Added crop()

Improved substr() to allow negative values for start and len

git-svn-id: https://svn.typo3.org/TYPO3v4/Core/trunk@201 709f56b5-9817-0410-a4d7-c38de5d9e867

diff --git a/t3lib/class.t3lib_cs.php b/t3lib/class.t3lib_cs.php
index daf18db..5ab49bf 100755 (executable)
--- a/t3lib/class.t3lib_cs.php
+++ b/t3lib/class.t3lib_cs.php
@@ -828,6 +828,8 @@ class t3lib_cs {
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
         */
        function strtrunc($charset,$string,$len)        {
+               if ($len <= 0)  return '';
+
                if ($GLOBALS['TYPO3_CONF_VARS']['SYS']['t3lib_cs_utils'] == 'mbstring') {
                        return mb_strcut($string,0,$len,$charset);
                } elseif ($charset == 'utf-8')  {
@@ -849,15 +851,12 @@ class t3lib_cs {
        /**
         * Returns a part of a string.
         *
-        *
-        * Negative values for @arg $start and @arg $len are currently not supported.
-        *
         * @param       string          the character set
         * @param       string          character string
-        * @param       int             $start  start position (character position)
+        * @param       int             start position (character position)
         * @param       int             length (in characters)
         * @return      string          the substring
-        * @see substr()
+        * @see substr(), mb_substr()
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
         * @bug
         */
@@ -927,7 +926,7 @@ class t3lib_cs {
         * @param       string          string
         * @return      string          the converted string
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
-        * @see strtolower(), strtoupper(), mb_convert_case()
+        * @see strtolower(), strtoupper()
         */
        function conv_case($charset,$string,$case)      {
                if ($GLOBALS['TYPO3_CONF_VARS']['SYS']['t3lib_cs_utils'] == 'mbstring' &&
@@ -982,7 +981,7 @@ class t3lib_cs {
 
        /********************************************
         *
-        * UTF-8 string operation functions
+        * Internal UTF-8 string operation functions
         *
         ********************************************/
 
@@ -996,8 +995,6 @@ class t3lib_cs {
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
         */
        function utf8_strtrunc($str,$len)       {
-               if ($len <= 0)  return '';
-
                $i = $len-1;
                if (ord($str{$i}) & 0x80) { // part of a multibyte sequence
                        for (; $i>0 && !(ord($str{$i}) & 0x40); $i--)   ;       // find the first byte
@@ -1012,9 +1009,6 @@ class t3lib_cs {
        /**
         * Returns a part of a UTF-8 string.
         *
-        *
-        * Negative values for @arg $start and @arg $len are currently not supported.
-        *
         * @param       string          $str    UTF-8 string
         * @param       int             $start  start position (character position)
         * @param       int             $len    length (in characters)
@@ -1023,8 +1017,6 @@ class t3lib_cs {
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
         */
        function utf8_substr($str,$start,$len=null)     {
-               if ($len===0)   return '';
-
                $byte_start = $this->utf8_char2byte_pos($str,$start);
                if ($byte_start === false)      return false;   // $start outside string length
 
@@ -1108,13 +1100,23 @@ class t3lib_cs {
         * Translates a character position into an 'absolute' byte position.
         *
         * @param       string          UTF-8 string
-        * @param       int             character position
+        * @param       int             character position (negative values start from the end)
         * @return      int             byte position
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
         */
        function utf8_char2byte_pos($str,$pos)  {
-               $n = 0; // number of characters
-               for($i=0; $str{$i} && $n<$pos; $i++)    {
+               $n = 0;         // number of characters found
+               $p = abs($pos); // number of characters wanted
+
+               if ($pos >= 0)  {
+                       $i = 0;
+                       $d = 1;
+               } else {
+                       $i = strlen($str)-1;
+                       $d = -1;
+               }
+
+               for( ; $str{$i} && $n<$p; $i+=d)        {
                        $c = (int)ord($str{$i});
                        if (!($c & 0x80))       // single-byte (0xxxxxx)
                                $n++;
@@ -1123,8 +1125,13 @@ class t3lib_cs {
                }
                if (!$str{$i})  return false; // offset beyond string length
 
-                       // skip trailing multi-byte data bytes
-               while ((ord($str{$i}) & 0x80) && !(ord($str{$i}) & 0x40)) { $i++; }
+               if ($pos >= 0)  {
+                               // skip trailing multi-byte data bytes
+                       while ((ord($str{$i}) & 0x80) && !(ord($str{$i}) & 0x40)) { $i++; }
+               } else {
+                               // correct offset
+                       $i++;
+               }
 
                return $i;
        }
@@ -1205,7 +1212,7 @@ class t3lib_cs {
 
        /********************************************
         *
-        * EUC string operation functions
+        * Internal EUC string operation functions
         *
         * Extended Unix Code:
         *  ASCII compatible 7bit single bytes chars
@@ -1226,8 +1233,6 @@ class t3lib_cs {
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
         */
        function euc_strtrunc($str,$len,$charset)        {
-               if ($len <= 0)  return '';
-
                $sjis = ($charset == 'shift_jis');
                for ($i=0; $str{$i} && $i<$len; $i++) {
                        $c = ord($str{$i});
@@ -1249,9 +1254,6 @@ class t3lib_cs {
        /**
         * Returns a part of a string in the EUC charset family.
         *
-        *
-        * Negative values for @arg $start and @arg $len are currently not supported.
-        *
         * @param       string          EUC multibyte character string
         * @param       int             start position (character position)
         * @param       string          the charset
@@ -1260,8 +1262,6 @@ class t3lib_cs {
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
         */
        function euc_substr($str,$start,$charset,$len=null)     {
-               if ($len===0)   return '';
-
                $byte_start = $this->euc_char2byte_pos($str,$start,$charset);
                if ($byte_start === false)      return false;   // $start outside string length
 
@@ -1308,7 +1308,7 @@ class t3lib_cs {
         * Translates a character position into an 'absolute' byte position.
         *
         * @param       string          EUC multibyte character string
-        * @param       int             character position
+        * @param       int             character position (negative values start from the end)
         * @param       string          the charset
         * @return      int             byte position
         * @author      Martin Kutschker <martin.t.kutschker@blackbox.net>
@@ -1316,19 +1316,31 @@ class t3lib_cs {
        function euc_char2byte_pos($str,$pos,$charset)  {
                $sjis = ($charset == 'shift_jis');
                $n = 0; // number of characters seen
-               for ($i=0; $str{$i} && $n<$pos; $i++) {
+               $p = abs($pos); // number of characters wanted
+
+               if ($pos >= 0)  {
+                       $i = 0;
+                       $d = 1;
+               } else {
+                       $i = strlen($str)-1;
+                       $d = -1;
+               }
+
+               for ( ; $str{$i} && $n<$p; $i+=$d) {
                        $c = ord($str{$i});
                        if ($sjis)      {
-                               if (($c >= 0x80 && $c < 0xA0) || ($c >= 0xE0))  $i++;   // advance a double-byte char
+                               if (($c >= 0x80 && $c < 0xA0) || ($c >= 0xE0))  $i+=$d; // advance a double-byte char
                        }
                        else    {
-                               if ($c >= 0x80) $i++;   // advance a double-byte char
+                               if ($c >= 0x80) $i+=$d; // advance a double-byte char
                        }
 
                        $n++;
                }
                if (!$str{$i})  return false; // offset beyond string length
 
+               if ($pos < 0)   $i++;   // correct offset
+
                return $i;
        }