| 1 | <?php | 
| 2 |  | 
| 3 | /** | 
| 4 | * This file contains the DesignPattern::Proxy class. | 
| 5 | * | 
| 6 | * @author Andreas Motl <andreas.motl@ilo.de> | 
| 7 | * @module DesignPattern::Proxy | 
| 8 | * | 
| 9 | */ | 
| 10 |  | 
| 11 | /** | 
| 12 | * $Id: MVC.php,v 1.4 2003/03/01 22:44:54 joko Exp $ | 
| 13 | * | 
| 14 | * $Log: MVC.php,v $ | 
| 15 | * | 
| 16 | */ | 
| 17 |  | 
| 18 |  | 
| 19 | /** | 
| 20 | * --- An attempt to implement some software design patterns... | 
| 21 | * --- ProxyPattern | 
| 22 | * | 
| 23 | * --- http://c2.com/cgi-bin/wiki?ProxyPattern | 
| 24 | * | 
| 25 | * @author Andreas Motl <andreas.motl@ilo.de> | 
| 26 | * @copyright (c) 2003 - All Rights reserved. | 
| 27 | * @license GNU LGPL (GNU Lesser General Public License) | 
| 28 | * | 
| 29 | * @author-url http://www.netfrag.org/~joko/ | 
| 30 | * @license-url http://www.gnu.org/licenses/lgpl.txt | 
| 31 | * | 
| 32 | * @package org.netfrag.glib | 
| 33 | * @module DesignPattern::Proxy | 
| 34 | * | 
| 35 | */ | 
| 36 |  | 
| 37 | /** | 
| 38 | * Todo: | 
| 39 | * | 
| 40 | *    x DesignPattern::DecoratorProxy  (->decorate) | 
| 41 | *    x DesignPattern::TransparentProxy  (->make_transparent) | 
| 42 | *    o DesignPattern::MultiProxy   (->both???) (diamond inheritance? possible in php?) | 
| 43 | *    o DesignPattern::GenericAdapterProxy??? | 
| 44 | *      o no 'locator/query' or 'type/component' | 
| 45 | *      o even more generic: just 'adapter_metadata'    (-> global adapter registry?) | 
| 46 |  | 
| 47 |  | 
| 48 | * | 
| 49 | * | 
| 50 | */ | 
| 51 |  | 
| 52 | /** | 
| 53 | * Load required modules: | 
| 54 | * | 
| 55 | */ | 
| 56 | loadModule('Class::Logger'); | 
| 57 |  | 
| 58 | class DesignPattern_Proxy extends Class_Logger { | 
| 59 |  | 
| 60 | /** | 
| 61 | * This holds some information about the tracing level. | 
| 62 | * | 
| 63 | */ | 
| 64 | var $_debug = array( | 
| 65 | notice => 0, | 
| 66 | trace => 0, | 
| 67 | payload => 0, | 
| 68 | ); | 
| 69 |  | 
| 70 | var $_component_name; | 
| 71 | var $_component_options; | 
| 72 |  | 
| 73 | /** | 
| 74 | * This var holds the Handler object | 
| 75 | * that is used to do the work. | 
| 76 | * It acts as a dispatcher combining result caching. | 
| 77 | * It is assumed that this provides 4 methods: | 
| 78 | * queryData() - execute a query against a data storage | 
| 79 | * querySchema() - execute a query against underlying storage metadata | 
| 80 | * sendCommand() - send a command against an arbitrary execution engine | 
| 81 | * ... or others! (these are just proposals for convenience) | 
| 82 | * | 
| 83 | */ | 
| 84 | var $_handler = NULL; | 
| 85 |  | 
| 86 |  | 
| 87 | /** | 
| 88 | * This var holds options fed to the Proxy object | 
| 89 | * These are built from locator metadata (_locator) and query arguments (_query) | 
| 90 | * It's a simple structured hash: | 
| 91 | *  $proxy_options = array( | 
| 92 | *    method => '<remote-method-name>', | 
| 93 | *    args => array('list', 'of', 'arguments') | 
| 94 | *  ); | 
| 95 | * | 
| 96 | */ | 
| 97 | var $_handler_options = NULL; | 
| 98 |  | 
| 99 |  | 
| 100 | function about() { | 
| 101 | $this->_about = | 
| 102 | <<<ABOUT | 
| 103 | * --- DesignPattern::Proxy | 
| 104 | * --- http://cvs.netfrag.org/nfo/php/libs/org.netfrag.glib/DesignPattern/Proxy.php | 
| 105 | * | 
| 106 | *  http://c2.com/cgi-bin/wiki?ProxyPattern says... | 
| 107 | *  Intent: Provide a surrogate or placeholder for another object to control access to it. | 
| 108 | *  http://www.fluffycat.com/java/patterns.html says... | 
| 109 | *  One class controls the creation of and access to objects in another class. | 
| 110 |  | 
| 111 | ABOUT; | 
| 112 | } | 
| 113 |  | 
| 114 |  | 
| 115 | function constructor($handler = array()) { | 
| 116 | if (sizeof($handler)) { | 
| 117 | $this->set_handler($handler); | 
| 118 | } | 
| 119 | $this->create_handler(); | 
| 120 | $this->call_handler(); | 
| 121 | } | 
| 122 |  | 
| 123 | /* | 
| 124 | function _abstract_method($method) { | 
| 125 | $package = get_class($this); | 
| 126 | $package_p = get_parent_class($this); | 
| 127 | user_error("DesignPattern::Proxy.$package_p.$package: Please implement method '$method'."); | 
| 128 | } | 
| 129 | */ | 
| 130 |  | 
| 131 |  | 
| 132 | /** | 
| 133 | * Directly inject a Handler instance to use. | 
| 134 | * | 
| 135 | * @param Handler object - &$handler | 
| 136 | * | 
| 137 | */ | 
| 138 | function set_handler( &$handler ) { | 
| 139 | $this->_handler = &$handler; | 
| 140 | } | 
| 141 |  | 
| 142 | function &get_handler() { | 
| 143 | return $this->_handler; | 
| 144 | } | 
| 145 |  | 
| 146 | function call_handler() { | 
| 147 | $this->_abstract_method('call_handler', 'DesignPattern::Proxy'); | 
| 148 | } | 
| 149 |  | 
| 150 | function set_component_name($name) { | 
| 151 | $this->_component_name = $name; | 
| 152 | } | 
| 153 | function get_component_name() { | 
| 154 | return $this->_component_name; | 
| 155 | } | 
| 156 | function set_component_options($options) { | 
| 157 | $this->_component_options= $options; | 
| 158 | } | 
| 159 | function get_component_options() { | 
| 160 | return $this->_component_options; | 
| 161 | } | 
| 162 |  | 
| 163 | function create_handler() { | 
| 164 | //print "DesignPattern::Proxy->create_handler<br/>"; | 
| 165 | //print "comp: " . $this->get_component_name() . "<br/>"; | 
| 166 | //print "comp: " . $this->get_component_options() . "<br/>"; | 
| 167 | $handler = php::mkComponent( $this->get_component_name(), $this->get_component_options() ); | 
| 168 | //print Dumper($handler); | 
| 169 | //exit; | 
| 170 |  | 
| 171 | $this->set_handler( $handler ); | 
| 172 | } | 
| 173 |  | 
| 174 |  | 
| 175 | } | 
| 176 |  | 
| 177 | ?> |