
71			* + added support to get remote objects via backend via 'guid'
72			* + renamed '_loadBackend' to '_loadRemote'
73			* + constructor now accepts additional options:
74			* + remote: try to get object via '_loadRemote' ...
75			* + oid: use the given identifier as an 'oid' when doing '_loadRemote'
76			* + guid: use the given identifier as a 'guid' when doing '_loadRemote'
77			*
78			* Revision 1.4 2002/12/12 02:46:31 joko
79			* + state (session) gets flushed when data was successfully loaded from remote side
80			* + fixed _loadBackend
81			* + fixed flushState
82			*
83			* Revision 1.3 2002/12/06 04:12:54 joko
84			* + replaced 'xyzCache' through 'xyzProxy'
85			* + function store(...)
86			*
87			* Revision 1.2 2002/12/05 21:44:09 joko
88			* + debugging
89			*
90			* Revision 1.1 2002/12/01 17:23:58 joko
91			* + initial check-in
92			*
93			* Revision 1.11 2002/11/12 06:05:58 cvsjoko
94			* + renamed class: Text_Encode -> TextEncode
95			*
96			* Revision 1.10 2002/10/29 19:15:33 cvsjoko
97			* - moved utf8/iso-conversion to lib/utils/Text_Encode.php
98			*
99			* Revision 1.9 2002/10/26 12:32:36 cvsjoko
100			* - removed debugging via "print"
101			* + added generic logging via PEAR::Log
102			*
103			* Revision 1.8 2002/10/22 09:51:38 cvsmax
104			* + moved semi-method 'createBackend' to method $site->user->create at User.class.php
105			*
106			* Revision 1.7 2002/10/21 18:27:09 cvsjoko
107			* - manually disabled any form of caching
108			*
109			* Revision 1.6 2002/10/17 03:48:47 cvsmax
110			* + new
111			* + function _createBackend create new Backend
112			* + function _create api-create
113			*
114			* Revision 1.5 2002/10/16 03:37:54 cvsjoko
115			* + bugfix: wrong comparison in restriction to save to array
116			*
117			* Revision 1.4 2002/10/10 03:04:23 cvsjoko
118			* + no debug-output
119			*
120			* Revision 1.3 2002/10/10 03:03:27 cvsjoko
121			* + bugfix: save object to cache only if payload from backend isn't empty
122			*
123			* Revision 1.2 2002/10/10 02:40:06 cvsjoko
124			* + new level of data-caching (session and persistant)
125			* + function _loadState loads data from session
126			* + function _saveState saves data to session
127			* + function save api-save (session & backend)
128			* + function _commit saves data to backend
129			* + handy utils
130			* + function _setAttributes
131			* + function flushState
132			*
133			* Revision 1.1 2002/10/09 00:51:39 cvsjoko
134			* + new
135			* -------------------------------------------------------------------------
136	joko	1.4	* </pre>
137			*
138	joko	1.1	*/
139
140	joko	1.4
141
142
143			/**
144			* Load required modules:
145			*
146			*/
147			loadModule('DesignPattern::Proxy');
148
149
150	joko	1.1	/**
151	joko	1.7	* DesignPattern::RemoteProxy -- Multiple stage data fetching and caching
152	joko	1.1	*
153			*
154	joko	1.7	* This class (DesignPattern::RemoteProxy) provides an abstract framework
155	joko	1.1	* for loading/saving arbitrary data from/to data storages interfaced
156			* by storage proxy-drivers.
157			* Don't mix these up with the concrete storage handle-drivers
158			* doing the lowlevel stuff (opening files, talking sql, etc.).
159			* These proxy-drivers are "just" wrappers around them
160			* providing a more highlevel, consistent API making
161			* it easier for Data::Driver::Proxy to do its main work:
162			*
163	joko	1.7	* quote from: http://home.earthlink.net/~huston2/dp/proxy.html
164			* "A remote proxy provides a local representative for an
165			* object that resides in a different address space. This is
166			* what the "stub" code in RPC and CORBA provides."
167			*
168			*
169	joko	1.1	* Multiple stage data fetching and caching:
170			*
171	joko	1.4	* <pre>
172			*
173	joko	1.1	* DATA, ...
174			* ... also refered to as data, should be handled as
175			* something called data.
176			*
177			* STAGES
178			* x native php4 session: serialized payload
179			* x single rdbms table: serialized payload
180			* x ... via custom database wrapper
181			* x included php-file, included php-library
182			* o object, component, package, callbacks
183			* x ... via php PEAR DB abstraction objects
184			* x remote objects (items): flat attribute hash
185			* o use Data::Object::Identity
186			* o via Data::Driver::Proxy::RPC or others
187			* o Data::Object::Encoder: encodes/decodes values
188			* o Data::Object::Interpolator: interpolates/resolves references
189			*
190			* WORK
191			* x move data transparently around between these stages
192			*
193			* TOOLS
194			*
195			* x Overview - Packages, Handlers and Stages:
196			* This is weird. ;-)
197			* - A Package can be instantiated by its namespaced classname
198			* e.g.: "mkObject('My::Package');"
199			* - A Package can be a Handler for Data::Driver::Proxy
200			* - A Handler implements exactly one Stage
201			* - Data::Driver::Proxy itself embeds these Stages:
202			* x php4-session
203			* x rdbms-table
204			* - An example Handler is Data::Driver::RPC::Remote
205			*
206			* x Handlers:
207			* x Data::Driver::RPC::Remote
208			* Interacts with a RPC::XML server (todo: talk SOAP!)
209			* using PEAR::XML::RPC.
210			* It can cache data for "disconnected mode" using the
211			* o Data::Driver::phpHtmlLib
212			* o Data::Driver::PEAR::DB
213			* x Data::Driver::PEAR::Tree (via Data::Lift)
214			*
215	joko	1.4	* </pre>
216			*
217			*
218			* An attempt to implement some software design patterns
219	joko	1.3	* --- RemoteProxyPattern
220			*
221	joko	1.7	* @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm
222			* @link http://home.earthlink.net/~huston2/dp/proxy.html
223			* @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject
224	joko	1.3	* @link http://c2.com/cgi-bin/wiki?ProxyPattern
225	joko	1.7	* @link http://c2.com/cgi-bin/wiki?LazyProxies
226	joko	1.3	*
227			* @author Andreas Motl <andreas.motl@ilo.de>
228			* @link http://www.netfrag.org/~joko/
229			*
230			* @copyright (c) 2003 - All Rights reserved.
231			* @license GNU LGPL (GNU Lesser General Public License)
232			* @link http://www.gnu.org/licenses/lgpl.txt
233			*
234			* @package org.netfrag.glib
235	joko	1.6	* @subpackage DesignPattern
236	joko	1.3	* @name DesignPattern::RemoteProxy
237			*
238	joko	1.4	*
239	joko	1.7	* @todo extend options to en-/disable caching via a) session and/or b) database
240			* make feature available via runtime setter-method to these options
241			* @todo PEAR::Cache for caching purposes!!!
242			* @todo refactor database access: use PEAR for this! no more 'connectdb' here!!!
243			* @todo make database connection more flexible to make possible
244			* to have different (probably named) proxy databases (besides a "main database")
245			* @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper?
246			* @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject)
247			* @todo rename this to "DesignPattern::LazyRemoteProxy"???
248	joko	1.1	*
249			*/
250			class DesignPattern_RemoteProxy extends DesignPattern_Proxy {
251
252			var $objectId;
253			// purpose ...
254			var $meta;
255			var $payload;
256			var $attributes;
257			var $backend;
258
259			function DesignPattern_RemoteProxy($objectId = "", $options = array() ) {
260			logp(get_class($this) . "->new()", PEAR_LOG_INFO);
261			global $proxy;
262
263	joko	1.2	// 2003-03-05 - modified constructor
264			// expand objectId
265			if (is_array($objectId)) {
266			$options = $objectId[1];
267			$objectId = $objectId[0];
268			}
269
270	joko	1.1	// trace
271			//print Dumper($objectId, $options);
272
273			// initialization/startup
274			$this->_init_meta_options($objectId, $options);
275			$this->_init_caching();
276			$this->_init_load();
277
278	joko	1.2	//print Dumper($this);
279
280	joko	1.1	}
281
282			function _init_meta_options( $objectId="", $options = array() ) {
283			$this->meta = $options;
284
285			if ($objectId) {
286			$this->objectId = $objectId;
287
288			// set default load mechanism
289			if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) \|\| ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) {
290			$this->meta[oid] = 1;
291			}
292
293			}
294			}
295
296			function _init_caching() {
297
298			if ($this->meta[cache][session]) {
299			session_register_safe("proxy");
300			}
301	joko	1.7
302			/**
303			* <!-- Autodia -->
304			* can do: (this is metadata supplied for Autodia, don't delete!)
305			* $this->backend = new DataSource_Proxy_XMLRPC()
306			*
307			*/
308	joko	1.1
309			if ($this->meta[remote]) {
310			//$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]);
311	joko	1.2	$this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]);
312	joko	1.1	}
313			}
314
315			function _init_load() {
316			if ($this->objectId) {
317			$this->load();
318			//$this->_saveProxy();
319			}
320			}
321
322
323			function load() {
324			logp(get_class($this) . "->load()", PEAR_LOG_INFO);
325			if (!$this->_loadState()) {
326			if (!$this->_loadProxy()) {
327
328			// just load object from remote side if its flagged to be a remote one ...
329			if ($this->meta[remote]) {
330			$this->_loadRemote();
331			}
332
333			}
334			}
335			}
336
337			function save($data, $type) {
338			$this->_setAttributes($data);
339			$this->_saveState();
340			if ($type == 'commit') {
341			$this->_commit();
342			}
343			if ($type == 'create') {
344			$this->_create();
345			}
346			}
347
348			function flush() {
349			$this->flushState();
350			$this->flushProxy();
351			}
352
353			function _commit() {
354			$this->_saveBackend($this->attributes);
355			$this->flushState();
356			$this->flushProxy();
357			}
358
359
360			// TODO: make this work
361			/*
362			function _create() {
363			$this->_createBackend($this->attributes);
364			$this->flushState();
365			$this->flushProxy();
366			}
367			*/
368
369	joko	1.2	function getResult() {
370	joko	1.1	if (!$this->meta[decoded]) {
371			$this->_decode();
372			$this->_saveState();
373			}
374			return $this->attributes;
375			}
376
377			function _setAttributes($data) {
378			$this->attributes = $data;
379			}
380
381			function flushProxy() {
382			connectdb();
383			$sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'";
384			send_sql($sql);
385			}
386
387			function flushState() {
388			global $proxy;
389			unset($proxy[$this->objectId]);
390			$this->meta[decoded] = 0;
391			}
392
393			function _loadState() {
394			global $proxy;
395
396			// trace
397			//print Dumper($this);
398
399			// debug
400			logp(get_class($this) . "->_loadState()");
401
402			if ($this->attributes = $proxy[$this->objectId]) {
403			//print "_loadState:" . dumpVar($this->attributes);
404			$this->meta[decoded] = 1;
405			// TODO: make a parameter from this (0 deactivates session-layer)
406			return 0;
407			}
408			}
409
410			function _saveState() {
411			global $proxy;
412			logp(get_class($this) . "->_saveState()");
413			$proxy[$this->objectId] = $this->attributes;
414			//print "_saveState: " . dumpVar($this->attributes);
415			// TODO: throw exception-message back to user if operation fails
416			}
417
418			function _loadProxy() {
419
420			// FIXME!
421			if (!$this->meta[cache][db]) { return; }
422
423			// trace & debug
424			//print Dumper($this);
425			logp(get_class($this) . "->_loadProxy()");
426
427			connectdb();
428			$sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
429			if ($res = send_sql($sql)) {
430			$row = mysql_fetch_array($res, MYSQL_ASSOC);
431			if ($row) {
432			$this->payload = $row[payload];
433			// TODO: make a parameter from this (0 deactivates mysqldb-layer)
434			return 0;
435			}
436			}
437			}
438
439			// TODO: use PEAR here
440			function _saveProxy() {
441
442			// FIXME!
443			if (!$this->meta[cache][db]) { return; }
444
445			logp(get_class($this) . "->_saveProxy()");
446			connectdb();
447			if ($this->payload) {
448			//$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
449			$sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
450			if (!send_sql($sql)) {
451			$sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
452			send_sql($sql);
453			}
454			}
455			}
456
457			function _loadRemote() {
458			logp(get_class($this) . "->_loadRemote()");
459
460			// trace
461			//print Dumper($this->meta);
462
463			// TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
464
465			// 1. check backend-handle
466			if (!$this->backend) {
467			logp(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
468			return;
469			}
470
471			// determine backend action by metadata
472			// check for guid or oid
473			if ($this->meta[guid]) {
474			if (!$this->objectId) {
475			logp(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
476			return;
477			}
478			if (!$this->meta[classname]) {
479			logp(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
480			return;
481			}
482	joko	1.10	logp(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
483	joko	1.1	$args = array( guid => $this->objectId, classname => $this->meta[classname] );
484			$result = $this->backend->send('getObjectByGuid', $args );
485
486			} elseif ($this->meta[oid]) {
487			if (!$this->objectId) {
488			logp(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
489			return;
490			}
491	joko	1.10	logp(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
492	joko	1.1	$result = $this->backend->send('getObject', $this->objectId);
493
494			} elseif ($this->meta[key]) {
495			if (!$this->meta[command]) {
496			logp(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
497			return;
498			}
499			/*
500			if (!$this->meta[query]) {
501			logp(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
502			return;
503			}
504			*/
505	joko	1.10	//logp(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
506			//print Dumper(array($this->meta[command], $this->meta[query]));
507	joko	1.1	$result = $this->backend->send($this->meta[command], $this->meta[query]);
508
509			}
510
511	joko	1.10	//print "result: " . dumpVar($result) . "<br>";
512	joko	1.1
513	joko	1.10	$status = $this->backend->getStatus();
514			//print Dumper($status);
515
516	joko	1.11	if (constants::get('VERBOSE')) {
517			$style = html_style("text/css", '.boxlabel_yellow { color: yellow; font-weight:bold; }');
518			$statusbox = html_div();
519			$statusbox->set_style('background: #558856; border: 2px black groove; width:640px; padding:10px; margin:40px;');
520			$statusbox->add( html_span('boxlabel_yellow', "Connected:"), $status[connected], html_br() );
521			foreach ($status[errors] as $error) {
522			$statusbox->add( html_span('boxlabel_yellow', "Error($error[code]):"), $error[message], html_br() );
523			}
524	joko	1.10	}
525	joko	1.1
526	joko	1.10	if (is_array($result)) {
527			$good = 1;
528			} else {
529			$message = get_class($this) . "->_loadRemote: Error while trying to talk to remote side. Please check wire, socket or api.";
530			logp($message, PEAR_LOG_CRIT);
531	joko	1.11	if (constants::get('VERBOSE')) {
532			$statusbox->add( html_span('boxlabel_yellow', "Critical:"), $message, html_br() );
533			}
534	joko	1.10	}
535
536			if ($good && sizeof($result)) {
537	joko	1.1
538			// FIXME: this is dangerous!
539			if ($_GET[debug]) {
540			print Dumper($result);
541			}
542
543			$this->payload = serialize($result);
544			// ----- move this to _encode some times
545
546			$this->_saveProxy();
547			//print "oid: $this->objectId<br>";
548			$this->flushState();
549	joko	1.10
550	joko	1.1	} else {
551	joko	1.11	if (constants::get('VERBOSE')) {
552			print $style->render();
553			print $statusbox->render();
554			} else {
555			foreach ($status[errors] as $error) {
556			print Dumper($error);
557			}
558			}
559	joko	1.10
560	joko	1.1	}
561
562			}
563
564			function _saveBackend($result) {
565			logp(get_class($this) . "->_saveBackend()");
566
567			//$encoder = new TextEncode($result);
568			//$encoder->toUTF8();
569
570			// check for guid or oid
571			if($this->meta[guid]) {
572			$args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result );
573			$response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) );
574			}
575			if($this->meta[oid]) {
576			$response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1) );
577			}
578			}
579
580			function _decode() {
581			// fill attributes-hashtable from message-hashtable
582			if (!$this->payload) { return; }
583			//if ($this->attributes = $backend->decodeData($this->payload)) {
584			if ($this->attributes = unserialize($this->payload)) {
585			$this->meta[decoded] = 1;
586			}
587			}
588
589			function store($struct) {
590			$this->payload = serialize($struct);
591			$this->_saveProxy();
592			}
593
594			}
595
596			?>
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