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<?php |
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/** |
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* This file contains the DesignPattern::RemoteProxy class |
4 |
* |
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* @author Andreas Motl <andreas.motl@ilo.de> |
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* @package org.netfrag.glib |
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* @name DesignPattern::RemoteProxy |
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* |
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* |
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*/ |
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|
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|
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/** |
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* <b>Cvs-Log:</b> |
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* |
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* <pre> |
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* ------------------------------------------------------------------------- |
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* $Id: RemoteProxy.php,v 1.8 2003/03/10 22:31:56 joko Exp $ |
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* ------------------------------------------------------------------------- |
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* $Log: RemoteProxy.php,v $ |
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* Revision 1.8 2003/03/10 22:31:56 joko |
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* + fixed metadata for phpDocumentor |
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* |
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* Revision 1.7 2003/03/09 15:51:44 joko |
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* + additional metadata for Autodia |
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* |
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* Revision 1.6 2003/03/05 17:28:43 joko |
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* updated docu (phpDocumentor testing....) |
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* |
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* Revision 1.5 2003/03/05 17:02:22 joko |
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* updated docu (phpDocumentor testing....) |
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* |
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* Revision 1.4 2003/03/05 16:32:19 joko |
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* updated docu (phpDocumentor testing....) |
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* |
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* Revision 1.3 2003/03/05 16:10:17 joko |
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* updated docu (phpDocumentor testing....) |
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* |
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* Revision 1.2 2003/03/05 12:14:02 joko |
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* renamed method |
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* constructor argument expansion |
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* |
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* Revision 1.1 2003/03/03 22:06:46 joko |
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* refactored from Data::Driver::Proxy |
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* |
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* Revision 1.3 2003/03/01 04:56:38 joko |
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* new comment style for large blocks - stolen from phpHtmlLib |
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* commit-log encapsulated into such a block |
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* introduced some documentation |
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* refactored todo (now also inside a stylish block) |
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* |
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* Revision 1.2 2003/02/13 21:48:09 joko |
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* + caching mechanisms more configurable now |
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* |
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* Revision 1.1 2003/02/09 17:23:21 joko |
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* + refactored from flib/Application/RPC/ProxyObject.php |
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* |
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* Revision 1.7 2003/02/03 03:31:38 jonen |
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* - moved '$encoder->toISO()' to 'Remote.php' |
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* |
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* Revision 1.6 2002/12/22 13:26:20 jonen |
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* + added support of tangram independent id (e.g. Data::UUID) toggled by option at conrtuctor |
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* |
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* Revision 1.5 2002/12/18 22:36:49 jonen |
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* + added support to get remote objects via backend via 'guid' |
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* + renamed '_loadBackend' to '_loadRemote' |
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* + constructor now accepts additional options: |
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* + remote: try to get object via '_loadRemote' ... |
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* + oid: use the given identifier as an 'oid' when doing '_loadRemote' |
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* + guid: use the given identifier as a 'guid' when doing '_loadRemote' |
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* |
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* Revision 1.4 2002/12/12 02:46:31 joko |
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* + state (session) gets flushed when data was successfully loaded from remote side |
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* + fixed _loadBackend |
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* + fixed flushState |
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* |
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* Revision 1.3 2002/12/06 04:12:54 joko |
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* + replaced 'xyzCache' through 'xyzProxy' |
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* + function store(...) |
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* |
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* Revision 1.2 2002/12/05 21:44:09 joko |
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* + debugging |
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* |
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* Revision 1.1 2002/12/01 17:23:58 joko |
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* + initial check-in |
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* |
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* Revision 1.11 2002/11/12 06:05:58 cvsjoko |
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* + renamed class: Text_Encode -> TextEncode |
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* |
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* Revision 1.10 2002/10/29 19:15:33 cvsjoko |
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* - moved utf8/iso-conversion to lib/utils/Text_Encode.php |
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* |
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* Revision 1.9 2002/10/26 12:32:36 cvsjoko |
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* - removed debugging via "print" |
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* + added generic logging via PEAR::Log |
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* |
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* Revision 1.8 2002/10/22 09:51:38 cvsmax |
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* + moved semi-method 'createBackend' to method $site->user->create at User.class.php |
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* |
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* Revision 1.7 2002/10/21 18:27:09 cvsjoko |
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* - manually disabled any form of caching |
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* |
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* Revision 1.6 2002/10/17 03:48:47 cvsmax |
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* + new |
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* + function _createBackend create new Backend |
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* + function _create api-create |
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* |
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* Revision 1.5 2002/10/16 03:37:54 cvsjoko |
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* + bugfix: wrong comparison in restriction to save to array |
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* |
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* Revision 1.4 2002/10/10 03:04:23 cvsjoko |
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* + no debug-output |
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* |
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* Revision 1.3 2002/10/10 03:03:27 cvsjoko |
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* + bugfix: save object to cache only if payload from backend isn't empty |
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* |
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* Revision 1.2 2002/10/10 02:40:06 cvsjoko |
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* + new level of data-caching (session and persistant) |
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* + function _loadState loads data from session |
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* + function _saveState saves data to session |
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* + function save api-save (session & backend) |
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* + function _commit saves data to backend |
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* + handy utils |
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* + function _setAttributes |
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* + function flushState |
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* |
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* Revision 1.1 2002/10/09 00:51:39 cvsjoko |
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* + new |
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* ------------------------------------------------------------------------- |
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* </pre> |
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* |
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*/ |
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|
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|
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|
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|
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/** |
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* Load required modules: |
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* |
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*/ |
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loadModule('DesignPattern::Proxy'); |
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|
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|
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/** |
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* DesignPattern::RemoteProxy -- Multiple stage data fetching and caching |
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* |
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* |
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* This class (DesignPattern::RemoteProxy) provides an abstract framework |
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* for loading/saving arbitrary data from/to data storages interfaced |
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* by storage *proxy*-drivers. |
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* Don't mix these up with the concrete storage *handle*-drivers |
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* doing the lowlevel stuff (opening files, talking sql, etc.). |
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* These proxy-drivers are "just" wrappers around them |
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* providing a more highlevel, consistent API making |
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* it easier for Data::Driver::Proxy to do its main work: |
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* |
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* quote from: http://home.earthlink.net/~huston2/dp/proxy.html |
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* "A remote proxy provides a local representative for an |
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* object that resides in a different address space. This is |
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* what the "stub" code in RPC and CORBA provides." |
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* |
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* |
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* Multiple stage data fetching and caching: |
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* |
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* <pre> |
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* |
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* DATA, ... |
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* ... also refered to as data, should be handled as |
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* something called data. |
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* |
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* STAGES |
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* x native php4 session: serialized payload |
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* x single rdbms table: serialized payload |
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* x ... via custom database wrapper |
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* x included php-file, included php-library |
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* o object, component, package, callbacks |
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* x ... via php PEAR DB abstraction objects |
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* x remote objects (items): flat attribute hash |
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* o use Data::Object::Identity |
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* o via Data::Driver::Proxy::RPC or others |
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* o Data::Object::Encoder: encodes/decodes values |
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* o Data::Object::Interpolator: interpolates/resolves references |
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* |
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* WORK |
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* x move data transparently around between these stages |
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* |
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* TOOLS |
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* |
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* x Overview - Packages, Handlers and Stages: |
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* This is weird. ;-) |
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* - A Package can be instantiated by its namespaced classname |
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* e.g.: "mkObject('My::Package');" |
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* - A Package can be a Handler for Data::Driver::Proxy |
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* - A Handler implements exactly one Stage |
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* - Data::Driver::Proxy itself embeds these Stages: |
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* x php4-session |
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* x rdbms-table |
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* - An example Handler is Data::Driver::RPC::Remote |
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* |
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* x Handlers: |
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* x Data::Driver::RPC::Remote |
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* Interacts with a RPC::XML server (todo: talk SOAP!) |
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* using PEAR::XML::RPC. |
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* It can cache data for "disconnected mode" using the |
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* o Data::Driver::phpHtmlLib |
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* o Data::Driver::PEAR::DB |
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* x Data::Driver::PEAR::Tree (via Data::Lift) |
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* |
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* </pre> |
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* |
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* |
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* An attempt to implement some software design patterns |
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* --- RemoteProxyPattern |
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* |
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* @link http://www.agcs.com/supportv2/techpapers/patterns/papers/tutnotes/sld017.htm |
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* @link http://home.earthlink.net/~huston2/dp/proxy.html |
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* @link http://wiki.cs.uiuc.edu/PatternStories/RemoteObject |
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* @link http://c2.com/cgi-bin/wiki?ProxyPattern |
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* @link http://c2.com/cgi-bin/wiki?LazyProxies |
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* |
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* @author Andreas Motl <andreas.motl@ilo.de> |
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* @link http://www.netfrag.org/~joko/ |
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* |
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* @copyright (c) 2003 - All Rights reserved. |
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* @license GNU LGPL (GNU Lesser General Public License) |
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* @link http://www.gnu.org/licenses/lgpl.txt |
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* |
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* @package org.netfrag.glib |
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* @subpackage DesignPattern |
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* @name DesignPattern::RemoteProxy |
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* |
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* |
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* @todo extend options to en-/disable caching via a) session and/or b) database |
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* make feature available via runtime setter-method to these options |
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* @todo PEAR::Cache for caching purposes!!! |
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* @todo refactor database access: use PEAR for this! no more 'connectdb' here!!! |
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* @todo make database connection more flexible to make possible |
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* to have different (probably named) proxy databases (besides a "main database") |
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* @todo rename this to Data::Proxy? or split into Data::Query, Data::Result and Data::Wrapper? |
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* @todo refactor this to a "RemoteObject" class!!! (inheriting from DesignPattern::RemoteObject) |
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* @todo rename this to "DesignPattern::LazyRemoteProxy"??? |
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* |
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*/ |
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class DesignPattern_RemoteProxy extends DesignPattern_Proxy { |
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|
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var $objectId; |
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// purpose ... |
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var $meta; |
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var $payload; |
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var $attributes; |
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var $backend; |
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|
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function DesignPattern_RemoteProxy($objectId = "", $options = array() ) { |
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logp(get_class($this) . "->new()", PEAR_LOG_INFO); |
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global $proxy; |
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|
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// 2003-03-05 - modified constructor |
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// expand objectId |
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if (is_array($objectId)) { |
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$options = $objectId[1]; |
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$objectId = $objectId[0]; |
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} |
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|
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// trace |
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//print Dumper($objectId, $options); |
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|
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// initialization/startup |
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$this->_init_meta_options($objectId, $options); |
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$this->_init_caching(); |
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$this->_init_load(); |
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|
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//print Dumper($this); |
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|
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} |
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|
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function _init_meta_options( $objectId="", $options = array() ) { |
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$this->meta = $options; |
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|
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if ($objectId) { |
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$this->objectId = $objectId; |
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|
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// set default load mechanism |
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if ( $this->meta[remote] && ((!$this->meta[oid] && !$this->meta[guid]) || ($this->meta[oid] && $this->meta[guid])) && (!$this->meta[key]) ) { |
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$this->meta[oid] = 1; |
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} |
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|
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} |
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} |
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|
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function _init_caching() { |
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|
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if ($this->meta[cache][session]) { |
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session_register_safe("proxy"); |
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} |
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|
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/** |
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* <!-- Autodia --> |
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* can do: (this is metadata supplied for Autodia, don't delete!) |
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* $this->backend = new DataSource_Proxy_XMLRPC() |
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* |
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*/ |
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|
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if ($this->meta[remote]) { |
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//$this->backend = mkObject('Data::Driver::RPC::Remote', $this->meta[rpcinfo]); |
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$this->backend = php::mkComponent('DataSource::Proxy::XMLRPC', $this->meta[rpcinfo]); |
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} |
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} |
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|
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function _init_load() { |
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if ($this->objectId) { |
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$this->load(); |
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//$this->_saveProxy(); |
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} |
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} |
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|
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|
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function load() { |
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logp(get_class($this) . "->load()", PEAR_LOG_INFO); |
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if (!$this->_loadState()) { |
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if (!$this->_loadProxy()) { |
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|
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// just load object from remote side if its flagged to be a remote one ... |
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if ($this->meta[remote]) { |
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$this->_loadRemote(); |
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} |
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|
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} |
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} |
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} |
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|
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function save($data, $type) { |
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$this->_setAttributes($data); |
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$this->_saveState(); |
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if ($type == 'commit') { |
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$this->_commit(); |
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} |
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if ($type == 'create') { |
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$this->_create(); |
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} |
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} |
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|
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function flush() { |
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$this->flushState(); |
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$this->flushProxy(); |
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} |
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|
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function _commit() { |
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$this->_saveBackend($this->attributes); |
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$this->flushState(); |
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$this->flushProxy(); |
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} |
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|
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|
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// TODO: make this work |
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/* |
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function _create() { |
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$this->_createBackend($this->attributes); |
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$this->flushState(); |
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$this->flushProxy(); |
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} |
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*/ |
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|
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function getResult() { |
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if (!$this->meta[decoded]) { |
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$this->_decode(); |
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$this->_saveState(); |
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} |
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return $this->attributes; |
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} |
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|
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function _setAttributes($data) { |
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$this->attributes = $data; |
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} |
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|
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function flushProxy() { |
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connectdb(); |
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$sql = "DELETE FROM f_proxy WHERE oid='$this->objectId'"; |
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send_sql($sql); |
379 |
} |
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|
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function flushState() { |
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global $proxy; |
383 |
unset($proxy[$this->objectId]); |
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$this->meta[decoded] = 0; |
385 |
} |
386 |
|
387 |
function _loadState() { |
388 |
global $proxy; |
389 |
|
390 |
// trace |
391 |
//print Dumper($this); |
392 |
|
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// debug |
394 |
logp(get_class($this) . "->_loadState()"); |
395 |
|
396 |
if ($this->attributes = $proxy[$this->objectId]) { |
397 |
//print "_loadState:" . dumpVar($this->attributes); |
398 |
$this->meta[decoded] = 1; |
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// TODO: make a parameter from this (0 deactivates session-layer) |
400 |
return 0; |
401 |
} |
402 |
} |
403 |
|
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function _saveState() { |
405 |
global $proxy; |
406 |
logp(get_class($this) . "->_saveState()"); |
407 |
$proxy[$this->objectId] = $this->attributes; |
408 |
//print "_saveState: " . dumpVar($this->attributes); |
409 |
// TODO: throw exception-message back to user if operation fails |
410 |
} |
411 |
|
412 |
function _loadProxy() { |
413 |
|
414 |
// FIXME! |
415 |
if (!$this->meta[cache][db]) { return; } |
416 |
|
417 |
// trace & debug |
418 |
//print Dumper($this); |
419 |
logp(get_class($this) . "->_loadProxy()"); |
420 |
|
421 |
connectdb(); |
422 |
$sql = "SELECT payload FROM f_proxy WHERE oid='$this->objectId'"; |
423 |
if ($res = send_sql($sql)) { |
424 |
$row = mysql_fetch_array($res, MYSQL_ASSOC); |
425 |
if ($row) { |
426 |
$this->payload = $row[payload]; |
427 |
// TODO: make a parameter from this (0 deactivates mysqldb-layer) |
428 |
return 0; |
429 |
} |
430 |
} |
431 |
} |
432 |
|
433 |
// TODO: use PEAR here |
434 |
function _saveProxy() { |
435 |
|
436 |
// FIXME! |
437 |
if (!$this->meta[cache][db]) { return; } |
438 |
|
439 |
logp(get_class($this) . "->_saveProxy()"); |
440 |
connectdb(); |
441 |
if ($this->payload) { |
442 |
//$sql = "INSERT INTO f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'"; |
443 |
$sql = "INSERT INTO f_proxy SET oid='$this->objectId', payload='$this->payload'"; |
444 |
if (!send_sql($sql)) { |
445 |
$sql = "UPDATE f_proxy SET payload='$this->payload' WHERE oid='$this->objectId'"; |
446 |
send_sql($sql); |
447 |
} |
448 |
} |
449 |
} |
450 |
|
451 |
function _loadRemote() { |
452 |
logp(get_class($this) . "->_loadRemote()"); |
453 |
|
454 |
// trace |
455 |
//print Dumper($this->meta); |
456 |
|
457 |
// TODO: test backend for reachability first (eventually cache this information and "reset" it by another party) |
458 |
|
459 |
// 1. check backend-handle |
460 |
if (!$this->backend) { |
461 |
logp(get_class($this) . "->_loadRemote: no backend handle, please check argument 'rpcinfo'", PEAR_LOG_CRIT); |
462 |
return; |
463 |
} |
464 |
|
465 |
// determine backend action by metadata |
466 |
// check for guid or oid |
467 |
if ($this->meta[guid]) { |
468 |
if (!$this->objectId) { |
469 |
logp(get_class($this) . "->_loadRemote: argument 'guid' requires valid objectId", PEAR_LOG_WARNING); |
470 |
return; |
471 |
} |
472 |
if (!$this->meta[classname]) { |
473 |
logp(get_class($this) . "->_loadRemote: argument 'guid' requires 'classname'", PEAR_LOG_WARNING); |
474 |
return; |
475 |
} |
476 |
$args = array( guid => $this->objectId, classname => $this->meta[classname] ); |
477 |
$result = $this->backend->send('getObjectByGuid', $args ); |
478 |
|
479 |
} elseif ($this->meta[oid]) { |
480 |
if (!$this->objectId) { |
481 |
logp(get_class($this) . "->_loadRemote: argument 'oid' requires valid objectId", PEAR_LOG_WARNING); |
482 |
return; |
483 |
} |
484 |
$result = $this->backend->send('getObject', $this->objectId); |
485 |
|
486 |
} elseif ($this->meta[key]) { |
487 |
if (!$this->meta[command]) { |
488 |
logp(get_class($this) . "->_loadRemote: argument 'key' requires 'command'", PEAR_LOG_WARNING); |
489 |
return; |
490 |
} |
491 |
/* |
492 |
if (!$this->meta[query]) { |
493 |
logp(get_class($this) . "->_loadRemote: argument 'key' requires 'query'", PEAR_LOG_WARNING); |
494 |
return; |
495 |
} |
496 |
*/ |
497 |
$result = $this->backend->send($this->meta[command], $this->meta[query]); |
498 |
|
499 |
} |
500 |
|
501 |
|
502 |
|
503 |
if ($result) { |
504 |
//print "result: " . dumpVar($result) . "<br>"; |
505 |
if (count($result) == 0) { return; } |
506 |
|
507 |
// FIXME: this is dangerous! |
508 |
if ($_GET[debug]) { |
509 |
print Dumper($result); |
510 |
} |
511 |
|
512 |
$this->payload = serialize($result); |
513 |
// ----- move this to _encode some times |
514 |
|
515 |
$this->_saveProxy(); |
516 |
//print "oid: $this->objectId<br>"; |
517 |
$this->flushState(); |
518 |
} else { |
519 |
//print "Error in _loadRemote!!!<br>"; |
520 |
logp(get_class($this) . "->_loadRemote: error while trying to talk to remote side", PEAR_LOG_CRIT); |
521 |
} |
522 |
|
523 |
} |
524 |
|
525 |
function _saveBackend($result) { |
526 |
logp(get_class($this) . "->_saveBackend()"); |
527 |
|
528 |
//$encoder = new TextEncode($result); |
529 |
//$encoder->toUTF8(); |
530 |
|
531 |
// check for guid or oid |
532 |
if($this->meta[guid]) { |
533 |
$args = array( 'guid' => $this->objectId, 'classname' => $this->meta[classname], 'data' => $result ); |
534 |
$response = $this->backend->send('saveObjectByGuid', $args, array( utf8 => 1) ); |
535 |
} |
536 |
if($this->meta[oid]) { |
537 |
$response = $this->backend->send('saveObject', array('oid' => $this->objectId, 'data' => $result), array( utf8 => 1) ); |
538 |
} |
539 |
} |
540 |
|
541 |
function _decode() { |
542 |
// fill attributes-hashtable from message-hashtable |
543 |
if (!$this->payload) { return; } |
544 |
//if ($this->attributes = $backend->decodeData($this->payload)) { |
545 |
if ($this->attributes = unserialize($this->payload)) { |
546 |
$this->meta[decoded] = 1; |
547 |
} |
548 |
} |
549 |
|
550 |
function store($struct) { |
551 |
$this->payload = serialize($struct); |
552 |
$this->_saveProxy(); |
553 |
} |
554 |
|
555 |
} |
556 |
|
557 |
?> |