Difference between revisions of "StringFunctions extension"

Revision as of 06:50, 12 September 2007

This is a slightly modified version of StringFunctions. Its replace function allows you to use regular expressions as it uses preg_replace.

This allows to make systematic replacements within a text, like in the followng example:

• we have a string consisting of comma sepoarated words
• we want to convert the words into hyperlinks to articles
• so that Main Page, DPL:Manual, Special:Recent Changes would become
• {{#vardefine:x|Main Page, DPL:Manual, Special:Recent Changes}}{{#replace:{{#replace:{{#var:x}},|/ *([^,]+)/| \1}}|/,$/|}}

The code looks like this

 {{#replace:{{#replace:{{{1|}}},|/ *([^,]+)/| [[\1]]}}|/,$/|}}

The inner replace looks for comma separated tokerns and puts brackets around them. It adds a final comma to the sesarch string so that also the last token matches. The outer replace statement removes that final comma again.

<?php /*

Defines a subset of parser functions that operate with strings.

{{#len:value}}

Returns the length of the given value.
See: http://php.net/manual/function.strlen.php


{{#pos:value|key|offset}}

Returns the first position of key inside the given value, or an empty string.
If offset is defined, this method will not search the first offset characters.
See: http://php.net/manual/function.strpos.php


{{#rpos:value|key}}

Returns the last position of key inside the given value, or -1 if the key is
not found. When using this to search for the last delimiter, add +1 to the
result to retreive position after the last delimiter. This also works when
the delimiter is not found, because "-1 + 1" is zero, which is the beginning
of the given value.
See: http://php.net/manual/function.strrpos.php


{{#sub:value|start|length}}

Returns a substring of the given value with the given starting position and
length. If length is omitted, this returns the rest of the string.
See: http://php.net/manual/function.substr.php


{{#pad:value|length|with|direction}}

Returns the value padded to the certain length with the given with string.
If the with string is not given, spaces are used for padding. The direction
may be specified as: 'left', 'center' or 'right'.
See: http://php.net/manual/function.str-pad.php


{{#replace:value|from|to}}

Returns the given value with all occurences of 'from' replaced with 'to'.
See: http://php.net/manual/function.str-replace.php


{{#explode:value|delimiter|position}}

Splits the given value into pieces by the given delimiter and returns the
position-th piece. Empty string is returned if there are not enough pieces.
Note: Pieces are counted from 0.
See: http://php.net/manual/function.explode.php


{{#urlencode:value}}

URL-encodes the given value.
See: http://php.net/manual/function.urlencode.php


{{#urldecode:value}}

URL-decodes the given value.
See: http://php.net/manual/function.urldecode.php


Contributors:
  Juraj Simlovic [1]
  Algorithm [2]

• /

$wgExtensionCredits['parserhook'][] = array( 'name' => 'StringFunctions', 'version' => '1.9.3', // Jan 30, 2007. 'description' => 'Enhances parser with string functions', 'author' => 'Juraj Simlovic', 'url' => 'http://www.mediawiki.org/wiki/Extension:StringFunctions', );

$wgExtensionFunctions[] = 'wfStringFunctions';

$wgHooks['LanguageGetMagic'][] = 'wfStringFunctionsLanguageGetMagic';

function wfStringFunctions ( ) {

   global $wgParser, $wgExtStringFunctions;
   global $wgStringFunctionsLimitSearch, $wgStringFunctionsLimitReplace, $wgStringFunctionsLimitPad;

   $wgExtStringFunctions = new ExtStringFunctions ( );
   $wgStringFunctionsLimitSearch  =  30;
   $wgStringFunctionsLimitReplace =  30;
   $wgStringFunctionsLimitPad     = 100;

   $wgParser->setFunctionHook ( 'len',       array ( &$wgExtStringFunctions, 'runLen'       ) );

   $wgParser->setFunctionHook ( 'pos',       array ( &$wgExtStringFunctions, 'runPos'       ) );
   $wgParser->setFunctionHook ( 'rpos',      array ( &$wgExtStringFunctions, 'runRPos'      ) );

   $wgParser->setFunctionHook ( 'sub',       array ( &$wgExtStringFunctions, 'runSub'       ) );

   $wgParser->setFunctionHook ( 'pad',       array ( &$wgExtStringFunctions, 'runPad'       ) );

   $wgParser->setFunctionHook ( 'replace',   array ( &$wgExtStringFunctions, 'runReplace'   ) );

   $wgParser->setFunctionHook ( 'explode',   array ( &$wgExtStringFunctions, 'runExplode'   ) );

   $wgParser->setFunctionHook ( 'urlencode', array ( &$wgExtStringFunctions, 'runUrlEncode' ) );
   $wgParser->setFunctionHook ( 'urldecode', array ( &$wgExtStringFunctions, 'runUrlDecode' ) );

}

function wfStringFunctionsLanguageGetMagic( &$magicWords, $langCode = "en" ) {

   switch ( $langCode ) {
       default:
           $magicWords['len']          = array ( 0, 'len' );
           $magicWords['pos']          = array ( 0, 'pos' );
           $magicWords['rpos']         = array ( 0, 'rpos' );
           $magicWords['sub']          = array ( 0, 'sub' );
           $magicWords['pad']          = array ( 0, 'pad' );
           $magicWords['replace']      = array ( 0, 'replace' );
           $magicWords['explode']      = array ( 0, 'explode' );
           $magicWords['urlencode']    = array ( 0, 'urlencode' );
           $magicWords['urldecode']    = array ( 0, 'urldecode' );
   }
   return true;

}

class ExtStringFunctions {

   /**
    * {{#len:value}}
    */
   function runLen ( &$parser, $inStr =  ) 
   {
       return mb_strlen ( $inStr );
   }

   /**
    * {{#pos:value|key|offset}}
    * Note: If the needle is an empty string, single space is used instead.
    * Note: If the needle is not found, empty string is returned.
    * Note: The needle is limited to specific length.
    */
   function runPos ( &$parser, $inStr = , $inNeedle = , $inOffset = 0 ) 
   {
       global $wgStringFunctionsLimitSearch;

       # empty needle
       if ( $inNeedle ===  ) 
           $inNeedle = ' ';

       # limit needle
       $inNeedle = mb_substr ( $inNeedle, 0, $wgStringFunctionsLimitSearch );

       # strpos
       $ret = mb_strpos ( $inStr, $inNeedle, intval ( $inOffset ) );

       # return empty string upon not found
       return ( $ret !== FALSE ) ? $ret : ;
   }

   /**
    * {{#rpos:value|key}}
    * Note: If the needle is an empty string, single space is used instead.
    * Note: If the needle is not found, -1 is returned.
    * Note: The needle is limited to specific length.
    */
   function runRPos ( &$parser, $inStr = , $inNeedle =  ) 
   {
       global $wgStringFunctionsLimitSearch;

       # empty needle
       if ( $inNeedle ==  )
           $inNeedle = ' ';

       # limit needle
       $inNeedle = mb_substr ( $inNeedle, 0, $wgStringFunctionsLimitSearch );

       # empty haystack
       if ( $inStr ==  )
           return "-1";

       # strrpos
       $ret = mb_strrpos ( $inStr, $inNeedle );

       # return -1 upon not found
       return ( $ret !== FALSE ) ? $ret : "-1";
   }

   /**
    * {{#sub:value|start|length}}
    * Note: If length is zero, the rest of the input is returned.
    */
   function runSub ( &$parser, $inStr = , $inStart = , $inLength = 0 ) 
   {
       # zero length
       if ( ! ( (int) $inLength ) ) 
           return mb_substr ( $inStr, intval ( $inStart ) );

       # non-zero length
       return mb_substr ( $inStr, intval ( $inStart ) , intval ( $inLength ) );
   }

   /**
    * {{#pad:value|length|with|direction}}
    * Note: Length of the resulting string is limited.
    */
   function runPad ( &$parser, $inStr = , $inLen = 0, $inWith = , $inDirection = 'left' ) 
   {
       global $wgStringFunctionsLimitPad;

       # direction
       switch ( strtolower ( $inDirection ) ) 
       {
       case 'left':
       default:
         $direction = STR_PAD_LEFT;
         break;
       case 'center':
         $direction = STR_PAD_BOTH;
         break;
       case 'right':
         $direction = STR_PAD_RIGHT;
         break;
       }

       #limit pad length
       if ($wgStringFunctionsLimitPad > 0)
           $inLen = min ( intval ( $inLen ), $wgStringFunctionsLimitPad );

       # padding
       if ( $inWith ==  )
           $inWith = ' ';

       # pad
       return str_pad ( $inStr, intval ( $inLen ), $inWith, $direction );
   }

   /**
    * {{#replace:value|from|to}}
    * Note: If the needle is an empty string, single space is used instead.
    * Note: The needle is limited to specific length.
    * Note: The product is limited to specific length.
    */
   function runReplace ( &$parser, $inStr = , $inReplaceFrom = , $inReplaceTo =  ) 
   {
       global $wgStringFunctionsLimitSearch, $wgStringFunctionsLimitReplace;

       # empty needle
       if ( $inReplaceFrom ==  ) 
           $inReplaceFrom = ' ';

       # limit needle (this is being searched for)
       $inReplaceFrom = mb_substr ( $inReplaceFrom, 0, $wgStringFunctionsLimitSearch );

       # limit product (this is being returned)
       $inReplaceTo = mb_substr ( $inReplaceTo, 0, $wgStringFunctionsLimitReplace );

       # replace
       if ($inReplaceFrom[0]!=$inReplaceFrom[strlen($inReplaceFrom)-1] || strlen($inReplaceFrom)<=2 ) {

$inReplaceFrom='`'.str_replace('`','\`',$inReplaceFrom).'`';

       }
       return preg_replace ( $inReplaceFrom, $inReplaceTo, $inStr );
   }

   /**
    * {{#explode:value|delimiter|position}}
    * Note: If the divider is an empty string, single space is used instead.
    * Note: The divider is limited to specific length.
    * Note: Empty string is returned, if there is not enough exploded chunks.
    */
   function runExplode ( &$parser, $inStr = , $inDiv = , $inPos = 0 ) 
   {
       global $wgStringFunctionsLimitSearch;

       # empty divider
       if ( $inDiv ==  )
           $inDiv = ' ';

       # limit divider (this is being searched for)
       $inDiv = mb_substr ( $inDiv, 0, $wgStringFunctionsLimitSearch );

       # explode
       $tokens = explode ( $inDiv, $inStr );

       # out of range
       if ( !isset ( $tokens [ intval ( $inPos ) ] ) ) 
           return "";

       # in range
       return $tokens [ intval ( $inPos ) ];
   }

   /**
    * {{#urlencode:value}}
    */
   function runUrlEncode ( &$parser, $inStr =  ) 
   {
       # encode
       return urlencode ( $inStr );
   }

   /**
    * {{#urldecode:value}}
    */
   function runUrlDecode ( &$parser, $inStr =  ) 
   {
       # decode
       return urldecode ( $inStr );
   }

}

?> </nowiki></pre>