1 | <?php |
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2 | // +-----------------------------------------------------------------------+ |
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3 | // | Piwigo - a PHP based photo gallery | |
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4 | // +-----------------------------------------------------------------------+ |
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5 | // | Copyright(C) 2008-2012 Piwigo Team http://piwigo.org | |
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6 | // | Copyright(C) 2003-2008 PhpWebGallery Team http://phpwebgallery.net | |
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7 | // | Copyright(C) 2002-2003 Pierrick LE GALL http://le-gall.net/pierrick | |
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8 | // +-----------------------------------------------------------------------+ |
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9 | // | This program is free software; you can redistribute it and/or modify | |
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10 | // | it under the terms of the GNU General Public License as published by | |
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11 | // | the Free Software Foundation | |
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12 | // | | |
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13 | // | This program is distributed in the hope that it will be useful, but | |
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14 | // | WITHOUT ANY WARRANTY; without even the implied warranty of | |
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15 | // | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
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16 | // | General Public License for more details. | |
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17 | // | | |
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18 | // | You should have received a copy of the GNU General Public License | |
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19 | // | along with this program; if not, write to the Free Software | |
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20 | // | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, | |
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21 | // | USA. | |
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22 | // +-----------------------------------------------------------------------+ |
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23 | |
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24 | /* |
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25 | Events and event handlers are the core of Piwigo plugin management. |
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26 | Plugins are addons that are found in plugins subdirectory. If activated, PWG |
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27 | will include the index.php of each plugin. |
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28 | Events are triggered by PWG core code. Plugins (or even PWG itself) can |
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29 | register their functions to handle these events. An event is identified by a |
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30 | string. |
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31 | */ |
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32 | |
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33 | define('PHPWG_PLUGINS_PATH', PHPWG_ROOT_PATH.'plugins/'); |
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34 | |
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35 | define('EVENT_HANDLER_PRIORITY_NEUTRAL', 50); |
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36 | |
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37 | /* Register a event handler. |
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38 | * @param string $event the name of the event to listen to |
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39 | * @param mixed $func the function that will handle the event |
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40 | * @param int $priority optional priority (greater priority will |
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41 | * be executed at last) |
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42 | */ |
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43 | function add_event_handler($event, $func, |
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44 | $priority=EVENT_HANDLER_PRIORITY_NEUTRAL, $accepted_args=1) |
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45 | { |
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46 | global $pwg_event_handlers; |
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47 | |
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48 | if ( isset($pwg_event_handlers[$event][$priority]) ) |
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49 | { |
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50 | foreach($pwg_event_handlers[$event][$priority] as $handler) |
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51 | { |
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52 | if ( $handler['function'] == $func ) |
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53 | { |
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54 | return false; |
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55 | } |
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56 | } |
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57 | } |
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58 | |
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59 | $pwg_event_handlers[$event][$priority][] = |
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60 | array( |
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61 | 'function'=>$func, |
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62 | 'accepted_args'=>$accepted_args); |
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63 | ksort( $pwg_event_handlers[$event] ); |
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64 | return true; |
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65 | } |
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66 | |
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67 | /* Register a event handler. |
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68 | * @param string $event the name of the event to listen to |
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69 | * @param mixed $func the function that needs removal |
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70 | * @param int $priority optional priority (greater priority will |
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71 | * be executed at last) |
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72 | */ |
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73 | function remove_event_handler($event, $func, |
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74 | $priority=EVENT_HANDLER_PRIORITY_NEUTRAL) |
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75 | { |
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76 | global $pwg_event_handlers; |
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77 | |
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78 | if (!isset( $pwg_event_handlers[$event][$priority] ) ) |
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79 | { |
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80 | return false; |
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81 | } |
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82 | for ($i=0; $i<count($pwg_event_handlers[$event][$priority]); $i++) |
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83 | { |
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84 | if ($pwg_event_handlers[$event][$priority][$i]['function']==$func) |
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85 | { |
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86 | unset($pwg_event_handlers[$event][$priority][$i]); |
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87 | $pwg_event_handlers[$event][$priority] = |
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88 | array_values($pwg_event_handlers[$event][$priority]); |
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89 | |
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90 | if ( empty($pwg_event_handlers[$event][$priority]) ) |
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91 | { |
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92 | unset( $pwg_event_handlers[$event][$priority] ); |
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93 | if (empty( $pwg_event_handlers[$event] ) ) |
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94 | { |
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95 | unset( $pwg_event_handlers[$event] ); |
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96 | } |
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97 | } |
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98 | return true; |
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99 | } |
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100 | } |
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101 | return false; |
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102 | } |
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103 | |
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104 | /* Triggers an event and calls all registered event handlers |
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105 | * @param string $event name of the event |
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106 | * @param mixed $data data to pass to handlers |
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107 | */ |
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108 | function trigger_event($event, $data=null) |
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109 | { |
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110 | global $pwg_event_handlers; |
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111 | |
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112 | if ( isset($pwg_event_handlers['trigger']) ) |
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113 | {// just for debugging |
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114 | trigger_action('trigger', |
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115 | array('type'=>'event', 'event'=>$event, 'data'=>$data) ); |
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116 | } |
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117 | |
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118 | if ( !isset($pwg_event_handlers[$event]) ) |
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119 | { |
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120 | return $data; |
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121 | } |
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122 | $args = func_get_args(); |
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123 | |
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124 | foreach ($pwg_event_handlers[$event] as $priority => $handlers) |
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125 | { |
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126 | foreach($handlers as $handler) |
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127 | { |
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128 | $function_name = $handler['function']; |
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129 | $accepted_args = $handler['accepted_args']; |
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130 | $args[1] = $data; |
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131 | $data = call_user_func_array($function_name, array_slice($args,1,$accepted_args) ); |
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132 | } |
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133 | } |
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134 | trigger_action('trigger', |
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135 | array('type'=>'post_event', 'event'=>$event, 'data'=>$data) ); |
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136 | return $data; |
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137 | } |
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138 | |
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139 | function trigger_action($event, $data=null) |
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140 | { |
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141 | global $pwg_event_handlers; |
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142 | if ( isset($pwg_event_handlers['trigger']) and $event!='trigger' ) |
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143 | {// special case for debugging - avoid recursive calls |
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144 | trigger_action('trigger', |
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145 | array('type'=>'action', 'event'=>$event, 'data'=>$data) ); |
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146 | } |
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147 | |
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148 | if ( !isset($pwg_event_handlers[$event]) ) |
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149 | { |
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150 | return; |
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151 | } |
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152 | $args = func_get_args(); |
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153 | |
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154 | foreach ($pwg_event_handlers[$event] as $priority => $handlers) |
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155 | { |
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156 | foreach($handlers as $handler) |
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157 | { |
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158 | $function_name = $handler['function']; |
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159 | $accepted_args = $handler['accepted_args']; |
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160 | |
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161 | call_user_func_array($function_name, array_slice($args,1,$accepted_args) ); |
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162 | } |
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163 | } |
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164 | } |
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165 | |
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166 | /** Saves some data with the associated plugim id. It can be retrieved later ( |
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167 | * during this script lifetime) using get_plugin_data |
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168 | * @param string plugin_id |
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169 | * @param mixed data |
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170 | * returns true on success, false otherwise |
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171 | */ |
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172 | function set_plugin_data($plugin_id, &$data) |
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173 | { |
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174 | global $pwg_loaded_plugins; |
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175 | if ( isset($pwg_loaded_plugins[$plugin_id]) ) |
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176 | { |
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177 | $pwg_loaded_plugins[$plugin_id]['plugin_data'] = &$data; |
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178 | return true; |
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179 | } |
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180 | return false; |
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181 | } |
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182 | |
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183 | /** Retrieves plugin data saved previously with set_plugin_data |
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184 | * @param string plugin_id |
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185 | */ |
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186 | function &get_plugin_data($plugin_id) |
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187 | { |
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188 | global $pwg_loaded_plugins; |
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189 | if ( isset($pwg_loaded_plugins[$plugin_id]) ) |
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190 | { |
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191 | return $pwg_loaded_plugins[$plugin_id]['plugin_data']; |
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192 | } |
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193 | return null; |
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194 | } |
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195 | |
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196 | /* Returns an array of plugins defined in the database |
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197 | * @param string $state optional filter on this state |
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198 | * @param string $id optional returns only data about given plugin |
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199 | */ |
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200 | function get_db_plugins($state='', $id='') |
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201 | { |
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202 | $query = ' |
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203 | SELECT * FROM '.PLUGINS_TABLE; |
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204 | $clauses = array(); |
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205 | if (!empty($state)) |
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206 | { |
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207 | $clauses[] = 'state=\''.$state.'\''; |
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208 | } |
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209 | if (!empty($id)) |
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210 | { |
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211 | $clauses[] = 'id="'.$id.'"'; |
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212 | } |
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213 | if (count($clauses)) |
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214 | { |
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215 | $query .= ' |
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216 | WHERE '. implode(' AND ', $clauses); |
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217 | } |
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218 | |
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219 | $result = pwg_query($query); |
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220 | $plugins = array(); |
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221 | while ($row = pwg_db_fetch_assoc($result)) |
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222 | { |
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223 | array_push($plugins, $row); |
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224 | } |
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225 | return $plugins; |
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226 | } |
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227 | |
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228 | |
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229 | function load_plugin($plugin) |
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230 | { |
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231 | $file_name = PHPWG_PLUGINS_PATH.$plugin['id'].'/main.inc.php'; |
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232 | if ( file_exists($file_name) ) |
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233 | { |
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234 | global $pwg_loaded_plugins; |
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235 | $pwg_loaded_plugins[ $plugin['id'] ] = $plugin; |
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236 | include_once( $file_name ); |
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237 | } |
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238 | } |
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239 | |
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240 | /*loads all the plugins on startup*/ |
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241 | function load_plugins() |
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242 | { |
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243 | global $conf, $pwg_loaded_plugins; |
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244 | $pwg_loaded_plugins = array(); |
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245 | if ($conf['enable_plugins']) |
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246 | { |
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247 | $plugins = get_db_plugins('active'); |
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248 | foreach( $plugins as $plugin) |
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249 | {// include main from a function to avoid using same function context |
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250 | load_plugin($plugin); |
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251 | } |
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252 | trigger_action('plugins_loaded'); |
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253 | } |
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254 | } |
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255 | ?> |
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