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 1.19 2004/06/07 16:56:45 joko Exp $
 * -------------------------------------------------------------------------
 *    $Log: RemoteProxy.php,v $
 *    Revision 1.19  2004/06/07 16:56:45  joko
 *    enabled caching-layers
 *    minor fixes regarding caching
 *
 *    Revision 1.18  2004/05/13 19:17:55  jonen
 *    + bugfix: utf8 conversion was missing at some backend-calls
 *
 *    Revision 1.17  2003/07/14 10:05:23  jonen
 *    bugfix: added *needed* function 'getAttributes'
 *
 *    Revision 1.16  2003/07/02 13:51:38  jonen
 *    removed debug dumper
 *
 *    Revision 1.15  2003/04/11 01:32:21  joko
 *    renamed logging function
 *
 *    Revision 1.14  2003/04/09 02:06:45  joko
 *    errormessage now shown preformatted
 *
 *    Revision 1.13  2003/04/04 17:38:03  joko
 *    modifications regarding error-/exception-handling and -tracing
 *
 *    Revision 1.12  2003/03/29 08:01:21  joko
 *    modified ErrorBoxing
 *
 *    Revision 1.11  2003/03/28 06:44:51  joko
 *    VERBOSE mode
 *
 *    Revision 1.10  2003/03/28 03:05:54  joko
 *    more fancy debugging-output
 *
 *    Revision 1.9  2003/03/10 23:05:25  joko
 *    + fixed metadata for phpDocumentor
 *
 *    Revision 1.8  2003/03/10 22:31:56  joko
 *    + fixed metadata for phpDocumentor
 *
 *    Revision 1.7  2003/03/09 15:51:44  joko
 *    + additional metadata for Autodia
 *
 *    Revision 1.6  2003/03/05 17:28:43  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.5  2003/03/05 17:02:22  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.4  2003/03/05 16:32:19  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.3  2003/03/05 16:10:17  joko
 *    updated docu (phpDocumentor testing....)
 *
 *    Revision 1.2  2003/03/05 12:14:02  joko
 *    renamed method
 *    constructor argument expansion
 *
 *    Revision 1.1  2003/03/03 22:06:46  joko
 *    refactored from Data::Driver::Proxy
 *
 *    Revision 1.3  2003/03/01 04:56:38  joko
 *    new comment style for large blocks - stolen from phpHtmlLib
 *    commit-log encapsulated into such a block
 *    introduced some documentation
 *    refactored todo (now also inside a stylish block)
 *
 *    Revision 1.2  2003/02/13 21:48:09  joko
 *    + caching mechanisms more configurable now
 *
 *    Revision 1.1  2003/02/09 17:23:21  joko
 *    + refactored from flib/Application/RPC/ProxyObject.php
 *
 *    Revision 1.7  2003/02/03 03:31:38  jonen
 *    - moved '$encoder->toISO()' to 'Remote.php'
 *
 *    Revision 1.6  2002/12/22 13:26:20  jonen
 *    + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
 *
 *    Revision 1.5  2002/12/18 22:36:49  jonen
 *    + added support to get remote objects via backend via 'guid'
 *    + renamed '_loadBackend' to '_loadRemote'
 *    + constructor now accepts additional options:
 *      + remote: try to get object via '_loadRemote' ...
 *      + oid: use the given identifier as an 'oid' when doing '_loadRemote'
 *      + guid: use the given identifier as a 'guid' when doing '_loadRemote'
 *
 *    Revision 1.4  2002/12/12 02:46:31  joko
 *    + state (session) gets flushed when data was successfully loaded from remote side
 *    + fixed _loadBackend
 *    + fixed flushState
 *
 *    Revision 1.3  2002/12/06 04:12:54  joko
 *    + replaced 'xyzCache' through 'xyzProxy'
 *    + function store(...)
 *
 *    Revision 1.2  2002/12/05 21:44:09  joko
 *    + debugging
 *
 *    Revision 1.1  2002/12/01 17:23:58  joko
 *    + initial check-in
 *
 *    Revision 1.11  2002/11/12 06:05:58  cvsjoko
 *    + renamed class: Text_Encode -> TextEncode
 *
 *    Revision 1.10  2002/10/29 19:15:33  cvsjoko
 *    - moved utf8/iso-conversion to lib/utils/Text_Encode.php
 *
 *    Revision 1.9  2002/10/26 12:32:36  cvsjoko
 *    - removed debugging via "print"
 *    + added generic logging via PEAR::Log
 *
 *    Revision 1.8  2002/10/22 09:51:38  cvsmax
 *    + moved semi-method 'createBackend' to method $site->user->create at User.class.php
 *
 *    Revision 1.7  2002/10/21 18:27:09  cvsjoko
 *    - manually disabled any form of caching
 *
 *    Revision 1.6  2002/10/17 03:48:47  cvsmax
 *    + new
 *       + function _createBackend      create new Backend
 *       + function _create             api-create
 *
 *    Revision 1.5  2002/10/16 03:37:54  cvsjoko
 *    + bugfix: wrong comparison in restriction to save to array
 *
 *    Revision 1.4  2002/10/10 03:04:23  cvsjoko
 *    + no debug-output
 *
 *    Revision 1.3  2002/10/10 03:03:27  cvsjoko
 *    + bugfix: save object to cache only if payload from backend isn't empty
 *
 *    Revision 1.2  2002/10/10 02:40:06  cvsjoko
 *    + new level of data-caching (session and persistant)
 *        + function _loadState loads data from session
 *        + function _saveState saves data to session
 *        + function save               api-save (session & backend)
 *        + function _commit    saves data to backend
 *    + handy utils
 *        + function _setAttributes
 *        + function flushState
 *
 *    Revision 1.1  2002/10/09 00:51:39  cvsjoko
 *    + new
 * -------------------------------------------------------------------------
 * </pre>
 *
 */


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


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

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

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

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

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

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

    //print Dumper($this);

  }

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

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

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

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

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

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


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

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

      }
    }
  }  

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

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

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


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

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

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

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

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

  function _loadState() {
    global $proxy;

    // just do session-caching if requested
    if (!$this->meta[cache][session]) { return; }

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

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

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

  function _loadProxy() {
    
    // FIXME!
    if (!$this->meta[cache][db]) { return; }
    
    // trace & debug
      //print Dumper($this);
      php::log(get_class($this) . "->_loadProxy()");
      
    connectdb();
    $sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
    if ($res = send_sql($sql)) {
      $row = mysql_fetch_array($res, MYSQL_ASSOC);
      if ($row) {
        $this->payload = $row[payload];
        // TODO: make a parameter from this (0 deactivates mysqldb-layer)
        return 1;
      }
    }
  }
  
  // TODO: use PEAR here
  function _saveProxy() {

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

    php::log(get_class($this) . "->_saveProxy()");
        connectdb();
        if ($this->payload) {
      //$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
      $sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
      if (!send_sql($sql)) {
        $sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
        send_sql($sql);
      }
    }
  }
  
  function _loadRemote() {
    php::log(get_class($this) . "->_loadRemote()");
    
    // trace
      //print Dumper($this->meta);
        
    // TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
    
    // 1. check backend-handle
    if (!$this->backend) {
      php::log(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
      return;
    }
    
    // determine backend action by metadata
      // check for guid or oid
      if ($this->meta[guid]) {
        if (!$this->objectId) {
          php::log(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
          return;
        }
        if (!$this->meta[classname]) {
          php::log(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
          return;
        }
        php::log(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
        $args = array( guid => $this->objectId, classname => $this->meta[classname] );
        $result = $this->backend->send('getObjectByGuid', $args, array( utf8 => 1)  );

      } elseif ($this->meta[oid]) {
        if (!$this->objectId) {
          php::log(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
          return;
        }
        php::log(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
        $result = $this->backend->send('getObject', $this->objectId, array( utf8 => 1) );

      } elseif ($this->meta[key]) {
        if (!$this->meta[command]) {
          php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
          return;
        }
        /*
        if (!$this->meta[query]) {
          php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
          return;
        }
        */
        //php::log(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
        //print Dumper(array($this->meta[command], $this->meta[query]));
        $result = $this->backend->send($this->meta[command], $this->meta[query], array( utf8 => 1) );
        
      }

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

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

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

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

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

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

}  


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

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

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

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

}

?>
1	joko	1.1	<?php
2	joko	1.3	/**
3			* This file contains the DesignPattern::RemoteProxy class
4			*
5			* @author Andreas Motl <andreas.motl@ilo.de>
6			* @package org.netfrag.glib
7			* @name DesignPattern::RemoteProxy
8			*
9	joko	1.4	*
10	joko	1.9	*/
11
12
13			/**
14	joko	1.4	* <b>Cvs-Log:</b>
15			*
16			* <pre>
17	joko	1.1	* -------------------------------------------------------------------------
18	joko	1.20	* $Id: RemoteProxy.php,v 1.19 2004/06/07 16:56:45 joko Exp $
19	joko	1.1	* -------------------------------------------------------------------------
20	joko	1.2	* $Log: RemoteProxy.php,v $
21	joko	1.20	* Revision 1.19 2004/06/07 16:56:45 joko
22			* enabled caching-layers
23			* minor fixes regarding caching
24			*
25	joko	1.19	* Revision 1.18 2004/05/13 19:17:55 jonen
26			* + bugfix: utf8 conversion was missing at some backend-calls
27			*
28	jonen	1.18	* Revision 1.17 2003/07/14 10:05:23 jonen
29			* bugfix: added needed function 'getAttributes'
30			*
31	jonen	1.17	* Revision 1.16 2003/07/02 13:51:38 jonen
32			* removed debug dumper
33			*
34	jonen	1.16	* Revision 1.15 2003/04/11 01:32:21 joko
35			* renamed logging function
36			*
37	joko	1.15	* Revision 1.14 2003/04/09 02:06:45 joko
38			* errormessage now shown preformatted
39			*
40	joko	1.14	* Revision 1.13 2003/04/04 17:38:03 joko
41			* modifications regarding error-/exception-handling and -tracing
42			*
43	joko	1.13	* Revision 1.12 2003/03/29 08:01:21 joko
44			* modified ErrorBoxing
45			*
46	joko	1.12	* Revision 1.11 2003/03/28 06:44:51 joko
47			* VERBOSE mode
48			*
49	joko	1.11	* Revision 1.10 2003/03/28 03:05:54 joko
50			* more fancy debugging-output
51			*
52	joko	1.10	* Revision 1.9 2003/03/10 23:05:25 joko
53			* + fixed metadata for phpDocumentor
54			*
55	joko	1.9	* Revision 1.8 2003/03/10 22:31:56 joko
56			* + fixed metadata for phpDocumentor
57			*
58	joko	1.8	* Revision 1.7 2003/03/09 15:51:44 joko
59			* + additional metadata for Autodia
60			*
61	joko	1.7	* Revision 1.6 2003/03/05 17:28:43 joko
62			* updated docu (phpDocumentor testing....)
63			*
64	joko	1.6	* Revision 1.5 2003/03/05 17:02:22 joko
65			* updated docu (phpDocumentor testing....)
66			*
67	joko	1.5	* Revision 1.4 2003/03/05 16:32:19 joko
68			* updated docu (phpDocumentor testing....)
69			*
70	joko	1.4	* Revision 1.3 2003/03/05 16:10:17 joko
71			* updated docu (phpDocumentor testing....)
72			*
73	joko	1.3	* Revision 1.2 2003/03/05 12:14:02 joko
74			* renamed method
75			* constructor argument expansion
76			*
77	joko	1.2	* Revision 1.1 2003/03/03 22:06:46 joko
78			* refactored from Data::Driver::Proxy
79			*
80	joko	1.1	* Revision 1.3 2003/03/01 04:56:38 joko
81			* new comment style for large blocks - stolen from phpHtmlLib
82			* commit-log encapsulated into such a block
83			* introduced some documentation
84			* refactored todo (now also inside a stylish block)
85			*
86			* Revision 1.2 2003/02/13 21:48:09 joko
87			* + caching mechanisms more configurable now
88			*
89			* Revision 1.1 2003/02/09 17:23:21 joko
90			* + refactored from flib/Application/RPC/ProxyObject.php
91			*
92			* Revision 1.7 2003/02/03 03:31:38 jonen
93			* - moved '$encoder->toISO()' to 'Remote.php'
94			*
95			* Revision 1.6 2002/12/22 13:26:20 jonen
96			* + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor
97			*
98			* Revision 1.5 2002/12/18 22:36:49 jonen
99			* + added support to get remote objects via backend via 'guid'
100			* + renamed '_loadBackend' to '_loadRemote'
101			* + constructor now accepts additional options:
102			* + remote: try to get object via '_loadRemote' ...
103			* + oid: use the given identifier as an 'oid' when doing '_loadRemote'
104			* + guid: use the given identifier as a 'guid' when doing '_loadRemote'
105			*
106			* Revision 1.4 2002/12/12 02:46:31 joko
107			* + state (session) gets flushed when data was successfully loaded from remote side
108			* + fixed _loadBackend
109			* + fixed flushState
110			*
111			* Revision 1.3 2002/12/06 04:12:54 joko
112			* + replaced 'xyzCache' through 'xyzProxy'
113			* + function store(...)
114			*
115			* Revision 1.2 2002/12/05 21:44:09 joko
116			* + debugging
117			*
118			* Revision 1.1 2002/12/01 17:23:58 joko
119			* + initial check-in
120			*
121			* Revision 1.11 2002/11/12 06:05:58 cvsjoko
122			* + renamed class: Text_Encode -> TextEncode
123			*
124			* Revision 1.10 2002/10/29 19:15:33 cvsjoko
125			* - moved utf8/iso-conversion to lib/utils/Text_Encode.php
126			*
127			* Revision 1.9 2002/10/26 12:32:36 cvsjoko
128			* - removed debugging via "print"
129			* + added generic logging via PEAR::Log
130			*
131			* Revision 1.8 2002/10/22 09:51:38 cvsmax
132			* + moved semi-method 'createBackend' to method $site->user->create at User.class.php
133			*
134			* Revision 1.7 2002/10/21 18:27:09 cvsjoko
135			* - manually disabled any form of caching
136			*
137			* Revision 1.6 2002/10/17 03:48:47 cvsmax
138			* + new
139			* + function _createBackend create new Backend
140			* + function _create api-create
141			*
142			* Revision 1.5 2002/10/16 03:37:54 cvsjoko
143			* + bugfix: wrong comparison in restriction to save to array
144			*
145			* Revision 1.4 2002/10/10 03:04:23 cvsjoko
146			* + no debug-output
147			*
148			* Revision 1.3 2002/10/10 03:03:27 cvsjoko
149			* + bugfix: save object to cache only if payload from backend isn't empty
150			*
151			* Revision 1.2 2002/10/10 02:40:06 cvsjoko
152			* + new level of data-caching (session and persistant)
153			* + function _loadState loads data from session
154			* + function _saveState saves data to session
155			* + function save api-save (session & backend)
156			* + function _commit saves data to backend
157			* + handy utils
158			* + function _setAttributes
159			* + function flushState
160			*
161			* Revision 1.1 2002/10/09 00:51:39 cvsjoko
162			* + new
163			* -------------------------------------------------------------------------
164	joko	1.4	* </pre>
165			*
166	joko	1.1	*/
167
168	joko	1.4
169
170
171			/**
172			* Load required modules:
173			*
174			*/
175			loadModule('DesignPattern::Proxy');
176
177
178	joko	1.1	/**
179	joko	1.7	* DesignPattern::RemoteProxy -- Multiple stage data fetching and caching
180	joko	1.1	*
181			*
182	joko	1.7	* This class (DesignPattern::RemoteProxy) provides an abstract framework
183	joko	1.1	* for loading/saving arbitrary data from/to data storages interfaced
184			* by storage proxy-drivers.
185			* Don't mix these up with the concrete storage handle-drivers
186			* doing the lowlevel stuff (opening files, talking sql, etc.).
187			* These proxy-drivers are "just" wrappers around them
188			* providing a more highlevel, consistent API making
189			* it easier for Data::Driver::Proxy to do its main work:
190			*
191	joko	1.7	* quote from: http://home.earthlink.net/~huston2/dp/proxy.html
192			* "A remote proxy provides a local representative for an
193			* object that resides in a different address space. This is
194			* what the "stub" code in RPC and CORBA provides."
195			*
196			*
197	joko	1.1	* Multiple stage data fetching and caching:
198			*
199	joko	1.4	* <pre>
200			*
201	joko	1.1	* DATA, ...
202			* ... also refered to as data, should be handled as
203			* something called data.
204			*
205			* STAGES
206			* x native php4 session: serialized payload
207			* x single rdbms table: serialized payload
208			* x ... via custom database wrapper
209			* x included php-file, included php-library
210			* o object, component, package, callbacks
211			* x ... via php PEAR DB abstraction objects
212			* x remote objects (items): flat attribute hash
213			* o use Data::Object::Identity
214			* o via Data::Driver::Proxy::RPC or others
215			* o Data::Object::Encoder: encodes/decodes values
216			* o Data::Object::Interpolator: interpolates/resolves references
217			*
218			* WORK
219			* x move data transparently around between these stages
220			*
221			* TOOLS
222			*
223			* x Overview - Packages, Handlers and Stages:
224			* This is weird. ;-)
225			* - A Package can be instantiated by its namespaced classname
226			* e.g.: "mkObject('My::Package');"
227			* - A Package can be a Handler for Data::Driver::Proxy
228			* - A Handler implements exactly one Stage
229			* - Data::Driver::Proxy itself embeds these Stages:
230			* x php4-session
231			* x rdbms-table
232			* - An example Handler is Data::Driver::RPC::Remote
233			*
234			* x Handlers:
235			* x Data::Driver::RPC::Remote
236			* Interacts with a RPC::XML server (todo: talk SOAP!)
237			* using PEAR::XML::RPC.
238			* It can cache data for "disconnected mode" using the
239			* o Data::Driver::phpHtmlLib
240			* o Data::Driver::PEAR::DB
241			* x Data::Driver::PEAR::Tree (via Data::Lift)
242			*
243	joko	1.4	* </pre>
244			*
245			*
246			* An attempt to implement some software design patterns
247	joko	1.3	* --- RemoteProxyPattern
248			*
249	joko	1.7	* @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm
250			* @link http://home.earthlink.net/~huston2/dp/proxy.html
251			* @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject
252	joko	1.3	* @link http://c2.com/cgi-bin/wiki?ProxyPattern
253	joko	1.7	* @link http://c2.com/cgi-bin/wiki?LazyProxies
254	joko	1.3	*
255			* @author Andreas Motl <andreas.motl@ilo.de>
256			* @link http://www.netfrag.org/~joko/
257			*
258			* @copyright (c) 2003 - All Rights reserved.
259			* @license GNU LGPL (GNU Lesser General Public License)
260			* @link http://www.gnu.org/licenses/lgpl.txt
261			*
262			* @package org.netfrag.glib
263	joko	1.6	* @subpackage DesignPattern
264	joko	1.3	* @name DesignPattern::RemoteProxy
265			*
266	joko	1.4	*
267	joko	1.7	* @todo extend options to en-/disable caching via a) session and/or b) database
268			* make feature available via runtime setter-method to these options
269			* @todo PEAR::Cache for caching purposes!!!
270			* @todo refactor database access: use PEAR for this! no more 'connectdb' here!!!
271			* @todo make database connection more flexible to make possible
272			* to have different (probably named) proxy databases (besides a "main database")
273			* @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper?
274			* @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject)
275			* @todo rename this to "DesignPattern::LazyRemoteProxy"???
276	joko	1.1	*
277			*/
278			class DesignPattern_RemoteProxy extends DesignPattern_Proxy {
279
280			var $objectId;
281			// purpose ...
282			var $meta;
283			var $payload;
284			var $attributes;
285			var $backend;
286
287			function DesignPattern_RemoteProxy($objectId = "", $options = array() ) {
288	joko	1.19	php::log(get_class($this) . "->new(objectId=$objectId)", PEAR_LOG_INFO);
289	joko	1.1	global $proxy;
290
291	joko	1.2	// 2003-03-05 - modified constructor
292			// expand objectId
293			if (is_array($objectId)) {
294			$options = $objectId[1];
295			$objectId = $objectId[0];
296			}
297
298	joko	1.1	// trace
299			//print Dumper($objectId, $options);
300
301			// initialization/startup
302			$this->_init_meta_options($objectId, $options);
303			$this->_init_caching();
304			$this->_init_load();
305
306	joko	1.2	//print Dumper($this);
307
308	joko	1.1	}
309
310			function _init_meta_options( $objectId="", $options = array() ) {
311			$this->meta = $options;
312
313			if ($objectId) {
314			$this->objectId = $objectId;
315
316			// set default load mechanism
317			if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) \|\| ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) {
318			$this->meta[oid] = 1;
319			}
320
321			}
322			}
323
324			function _init_caching() {
325
326			if ($this->meta[cache][session]) {
327			session_register_safe("proxy");
328			}
329	joko	1.7
330			/**
331			* <!-- Autodia -->
332			* can do: (this is metadata supplied for Autodia, don't delete!)
333			* $this->backend = new DataSource_Proxy_XMLRPC()
334			*
335			*/
336	joko	1.1
337			if ($this->meta[remote]) {
338			//$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]);
339	joko	1.2	$this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]);
340	joko	1.1	}
341			}
342
343			function _init_load() {
344			if ($this->objectId) {
345			$this->load();
346			//$this->_saveProxy();
347			}
348			}
349
350
351			function load() {
352	joko	1.15	php::log(get_class($this) . "->load()", PEAR_LOG_INFO);
353	joko	1.1	if (!$this->_loadState()) {
354			if (!$this->_loadProxy()) {
355
356			// just load object from remote side if its flagged to be a remote one ...
357			if ($this->meta[remote]) {
358			$this->_loadRemote();
359			}
360
361			}
362			}
363			}
364
365			function save($data, $type) {
366			$this->_setAttributes($data);
367			$this->_saveState();
368			if ($type == 'commit') {
369			$this->_commit();
370			}
371			if ($type == 'create') {
372			$this->_create();
373			}
374			}
375
376			function flush() {
377			$this->flushState();
378			$this->flushProxy();
379			}
380
381			function _commit() {
382			$this->_saveBackend($this->attributes);
383			$this->flushState();
384			$this->flushProxy();
385			}
386
387
388			// TODO: make this work
389			/*
390			function _create() {
391			$this->_createBackend($this->attributes);
392			$this->flushState();
393			$this->flushProxy();
394			}
395			*/
396
397	joko	1.2	function getResult() {
398	joko	1.1	if (!$this->meta[decoded]) {
399			$this->_decode();
400			$this->_saveState();
401			}
402			return $this->attributes;
403			}
404
405			function _setAttributes($data) {
406			$this->attributes = $data;
407	jonen	1.17	}
408
409			function getAttributes() {
410			return $this->attributes;
411	joko	1.1	}
412
413			function flushProxy() {
414			connectdb();
415			$sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'";
416			send_sql($sql);
417			}
418
419			function flushState() {
420			global $proxy;
421			unset($proxy[$this->objectId]);
422			$this->meta[decoded] = 0;
423			}
424
425			function _loadState() {
426			global $proxy;
427
428	joko	1.19	// just do session-caching if requested
429			if (!$this->meta[cache][session]) { return; }
430
431	joko	1.1	// trace
432			//print Dumper($this);
433
434			// debug
435	joko	1.15	php::log(get_class($this) . "->_loadState()");
436	joko	1.1
437			if ($this->attributes = $proxy[$this->objectId]) {
438			//print "_loadState:" . dumpVar($this->attributes);
439			$this->meta[decoded] = 1;
440			// TODO: make a parameter from this (0 deactivates session-layer)
441	joko	1.19	return 1;
442	joko	1.1	}
443			}
444
445			function _saveState() {
446			global $proxy;
447	joko	1.19
448			// just do session-caching if requested
449			if (!$this->meta[cache][session]) { return; }
450
451	joko	1.15	php::log(get_class($this) . "->_saveState()");
452	joko	1.1	$proxy[$this->objectId] = $this->attributes;
453			//print "_saveState: " . dumpVar($this->attributes);
454			// TODO: throw exception-message back to user if operation fails
455			}
456
457			function _loadProxy() {
458
459			// FIXME!
460			if (!$this->meta[cache][db]) { return; }
461
462			// trace & debug
463			//print Dumper($this);
464	joko	1.15	php::log(get_class($this) . "->_loadProxy()");
465	joko	1.1
466			connectdb();
467			$sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'";
468			if ($res = send_sql($sql)) {
469			$row = mysql_fetch_array($res, MYSQL_ASSOC);
470			if ($row) {
471			$this->payload = $row[payload];
472			// TODO: make a parameter from this (0 deactivates mysqldb-layer)
473	joko	1.19	return 1;
474	joko	1.1	}
475			}
476			}
477
478			// TODO: use PEAR here
479			function _saveProxy() {
480
481			// FIXME!
482			if (!$this->meta[cache][db]) { return; }
483
484	joko	1.15	php::log(get_class($this) . "->_saveProxy()");
485	joko	1.1	connectdb();
486			if ($this->payload) {
487			//$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
488			$sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'";
489			if (!send_sql($sql)) {
490			$sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'";
491			send_sql($sql);
492			}
493			}
494			}
495
496			function _loadRemote() {
497	joko	1.15	php::log(get_class($this) . "->_loadRemote()");
498	joko	1.1
499			// trace
500			//print Dumper($this->meta);
501
502			// TODO: test backend for reachability first (eventually cache this information and "reset" it by another party)
503
504			// 1. check backend-handle
505			if (!$this->backend) {
506	joko	1.15	php::log(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT);
507	joko	1.1	return;
508			}
509
510			// determine backend action by metadata
511			// check for guid or oid
512			if ($this->meta[guid]) {
513			if (!$this->objectId) {
514	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING);
515	joko	1.1	return;
516			}
517			if (!$this->meta[classname]) {
518	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING);
519	joko	1.1	return;
520			}
521	joko	1.15	php::log(get_class($this) . "->_loadRemote: getObjectByGuid", PEAR_LOG_DEBUG);
522	joko	1.1	$args = array( guid => $this->objectId, classname => $this->meta[classname] );
523	jonen	1.18	$result = $this->backend->send('getObjectByGuid', $args, array( utf8 => 1) );
524	joko	1.1
525			} elseif ($this->meta[oid]) {
526			if (!$this->objectId) {
527	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING);
528	joko	1.1	return;
529			}
530	joko	1.15	php::log(get_class($this) . "->_loadRemote: getObject", PEAR_LOG_DEBUG);
531	jonen	1.18	$result = $this->backend->send('getObject', $this->objectId, array( utf8 => 1) );
532	joko	1.1
533			} elseif ($this->meta[key]) {
534			if (!$this->meta[command]) {
535	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING);
536	joko	1.1	return;
537			}
538			/*
539			if (!$this->meta[query]) {
540	joko	1.15	php::log(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING);
541	joko	1.1	return;
542			}
543			*/
544	joko	1.15	//php::log(get_class($this) . "->_loadRemote: $this->meta[command](" . join(' ', $this->meta[query]) . ")", PEAR_LOG_DEBUG);
545	joko	1.10	//print Dumper(array($this->meta[command], $this->meta[query]));
546	jonen	1.18	$result = $this->backend->send($this->meta[command], $this->meta[query], array( utf8 => 1) );
547	joko	1.1
548			}
549
550	joko	1.10	//print "result: " . dumpVar($result) . "<br>";
551	joko	1.1
552	joko	1.13	$status = $this->backend->status();
553	joko	1.10	//print Dumper($status);
554
555	joko	1.20	$good = !$status[errors] && is_array($result) && sizeof($result) && $status[connected];
556	joko	1.10
557	joko	1.13	if ($good) {
558	joko	1.1
559			// FIXME: this is dangerous!
560	joko	1.13	/*
561	joko	1.1	if ($_GET[debug]) {
562			print Dumper($result);
563			}
564	joko	1.13	*/
565	joko	1.1
566			$this->payload = serialize($result);
567			// ----- move this to _encode some times
568
569			$this->_saveProxy();
570			//print "oid: $this->objectId<br>";
571			$this->flushState();
572	joko	1.10
573	joko	1.1	} else {
574	joko	1.13
575			if (constants::get('APP_MODE_DEBUG')) {
576			$this->draw_error_box($status);
577	joko	1.11	} else {
578	joko	1.13	php::maintenance('rpc', array( status => $status ) );
579	joko	1.11	}
580	joko	1.10
581	joko	1.1	}
582
583			}
584	joko	1.13
585			function draw_error_box($status) {
586			$style = html_style("text/css", '.boxlabel_yellow { color: yellow; font-weight:bold; }');
587			$statusbox = html_div();
588			$statusbox->set_style('background: red; border: 2px black groove; width:640px; padding:10px; margin:40px;');
589			$statusbox->add( html_span('boxlabel_yellow', "Method:"), get_class($this) . "->_loadRemote", html_br() );
590			$statusbox->add( html_span('boxlabel_yellow', "Connected:"), $status[connected], html_br() );
591			$statusbox->add( html_span('boxlabel_yellow', "RPCSESSID:"), $status[RPCSESSID], html_br() );
592			foreach ($status[errors] as $error) {
593	joko	1.14	$msg = html_pre($error[message]);
594			$statusbox->add( html_span('boxlabel_yellow', "Error($error[code]):"), $msg );
595	joko	1.13	}
596	joko	1.1
597	joko	1.13	$message = "Error while talking to remote side. Please check wire, socket or api.";
598	joko	1.15	php::log($message, PEAR_LOG_CRIT);
599	joko	1.13	$statusbox->add( html_span('boxlabel_yellow', "Critical:"), $message, html_br() );
600
601			// V1
602			/*
603			if (constants::get('VERBOSE') \|\| constants::get('ERRORS_ONLY')) {
604			print $style->render();
605			print $statusbox->render();
606			} else {
607			foreach ($status[errors] as $error) {
608			print Dumper($error);
609			}
610			}
611			*/
612
613			// V2
614			trace( container($style, $statusbox) );
615
616			}
617
618
619	joko	1.1	function _saveBackend($result) {
620	joko	1.15	php::log(get_class($this) . "->_saveBackend()");
621	joko	1.1
622			//$encoder = new TextEncode($result);
623			//$encoder->toUTF8();
624
625			// check for guid or oid
626			if($this->meta[guid]) {
627			$args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result );
628			$response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) );
629			}
630			if($this->meta[oid]) {
631			$response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1) );
632			}
633			}
634
635			function _decode() {
636			// fill attributes-hashtable from message-hashtable
637			if (!$this->payload) { return; }
638			//if ($this->attributes = $backend->decodeData($this->payload)) {
639			if ($this->attributes = unserialize($this->payload)) {
640			$this->meta[decoded] = 1;
641			}
642			}
643
644			function store($struct) {
645			$this->payload = serialize($struct);
646			$this->_saveProxy();
647			}
648
649			}
650
651	jonen	1.16	?>
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