AbstractHeader.php

Go to the documentation of this file.

<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

//@require 'Swift/Mime/Header.php';
//@require 'Swift/Mime/HeaderEncoder.php';
//@require 'Swift/RfcComplianceException.php';

abstract class Swift_Mime_Headers_AbstractHeader implements Swift_Mime_Header
{
  
  private $_specials = array();
  
  private $_grammar = array();
  
  private $_name;
  
  private $_encoder;
  
  private $_lineLength = 78;
  
  private $_lang;
  
  private $_charset = 'utf-8';
  
  private $_cachedValue = null;
  
  public function setCharset($charset)
  {
    $this->clearCachedValueIf($charset != $this->_charset);
    $this->_charset = $charset;
    if (isset($this->_encoder))
    {
      $this->_encoder->charsetChanged($charset);
    }
  }
  
  public function getCharset()
  {
    return $this->_charset;
  }
  
  public function setLanguage($lang)
  {
    $this->clearCachedValueIf($this->_lang != $lang);
    $this->_lang = $lang;
  }
  
  public function getLanguage()
  {
    return $this->_lang;
  }
  
  public function setEncoder(Swift_Mime_HeaderEncoder $encoder)
  {
    $this->_encoder = $encoder;
    $this->setCachedValue(null);
  }
  
  public function getEncoder()
  {
    return $this->_encoder;
  }
  
  public function getFieldName()
  {
    return $this->_name;
  }
  
  public function setMaxLineLength($lineLength)
  {
    $this->clearCachedValueIf($this->_lineLength != $lineLength);
    $this->_lineLength = $lineLength;
  }
  
  public function getMaxLineLength()
  {
    return $this->_lineLength;
  }
  
  public function toString()
  {
    return $this->_tokensToString($this->toTokens());
  }
  
  public function __toString()
  {
    return $this->toString();
  }
  
  // -- Points of extension
  
  protected function setFieldName($name)
  {
    $this->_name = $name;
  }
  
  protected function initializeGrammar()
  {
    $this->_specials = array(
      '(', ')', '<', '>', '[', ']',
      ':', ';', '@', ',', '.', '"'
      );
    
    /*** Refer to RFC 2822 for ABNF grammar ***/
    
    //All basic building blocks
    $this->_grammar['NO-WS-CTL'] = '[\x01-\x08\x0B\x0C\x0E-\x19\x7F]';
    $this->_grammar['WSP'] = '[ \t]';
    $this->_grammar['CRLF'] = '(?:\r\n)';
    $this->_grammar['FWS'] = '(?:(?:' . $this->_grammar['WSP'] . '*' .
        $this->_grammar['CRLF'] . ')?' . $this->_grammar['WSP'] . ')';
    $this->_grammar['text'] = '[\x00-\x08\x0B\x0C\x0E-\x7F]';
    $this->_grammar['quoted-pair'] = '(?:\\\\' . $this->_grammar['text'] . ')';
    $this->_grammar['ctext'] = '(?:' . $this->_grammar['NO-WS-CTL'] .
        '|[\x21-\x27\x2A-\x5B\x5D-\x7E])';
    //Uses recursive PCRE (?1) -- could be a weak point??
    $this->_grammar['ccontent'] = '(?:' . $this->_grammar['ctext'] . '|' .
        $this->_grammar['quoted-pair'] . '|(?1))';
    $this->_grammar['comment'] = '(\((?:' . $this->_grammar['FWS'] . '|' .
        $this->_grammar['ccontent']. ')*' . $this->_grammar['FWS'] . '?\))';
    $this->_grammar['CFWS'] = '(?:(?:' . $this->_grammar['FWS'] . '?' .
        $this->_grammar['comment'] . ')*(?:(?:' . $this->_grammar['FWS'] . '?' .
        $this->_grammar['comment'] . ')|' . $this->_grammar['FWS'] . '))';
    $this->_grammar['qtext'] = '(?:' . $this->_grammar['NO-WS-CTL'] .
        '|[\x21\x23-\x5B\x5D-\x7E])';
    $this->_grammar['qcontent'] = '(?:' . $this->_grammar['qtext'] . '|' .
        $this->_grammar['quoted-pair'] . ')';
    $this->_grammar['quoted-string'] = '(?:' . $this->_grammar['CFWS'] . '?"' .
        '(' . $this->_grammar['FWS'] . '?' . $this->_grammar['qcontent'] . ')*' .
        $this->_grammar['FWS'] . '?"' . $this->_grammar['CFWS'] . '?)';
    $this->_grammar['atext'] = '[a-zA-Z0-9!#\$%&\'\*\+\-\/=\?\^_`\{\}\|~]';
    $this->_grammar['atom'] = '(?:' . $this->_grammar['CFWS'] . '?' .
        $this->_grammar['atext'] . '+' . $this->_grammar['CFWS'] . '?)';
    $this->_grammar['dot-atom-text'] = '(?:' . $this->_grammar['atext'] . '+' .
        '(\.' . $this->_grammar['atext'] . '+)*)';
    $this->_grammar['dot-atom'] = '(?:' . $this->_grammar['CFWS'] . '?' .
        $this->_grammar['dot-atom-text'] . '+' . $this->_grammar['CFWS'] . '?)';
    $this->_grammar['word'] = '(?:' . $this->_grammar['atom'] . '|' .
        $this->_grammar['quoted-string'] . ')';
    $this->_grammar['phrase'] = '(?:' . $this->_grammar['word'] . '+?)';
    $this->_grammar['no-fold-quote'] = '(?:"(?:' . $this->_grammar['qtext'] .
        '|' . $this->_grammar['quoted-pair'] . ')*")';
    $this->_grammar['dtext'] = '(?:' . $this->_grammar['NO-WS-CTL'] .
        '|[\x21-\x5A\x5E-\x7E])';
    $this->_grammar['no-fold-literal'] = '(?:\[(?:' . $this->_grammar['dtext'] .
        '|' . $this->_grammar['quoted-pair'] . ')*\])';
    
    //Message IDs
    $this->_grammar['id-left'] = '(?:' . $this->_grammar['dot-atom-text'] . '|' .
        $this->_grammar['no-fold-quote'] . ')';
    $this->_grammar['id-right'] = '(?:' . $this->_grammar['dot-atom-text'] . '|' .
        $this->_grammar['no-fold-literal'] . ')';
    
    //Addresses, mailboxes and paths
    $this->_grammar['local-part'] = '(?:' . $this->_grammar['dot-atom'] . '|' .
        $this->_grammar['quoted-string'] . ')';
    $this->_grammar['dcontent'] = '(?:' . $this->_grammar['dtext'] . '|' .
        $this->_grammar['quoted-pair'] . ')';
    $this->_grammar['domain-literal'] = '(?:' . $this->_grammar['CFWS'] . '?\[(' .
        $this->_grammar['FWS'] . '?' . $this->_grammar['dcontent'] . ')*?' .
        $this->_grammar['FWS'] . '?\]' . $this->_grammar['CFWS'] . '?)';
    $this->_grammar['domain'] = '(?:' . $this->_grammar['dot-atom'] . '|' .
        $this->_grammar['domain-literal'] . ')';
    $this->_grammar['addr-spec'] = '(?:' . $this->_grammar['local-part'] . '@' .
        $this->_grammar['domain'] . ')';
  }
  
  protected function getGrammar($name)
  {
    if (array_key_exists($name, $this->_grammar))
    {
      return $this->_grammar[$name];
    }
    else
    {
      throw new Swift_RfcComplianceException(
        "No such grammar '" . $name . "' defined."
        );
    }
  }
  
  protected function escapeSpecials($token, $include = array(),
    $exclude = array())
  {
    foreach (
      array_merge(array('\\'), array_diff($this->_specials, $exclude), $include) as $char)
    {
      $token = str_replace($char, '\\' . $char, $token);
    }
    return $token;
  }
  
  protected function createPhrase(Swift_Mime_Header $header, $string, $charset,
    Swift_Mime_HeaderEncoder $encoder = null, $shorten = false)
  {
    //Treat token as exactly what was given
    $phraseStr = $string;
    //If it's not valid
    if (!preg_match('/^' . $this->_grammar['phrase'] . '$/D', $phraseStr))
    {
      // .. but it is just ascii text, try escaping some characters
      // and make it a quoted-string
      if (preg_match('/^' . $this->_grammar['text'] . '*$/D', $phraseStr))
      {
        $phraseStr = $this->escapeSpecials(
          $phraseStr, array('"'), $this->_specials
          );
        $phraseStr = '"' . $phraseStr . '"';
      }
      else // ... otherwise it needs encoding
      {
        //Determine space remaining on line if first line
        if ($shorten)
        {
          $usedLength = strlen($header->getFieldName() . ': ');
        }
        else
        {
          $usedLength = 0;
        }
        $phraseStr = $this->encodeWords($header, $string, $usedLength);
      }
    }
    
    return $phraseStr;
  }
  
  protected function encodeWords(Swift_Mime_Header $header, $input,
    $usedLength = -1)
  {
    $value = '';
    
    $tokens = $this->getEncodableWordTokens($input);
    
    foreach ($tokens as $token)
    {
      //See RFC 2822, Sect 2.2 (really 2.2 ??)
      if ($this->tokenNeedsEncoding($token))
      {
        //Don't encode starting WSP
        $firstChar = substr($token, 0, 1);
        switch($firstChar)
        {
          case ' ':
          case "\t":
            $value .= $firstChar;
            $token = substr($token, 1);
        }
        
        if (-1 == $usedLength)
        {
          $usedLength = strlen($header->getFieldName() . ': ') + strlen($value);
        }
        $value .= $this->getTokenAsEncodedWord($token, $usedLength);
        
        $header->setMaxLineLength(76); //Forefully override
      }
      else
      {
        $value .= $token;
      }
    }
    
    return $value;
  }
  
  protected function tokenNeedsEncoding($token)
  {
    return preg_match('~[\x00-\x08\x10-\x19\x7F-\xFF\r\n]~', $token);
  }
  
  protected function getEncodableWordTokens($string)
  {
    $tokens = array();
    
    $encodedToken = '';
    //Split at all whitespace boundaries
    foreach (preg_split('~(?=[\t ])~', $string) as $token)
    {
      if ($this->tokenNeedsEncoding($token))
      {
        $encodedToken .= $token;
      }
      else
      {
        if (strlen($encodedToken) > 0)
        {
          $tokens[] = $encodedToken;
          $encodedToken = '';
        }
        $tokens[] = $token;
      }
    }
    if (strlen($encodedToken))
    {
      $tokens[] = $encodedToken;
    }
    
    return $tokens;
  }
  
  protected function getTokenAsEncodedWord($token, $firstLineOffset = 0)
  {
    //Adjust $firstLineOffset to account for space needed for syntax
    $charsetDecl = $this->_charset;
    if (isset($this->_lang))
    {
      $charsetDecl .= '*' . $this->_lang;
    }
    $encodingWrapperLength = strlen(
      '=?' . $charsetDecl . '?' . $this->_encoder->getName() . '??='
      );
    
    if ($firstLineOffset >= 75) //Does this logic need to be here?
    {
      $firstLineOffset = 0;
    }
    
    $encodedTextLines = explode("\r\n",
      $this->_encoder->encodeString(
        $token, $firstLineOffset, 75 - $encodingWrapperLength
        )
      );
    
    foreach ($encodedTextLines as $lineNum => $line)
    {
      $encodedTextLines[$lineNum] = '=?' . $charsetDecl .
        '?' . $this->_encoder->getName() .
        '?' . $line . '?=';
    }
    
    return implode("\r\n ", $encodedTextLines);
  }
  
  protected function generateTokenLines($token)
  {
    return preg_split('~(\r\n)~', $token, -1, PREG_SPLIT_DELIM_CAPTURE);
  }
  
  protected function setCachedValue($value)
  {
    $this->_cachedValue = $value;
  }
  
  protected function getCachedValue()
  {
    return $this->_cachedValue;
  }
  
  protected function clearCachedValueIf($condition)
  {
    if ($condition)
    {
      $this->setCachedValue(null);
    }
  }
  
  // -- Private methods
  
  protected function toTokens($string = null)
  {
    if (is_null($string))
    {
      $string = $this->getFieldBody();
    }
    
    $tokens = array();
    
    //Generate atoms; split at all invisible boundaries followed by WSP
    foreach (preg_split('~(?=[ \t])~', $string) as $token)
    {
      $tokens = array_merge($tokens, $this->generateTokenLines($token));
    }
    
    return $tokens;
  }
  
  private function _tokensToString(array $tokens)
  {
    $lineCount = 0;
    $headerLines = array();
    $headerLines[] = $this->_name . ': ';
    $currentLine =& $headerLines[$lineCount++];
    
    //Build all tokens back into compliant header
    foreach ($tokens as $i => $token)
    {
      //Line longer than specified maximum or token was just a new line
      if (("\r\n" == $token) ||
        ($i > 0 && strlen($currentLine . $token) > $this->_lineLength)
        && 0 < strlen($currentLine))
      {
        $headerLines[] = '';
        $currentLine =& $headerLines[$lineCount++];
      }
      
      //Append token to the line
      if ("\r\n" != $token)
      {
        $currentLine .= $token;
      }
    }
    
    //Implode with FWS (RFC 2822, 2.2.3)
    return implode("\r\n", $headerLines) . "\r\n";
  }
  
}