* (bug 10181) Support the XCache object caching mechanism [patch from Kurt Radwanski]
[lhc/web/wiklou.git] / includes / api / ApiBase.php
index fb9395e..723a679 100644 (file)
-<?php\r
-\r
-\r
-/*\r
- * Created on Sep 5, 2006\r
- *\r
- * API for MediaWiki 1.8+\r
- *\r
- * Copyright (C) 2006 Yuri Astrakhan <FirstnameLastname@gmail.com>\r
- *\r
- * This program is free software; you can redistribute it and/or modify\r
- * it under the terms of the GNU General Public License as published by\r
- * the Free Software Foundation; either version 2 of the License, or\r
- * (at your option) any later version.\r
- *\r
- * This program is distributed in the hope that it will be useful,\r
- * but WITHOUT ANY WARRANTY; without even the implied warranty of\r
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\r
- * GNU General Public License for more details.\r
- *\r
- * You should have received a copy of the GNU General Public License along\r
- * with this program; if not, write to the Free Software Foundation, Inc.,\r
- * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.\r
- * http://www.gnu.org/copyleft/gpl.html\r
- */\r
-\r
-// Multi-valued enums, limit the values user can supply for the parameter\r
-define('GN_ENUM_DFLT', 0);\r
-define('GN_ENUM_ISMULTI', 1);\r
-define('GN_ENUM_CHOICES', 2);\r
-\r
-abstract class ApiBase {\r
-\r
-       private $mMainModule;\r
-\r
-       /**\r
-       * Constructor\r
-       */\r
-       public function __construct($mainModule) {\r
-               $this->mMainModule = $mainModule;\r
-       }\r
-\r
-       /**\r
-        * Executes this module\r
-        */\r
-       abstract function Execute();\r
-\r
-       /**\r
-        * Get main module\r
-        */\r
-       public function GetMain() {\r
-               return $this->mMainModule;\r
-       }\r
-\r
-       /**\r
-        * If this module's $this is the same as $this->mMainModule, its the root, otherwise no\r
-        */\r
-       public function IsMain() {\r
-               return $this === $this->mMainModule;\r
-       }\r
-\r
-       /**\r
-        * Get result object\r
-        */\r
-       public function GetResult() {\r
-               // Main module has GetResult() method overriden\r
-               // Safety - avoid infinite loop:\r
-               if ($this->IsMain())\r
-                       $this->DieDebug(__METHOD__ .\r
-                       ' base method was called on main module. ');\r
-               return $this->GetMain()->GetResult();\r
-       }\r
-\r
-       /**\r
-        * Generates help message for this module, or false if there is no description\r
-        */\r
-       public function MakeHelpMsg() {\r
-\r
-               $msg = $this->GetDescription();\r
-\r
-               if ($msg !== false) {\r
-\r
-                       if (is_array($msg))\r
-                               $msg = implode("\n", $msg);\r
-                       $msg .= "\n";\r
-\r
-                       // Parameters\r
-                       $params = $this->GetAllowedParams();\r
-                       if ($params !== false) {\r
-                               $paramsDescription = $this->GetParamDescription();\r
-                               $msg .= "Supported Parameters:\n";\r
-                               foreach (array_keys($params) as $paramName) {\r
-                                       $desc = isset ($paramsDescription[$paramName]) ? $paramsDescription[$paramName] : '';\r
-                                       $msg .= sprintf("  %-14s - %s\n", $paramName, $desc);\r
-                               }\r
-                       }\r
-\r
-                       // Examples\r
-                       $examples = $this->GetExamples();\r
-                       if ($examples !== false) {\r
-                               if (is_array($examples)) {\r
-                                       $msg .= "Examples:\n";\r
-                                       $msg .= implode("\n  ", $examples) . "\n";\r
-                               } else {\r
-                                       $msg .= "Example:   $examples\n";\r
-                               }\r
-                       }\r
-               }\r
-\r
-               return $msg;\r
-       }\r
-\r
-       /**\r
-        * Returns the description string for this module\r
-        */\r
-       protected function GetDescription() {\r
-               return false;\r
-       }\r
-\r
-       /**\r
-        * Returns usage examples for this module. Return null if no examples are available.\r
-        */\r
-       protected function GetExamples() {\r
-               return false;\r
-       }\r
-\r
-       /**\r
-        * Returns an array of allowed parameters (keys) => default value for that parameter\r
-        */\r
-       protected function GetAllowedParams() {\r
-               return false;\r
-       }\r
-\r
-       /**\r
-        * Returns the description string for the given parameter.\r
-        */\r
-       protected function GetParamDescription() {\r
-               return false;\r
-       }\r
-\r
-       /**\r
-       * Using GetAllowedParams(), makes an array of the values provided by the user,\r
-       * with key being the name of the variable, and value - validated value from user or default.\r
-       * This method can be used to generate local variables using extract().\r
-       */\r
-       public function ExtractRequestParams() {\r
-               global $wgRequest;\r
-\r
-               $params = $this->GetAllowedParams();\r
-               $results = array ();\r
-\r
-               foreach ($params as $param => $dflt) {\r
-                       switch (gettype($dflt)) {\r
-                               case 'NULL' :\r
-                               case 'string' :\r
-                                       $result = $wgRequest->getVal($param, $dflt);\r
-                                       break;\r
-                               case 'integer' :\r
-                                       $result = $wgRequest->getInt($param, $dflt);\r
-                                       break;\r
-                               case 'boolean' :\r
-                                       // Having a default value of 'true' is pointless\r
-                                       $result = $wgRequest->getCheck($param);\r
-                                       break;\r
-                               case 'array' :\r
-                                       $enumParams = $dflt;\r
-                                       $dflt = isset ($enumParams[GN_ENUM_DFLT]) ? $enumParams[GN_ENUM_DFLT] : null;\r
-                                       $multi = isset ($enumParams[GN_ENUM_ISMULTI]) ? $enumParams[GN_ENUM_ISMULTI] : false;\r
-                                       $choices = isset ($enumParams[GN_ENUM_CHOICES]) ? $enumParams[GN_ENUM_CHOICES] : null;\r
-                                       $value = $wgRequest->getVal($param, $dflt);\r
-                                       $result = $this->ParseMultiValue($param, $value, $multi, $choices);\r
-                                       break;\r
-                               default :\r
-                                       $this->DieDebug("In '$param', unprocessed type " . gettype($dflt));\r
-                       }\r
-                       $results[$param] = $result;\r
-               }\r
-\r
-               return $results;\r
-       }\r
-\r
-       /**\r
-       * Return an array of values that were given in a "a|b|c" notation,\r
-       * after it optionally validates them against the list allowed values.\r
-       * \r
-       * @param valueName - The name of the parameter (for error reporting)\r
-       * @param value - The value being parsed\r
-       * @param allowMultiple - Can $value contain more than one value separated by '|'?\r
-       * @param allowedValues - An array of values to check against. If null, all values are accepted.\r
-       * @return (allowMultiple ? an_array_of_values : a_single_value) \r
-       */\r
-       protected function ParseMultiValue($valueName, $value, $allowMultiple, $allowedValues) {\r
-               $valuesList = explode('|', $value);\r
-               if (!$allowMultiple && count($valuesList) != 1) {\r
-                       $possibleValues = is_array($allowedValues) ? "of '" . implode("', '", $allowedValues) . "'" : '';\r
-                       $this->DieUsage("Only one $possibleValues is allowed for parameter '$valueName'", "multival_$valueName");\r
-               }\r
-               if (is_array($allowedValues)) {\r
-                       $unknownValues = array_diff($valuesList, $allowedValues);\r
-                       if ($unknownValues) {\r
-                               $this->DieUsage("Unrecognised value" . (count($unknownValues) > 1 ? "s '" : " '") . implode("', '", $unknownValues) . "' for parameter '$valueName'", "unknown_$valueName");\r
-                       }\r
-               }\r
-\r
-               return $allowMultiple ? $valuesList : $valuesList[0];\r
-       }\r
-\r
-       /**\r
-        * Call main module's error handler \r
-        */\r
-       public function DieUsage($description, $errorCode, $httpRespCode = 0) {\r
-               $this->GetMain()->MainDieUsage($description, $errorCode, $httpRespCode);\r
-       }\r
-\r
-       protected function DieDebug($message) {\r
-               wfDebugDieBacktrace("Internal error in '{get_class($this)}': $message");\r
-       }\r
-}\r
-?>
\ No newline at end of file
+<?php
+
+/*
+ * Created on Sep 5, 2006
+ *
+ * API for MediaWiki 1.8+
+ *
+ * Copyright (C) 2006 Yuri Astrakhan <Firstname><Lastname>@gmail.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/**
+ * This abstract class implements many basic API functions, and is the base of all API classes.
+ * The class functions are divided into several areas of functionality:
+ * 
+ * Module parameters: Derived classes can define getAllowedParams() to specify which parameters to expect,
+ *     how to parse and validate them.
+ * 
+ * Profiling: various methods to allow keeping tabs on various tasks and their time costs
+ * 
+ * Self-documentation: code to allow api to document its own state.
+ * 
+ * @addtogroup API
+ */
+abstract class ApiBase {
+
+       // These constants allow modules to specify exactly how to treat incomming parameters.
+
+       const PARAM_DFLT = 0;
+       const PARAM_ISMULTI = 1;
+       const PARAM_TYPE = 2;
+       const PARAM_MAX = 3;
+       const PARAM_MAX2 = 4;
+       const PARAM_MIN = 5;
+
+       const LIMIT_BIG1 = 500; // Fast query, std user limit
+       const LIMIT_BIG2 = 5000; // Fast query, bot/sysop limit
+       const LIMIT_SML1 = 50; // Slow query, std user limit
+       const LIMIT_SML2 = 500; // Slow query, bot/sysop limit
+
+       private $mMainModule, $mModuleName, $mParamPrefix;
+
+       /**
+       * Constructor
+       */
+       public function __construct($mainModule, $moduleName, $paramPrefix = '') {
+               $this->mMainModule = $mainModule;
+               $this->mModuleName = $moduleName;
+               $this->mParamPrefix = $paramPrefix;
+       }
+
+       /**
+        * Executes this module
+        */
+       public abstract function execute();
+
+       /**
+        * Get the name of the module being executed by this instance 
+        */
+       public function getModuleName() {
+               return $this->mModuleName;
+       }
+
+       /**
+        * Get parameter prefix (usually two letters or an empty string). 
+        */
+       public function getParamPrefix() {
+               return $this->mParamPrefix;
+       }       
+
+       /**
+        * Get the name of the module as shown in the profiler log 
+        */
+       public function getModuleProfileName($db = false) {
+               if ($db)
+                       return 'API:' . $this->mModuleName . '-DB';
+               else
+                       return 'API:' . $this->mModuleName;
+       }
+
+       /**
+        * Get main module
+        */
+       public function getMain() {
+               return $this->mMainModule;
+       }
+
+       /**
+        * If this module's $this is the same as $this->mMainModule, its the root, otherwise no
+        */
+       public function isMain() {
+               return $this === $this->mMainModule;
+       }
+
+       /**
+        * Get result object
+        */
+       public function getResult() {
+               // Main module has getResult() method overriden
+               // Safety - avoid infinite loop:
+               if ($this->isMain())
+                       ApiBase :: dieDebug(__METHOD__, 'base method was called on main module. ');
+               return $this->getMain()->getResult();
+       }
+
+       /**
+        * Get the result data array
+        */
+       public function & getResultData() {
+               return $this->getResult()->getData();
+       }
+
+       /**
+        * If the module may only be used with a certain format module,
+        * it should override this method to return an instance of that formatter.
+        * A value of null means the default format will be used.  
+        */
+       public function getCustomPrinter() {
+               return null;
+       }
+
+       /**
+        * Generates help message for this module, or false if there is no description
+        */
+       public function makeHelpMsg() {
+
+               static $lnPrfx = "\n  ";
+
+               $msg = $this->getDescription();
+
+               if ($msg !== false) {
+
+                       if (!is_array($msg))
+                               $msg = array (
+                                       $msg
+                               );
+                       $msg = $lnPrfx . implode($lnPrfx, $msg) . "\n";
+
+                       // Parameters
+                       $paramsMsg = $this->makeHelpMsgParameters();
+                       if ($paramsMsg !== false) {
+                               $msg .= "Parameters:\n$paramsMsg";
+                       }
+
+                       // Examples
+                       $examples = $this->getExamples();
+                       if ($examples !== false) {
+                               if (!is_array($examples))
+                                       $examples = array (
+                                               $examples
+                                       );
+                               $msg .= 'Example' . (count($examples) > 1 ? 's' : '') . ":\n  ";
+                               $msg .= implode($lnPrfx, $examples) . "\n";
+                       }
+
+                       if ($this->getMain()->getShowVersions()) {
+                               $versions = $this->getVersion();
+                               $pattern = '(\$.*) ([0-9a-z_]+\.php) (.*\$)';
+                               $replacement = '\\0' . "\n    " . 'http://svn.wikimedia.org/viewvc/mediawiki/trunk/phase3/includes/api/\\2';
+                               
+                               if (is_array($versions)) {
+                                       foreach ($versions as &$v)
+                                               $v = eregi_replace($pattern, $replacement, $v);
+                                       $versions = implode("\n  ", $versions);
+                               }
+                               else
+                                       $versions = eregi_replace($pattern, $replacement, $versions);
+
+                               $msg .= "Version:\n  $versions\n";
+                       }
+               }
+
+               return $msg;
+       }
+
+       public function makeHelpMsgParameters() {
+               $params = $this->getAllowedParams();
+               if ($params !== false) {
+
+                       $paramsDescription = $this->getParamDescription();
+                       $msg = '';
+                       $paramPrefix = "\n" . str_repeat(' ', 19);
+                       foreach ($params as $paramName => $paramSettings) {
+                               $desc = isset ($paramsDescription[$paramName]) ? $paramsDescription[$paramName] : '';
+                               if (is_array($desc))
+                                       $desc = implode($paramPrefix, $desc);
+
+                               @ $type = $paramSettings[self :: PARAM_TYPE];
+                               if (isset ($type)) {
+                                       if (isset ($paramSettings[self :: PARAM_ISMULTI]))
+                                               $prompt = 'Values (separate with \'|\'): ';
+                                       else
+                                               $prompt = 'One value: ';
+
+                                       if (is_array($type)) {
+                                               $choices = array();
+                                               $nothingPrompt = false;
+                                               foreach ($type as $t)
+                                                       if ($t=='')
+                                                               $nothingPrompt = 'Can be empty, or ';
+                                                       else
+                                                               $choices[] =  $t;
+                                               $desc .= $paramPrefix . $nothingPrompt . $prompt . implode(', ', $choices);
+                                       } else {
+                                               switch ($type) {
+                                                       case 'namespace':
+                                                               // Special handling because namespaces are type-limited, yet they are not given
+                                                               $desc .= $paramPrefix . $prompt . implode(', ', ApiBase :: getValidNamespaces());
+                                                               break;
+                                                       case 'limit':
+                                                               $desc .= $paramPrefix . "No more than {$paramSettings[self :: PARAM_MAX]} ({$paramSettings[self :: PARAM_MAX2]} for bots) allowed.";
+                                                               break;
+                                                       case 'integer':
+                                                               $hasMin = isset($paramSettings[self :: PARAM_MIN]);
+                                                               $hasMax = isset($paramSettings[self :: PARAM_MAX]);
+                                                               if ($hasMin || $hasMax) {
+                                                                       if (!$hasMax)
+                                                                               $intRangeStr = "The value must be no less than {$paramSettings[self :: PARAM_MIN]}";
+                                                                       elseif (!$hasMin)
+                                                                               $intRangeStr = "The value must be no more than {$paramSettings[self :: PARAM_MAX]}";
+                                                                       else
+                                                                               $intRangeStr = "The value must be between {$paramSettings[self :: PARAM_MIN]} and {$paramSettings[self :: PARAM_MAX]}";
+                                                                               
+                                                                       $desc .= $paramPrefix . $intRangeStr;
+                                                               }
+                                                               break;
+                                               }
+                                       }
+                               }
+
+                               $default = is_array($paramSettings) ? (isset ($paramSettings[self :: PARAM_DFLT]) ? $paramSettings[self :: PARAM_DFLT] : null) : $paramSettings;
+                               if (!is_null($default) && $default !== false)
+                                       $desc .= $paramPrefix . "Default: $default";
+
+                               $msg .= sprintf("  %-14s - %s\n", $this->encodeParamName($paramName), $desc);
+                       }
+                       return $msg;
+
+               } else
+                       return false;
+       }
+
+       /**
+        * Returns the description string for this module
+        */
+       protected function getDescription() {
+               return false;
+       }
+
+       /**
+        * Returns usage examples for this module. Return null if no examples are available.
+        */
+       protected function getExamples() {
+               return false;
+       }
+
+       /**
+        * Returns an array of allowed parameters (keys) => default value for that parameter
+        */
+       protected function getAllowedParams() {
+               return false;
+       }
+
+       /**
+        * Returns the description string for the given parameter.
+        */
+       protected function getParamDescription() {
+               return false;
+       }
+
+       /**
+        * This method mangles parameter name based on the prefix supplied to the constructor.
+        * Override this method to change parameter name during runtime 
+        */
+       public function encodeParamName($paramName) {
+               return $this->mParamPrefix . $paramName;
+       }
+
+       /**
+       * Using getAllowedParams(), makes an array of the values provided by the user,
+       * with key being the name of the variable, and value - validated value from user or default.
+       * This method can be used to generate local variables using extract().
+       */
+       public function extractRequestParams() {
+               $params = $this->getAllowedParams();
+               $results = array ();
+
+               foreach ($params as $paramName => $paramSettings)
+                       $results[$paramName] = $this->getParameterFromSettings($paramName, $paramSettings);
+
+               return $results;
+       }
+
+       /**
+        * Get a value for the given parameter 
+        */
+       protected function getParameter($paramName) {
+               $params = $this->getAllowedParams();
+               $paramSettings = $params[$paramName];
+               return $this->getParameterFromSettings($paramName, $paramSettings);
+       }
+
+       public static function getValidNamespaces() {
+               static $mValidNamespaces = null;
+               if (is_null($mValidNamespaces)) {
+
+                       global $wgContLang;
+                       $mValidNamespaces = array ();
+                       foreach (array_keys($wgContLang->getNamespaces()) as $ns) {
+                               if ($ns >= 0)
+                                       $mValidNamespaces[] = $ns;
+                       }
+               }
+               return $mValidNamespaces;
+       }
+
+       /**
+        * Using the settings determine the value for the given parameter
+        * @param $paramName String: parameter name
+        * @param $paramSettings Mixed: default value or an array of settings using PARAM_* constants.
+        */
+       protected function getParameterFromSettings($paramName, $paramSettings) {
+
+               // Some classes may decide to change parameter names
+               $paramName = $this->encodeParamName($paramName);
+
+               if (!is_array($paramSettings)) {
+                       $default = $paramSettings;
+                       $multi = false;
+                       $type = gettype($paramSettings);
+               } else {
+                       $default = isset ($paramSettings[self :: PARAM_DFLT]) ? $paramSettings[self :: PARAM_DFLT] : null;
+                       $multi = isset ($paramSettings[self :: PARAM_ISMULTI]) ? $paramSettings[self :: PARAM_ISMULTI] : false;
+                       $type = isset ($paramSettings[self :: PARAM_TYPE]) ? $paramSettings[self :: PARAM_TYPE] : null;
+
+                       // When type is not given, and no choices, the type is the same as $default
+                       if (!isset ($type)) {
+                               if (isset ($default))
+                                       $type = gettype($default);
+                               else
+                                       $type = 'NULL'; // allow everything
+                       }
+               }
+
+               if ($type == 'boolean') {
+                       if (isset ($default) && $default !== false) {
+                               // Having a default value of anything other than 'false' is pointless
+                               ApiBase :: dieDebug(__METHOD__, "Boolean param $paramName's default is set to '$default'");
+                       }
+
+                       $value = $this->getMain()->getRequest()->getCheck($paramName);
+               } else {
+                       $value = $this->getMain()->getRequest()->getVal($paramName, $default);
+
+                       if (isset ($value) && $type == 'namespace')
+                               $type = ApiBase :: getValidNamespaces();
+               }
+
+               if (isset ($value) && ($multi || is_array($type)))
+                       $value = $this->parseMultiValue($paramName, $value, $multi, is_array($type) ? $type : null);
+
+               // More validation only when choices were not given
+               // choices were validated in parseMultiValue()
+               if (isset ($value)) {
+                       if (!is_array($type)) {
+                               switch ($type) {
+                                       case 'NULL' : // nothing to do
+                                               break;
+                                       case 'string' : // nothing to do
+                                               break;
+                                       case 'integer' : // Force everything using intval() and optionally validate limits
+
+                                               $value = is_array($value) ? array_map('intval', $value) : intval($value);
+                                               $checkMin = isset ($paramSettings[self :: PARAM_MIN]);
+                                               $checkMax = isset ($paramSettings[self :: PARAM_MAX]);
+                                               
+                                               if ($checkMin || $checkMax) {
+                                                       $min = $checkMin ? $paramSettings[self :: PARAM_MIN] : false;
+                                                       $max = $checkMax ? $paramSettings[self :: PARAM_MAX] : false;
+                                               
+                                                       $values = is_array($value) ? $value : array($value);
+                                                       foreach ($values as $v) {
+                                                               if ($checkMin && $v < $min)
+                                                                       $this->dieUsage("$paramName may not be less than $min (set to $v)", $paramName);
+                                                               if ($checkMax && $v > $max)
+                                                                       $this->dieUsage("$paramName may not be over $max (set to $v)", $paramName);
+                                                       }
+                                               }
+                                               break;
+                                       case 'limit' :
+                                               if (!isset ($paramSettings[self :: PARAM_MAX]) || !isset ($paramSettings[self :: PARAM_MAX2]))
+                                                       ApiBase :: dieDebug(__METHOD__, "MAX1 or MAX2 are not defined for the limit $paramName");
+                                               if ($multi)
+                                                       ApiBase :: dieDebug(__METHOD__, "Multi-values not supported for $paramName");
+                                               $min = isset ($paramSettings[self :: PARAM_MIN]) ? $paramSettings[self :: PARAM_MIN] : 0;
+                                               $value = intval($value);
+                                               $this->validateLimit($paramName, $value, $min, $paramSettings[self :: PARAM_MAX], $paramSettings[self :: PARAM_MAX2]);
+                                               break;
+                                       case 'boolean' :
+                                               if ($multi)
+                                                       ApiBase :: dieDebug(__METHOD__, "Multi-values not supported for $paramName");
+                                               break;
+                                       case 'timestamp' :
+                                               if ($multi)
+                                                       ApiBase :: dieDebug(__METHOD__, "Multi-values not supported for $paramName");
+                                               $value = wfTimestamp(TS_UNIX, $value);
+                                               if ($value === 0)
+                                                       $this->dieUsage("Invalid value '$value' for timestamp parameter $paramName", "badtimestamp_{$paramName}");
+                                               $value = wfTimestamp(TS_MW, $value);
+                                               break;
+                                       case 'user' :
+                                               $title = Title::makeTitleSafe( NS_USER, $value );
+                                               if ( is_null( $title ) )
+                                                       $this->dieUsage("Invalid value $user for user parameter $paramName", "baduser_{$paramName}");
+                                               $value = $title->getText();
+                                               break;
+                                       default :
+                                               ApiBase :: dieDebug(__METHOD__, "Param $paramName's type is unknown - $type");
+                               }
+                       }
+
+                       // There should never be any duplicate values in a list
+                       if (is_array($value))
+                               $value = array_unique($value);
+               }
+
+               return $value;
+       }
+
+       /**
+       * Return an array of values that were given in a 'a|b|c' notation,
+       * after it optionally validates them against the list allowed values.
+       * 
+       * @param valueName - The name of the parameter (for error reporting)
+       * @param value - The value being parsed
+       * @param allowMultiple - Can $value contain more than one value separated by '|'?
+       * @param allowedValues - An array of values to check against. If null, all values are accepted.
+       * @return (allowMultiple ? an_array_of_values : a_single_value) 
+       */
+       protected function parseMultiValue($valueName, $value, $allowMultiple, $allowedValues) {
+               $valuesList = explode('|', $value);
+               if (!$allowMultiple && count($valuesList) != 1) {
+                       $possibleValues = is_array($allowedValues) ? "of '" . implode("', '", $allowedValues) . "'" : '';
+                       $this->dieUsage("Only one $possibleValues is allowed for parameter '$valueName'", "multival_$valueName");
+               }
+               if (is_array($allowedValues)) {
+                       $unknownValues = array_diff($valuesList, $allowedValues);
+                       if ($unknownValues) {
+                               $this->dieUsage('Unrecognised value' . (count($unknownValues) > 1 ? "s" : "") . " for parameter '$valueName'", "unknown_$valueName");
+                       }
+               }
+
+               return $allowMultiple ? $valuesList : $valuesList[0];
+       }
+
+       /**
+       * Validate the value against the minimum and user/bot maximum limits. Prints usage info on failure.
+       */
+       function validateLimit($varname, $value, $min, $max, $botMax) {
+               if ($value < $min) {
+                       $this->dieUsage("$varname may not be less than $min (set to $value)", $varname);
+               }
+
+               if ($this->getMain()->isBot() || $this->getMain()->isSysop()) {
+                       if ($value > $botMax) {
+                               $this->dieUsage("$varname may not be over $botMax (set to $value) for bots or sysops", $varname);
+                       }
+               }
+               elseif ($value > $max) {
+                       $this->dieUsage("$varname may not be over $max (set to $value) for users", $varname);
+               }
+       }
+
+       /**
+        * Call main module's error handler 
+        */
+       public function dieUsage($description, $errorCode, $httpRespCode = 0) {
+               throw new UsageException($description, $this->encodeParamName($errorCode), $httpRespCode);
+       }
+
+       /**
+        * Internal code errors should be reported with this method
+        */
+       protected static function dieDebug($method, $message) {
+               wfDebugDieBacktrace("Internal error in $method: $message");
+       }
+
+       /**
+        * Profiling: total module execution time
+        */
+       private $mTimeIn = 0, $mModuleTime = 0;
+
+       /**
+        * Start module profiling
+        */
+       public function profileIn() {
+               if ($this->mTimeIn !== 0)
+                       ApiBase :: dieDebug(__METHOD__, 'called twice without calling profileOut()');
+               $this->mTimeIn = microtime(true);
+               wfProfileIn($this->getModuleProfileName());
+       }
+
+       /**
+        * End module profiling
+        */
+       public function profileOut() {
+               if ($this->mTimeIn === 0)
+                       ApiBase :: dieDebug(__METHOD__, 'called without calling profileIn() first');
+               if ($this->mDBTimeIn !== 0)
+                       ApiBase :: dieDebug(__METHOD__, 'must be called after database profiling is done with profileDBOut()');
+
+               $this->mModuleTime += microtime(true) - $this->mTimeIn;
+               $this->mTimeIn = 0;
+               wfProfileOut($this->getModuleProfileName());
+       }
+
+       /**
+        * When modules crash, sometimes it is needed to do a profileOut() regardless
+        * of the profiling state the module was in. This method does such cleanup. 
+        */
+       public function safeProfileOut() {
+               if ($this->mTimeIn !== 0) {
+                       if ($this->mDBTimeIn !== 0)
+                               $this->profileDBOut();
+                       $this->profileOut();
+               }
+       }
+
+       /**
+        * Total time the module was executed
+        */
+       public function getProfileTime() {
+               if ($this->mTimeIn !== 0)
+                       ApiBase :: dieDebug(__METHOD__, 'called without calling profileOut() first');
+               return $this->mModuleTime;
+       }
+
+       /**
+        * Profiling: database execution time
+        */
+       private $mDBTimeIn = 0, $mDBTime = 0;
+
+       /**
+        * Start module profiling
+        */
+       public function profileDBIn() {
+               if ($this->mTimeIn === 0)
+                       ApiBase :: dieDebug(__METHOD__, 'must be called while profiling the entire module with profileIn()');
+               if ($this->mDBTimeIn !== 0)
+                       ApiBase :: dieDebug(__METHOD__, 'called twice without calling profileDBOut()');
+               $this->mDBTimeIn = microtime(true);
+               wfProfileIn($this->getModuleProfileName(true));
+       }
+
+       /**
+        * End database profiling
+        */
+       public function profileDBOut() {
+               if ($this->mTimeIn === 0)
+                       ApiBase :: dieDebug(__METHOD__, 'must be called while profiling the entire module with profileIn()');
+               if ($this->mDBTimeIn === 0)
+                       ApiBase :: dieDebug(__METHOD__, 'called without calling profileDBIn() first');
+
+               $time = microtime(true) - $this->mDBTimeIn;
+               $this->mDBTimeIn = 0;
+
+               $this->mDBTime += $time;
+               $this->getMain()->mDBTime += $time;
+               wfProfileOut($this->getModuleProfileName(true));
+       }
+
+       /**
+        * Total time the module used the database
+        */
+       public function getProfileDBTime() {
+               if ($this->mDBTimeIn !== 0)
+                       ApiBase :: dieDebug(__METHOD__, 'called without calling profileDBOut() first');
+               return $this->mDBTime;
+       }
+       
+       public static function debugPrint($value, $name = 'unknown', $backtrace = false) {
+               print "\n\n<pre><b>Debuging value '$name':</b>\n\n";
+               var_export($value);
+               if ($backtrace)
+                       print "\n" . wfBacktrace();
+               print "\n</pre>\n";
+       }
+
+       public abstract function getVersion();
+
+       public static function getBaseVersion() {
+               return __CLASS__ . ': $Id$';
+       }
+}
+?>