class File in Bibliography Module 6.2

Class File Class to read MARC records from file(s)

Hierarchy

• class \File

File

modules/marcParse/php-marc.php, line 76

class File {

  /**
   * ========== VARIABLE DECLARATIONS ==========
   */

  /**
   * Array containing raw records
   * @var array
   */
  var $raw;

  /**
   * Array of warnings
   * @var array
   */
  var $warn;

  /**
   * Current position in the array of records
   * @var integer
   */
  var $pointer;

  /**
   * ========== ERROR FUNCTIONS ==========
   */

  /**
   * Croaking function
   *
   * Similar to Perl's croak function, which ends parsing and raises an
   * user error with a descriptive message.
   * @param string The message to display
   */
  function _croak($msg) {
    trigger_error($msg, E_USER_ERROR);
  }

  /**
   * Fuction to issue warnings
   *
   * Warnings will not be displayed unless explicitly accessed, but all
   * warnings issued during parse will be stored
   * @param string Warning
   * @return string Last added warning
   */
  function _warn($msg) {
    $this->warn[] = $msg;
    return $msg;
  }

  /**
   * Get warning(s)
   *
   * Get either all warnings or a specific warning ID
   * @param integer ID of the warning
   * @return array|string Return either Array of all warnings or specific warning
   */
  function warnings($id = "") {
    if (!$id) {
      return $this->warn;
    }
    else {
      if (array_key_exists($id, $this->warn)) {
        return $this->warn[$id];
      }
      else {
        return "Invalid warning ID: {$id}";
      }
    }
  }

  /**
   * ========== PROCESSING FUNCTIONS ==========
   */

  /**
   * Return the next raw MARC record
   *
   * Returns th nexts raw MARC record from the read file, unless all
   * records already have been read.
   * @return string|false Either a raw record or False
   */
  function _next() {

    /**
     * Exit if we are at the end of the file
     */
    if ($this->pointer >= count($this->raw)) {
      return FALSE;
    }

    /**
     * Read next line
     */
    $usmarc = $this->raw[$this->pointer++];

    // remove illegal stuff that sometimes occurs between records
    // preg_replace does not know what to do with \x00, thus omitted.
    $usmarc = preg_replace("/^[\n\r]+/", "", $usmarc);

    /**
     * Record validation
     */
    if (strlen($usmarc) < 5) {
      $this
        ->_warn("Couldn't find record length");
    }
    $reclen = substr($usmarc, 0, 5);
    if (preg_match("/^\\d{5}\$/", $reclen) || $reclen != strlen($usmarc)) {
      $this
        ->_warn("Invalid record length \"{$reclen}\"");
    }
    return $usmarc;
  }

  /**
   * Read in MARC record file
   *
   * This function will read in MARC record files that either
   * contain a single MARC record, or numerous records.
   * @param string Name of the file
   * @return string Returns warning if issued during read
   */
  function file($in) {
    if (file_exists($in)) {
      $input = file($in);
      $recs = explode(END_OF_RECORD, join("", $input));

      // Append END_OF_RECORD as we lost it when splitting
      // Last is not record, as it is empty because every record ends
      // with END_OF_RECORD.
      for ($i = 0; $i < count($recs) - 1; $i++) {
        $this->raw[] = $recs[$i] . END_OF_RECORD;
      }
      $this->pointer = 0;
    }
    else {
      return $this
        ->_warn("Invalid input file: {$i}");
    }
  }

  /**
   * Return next Record-object
   *
   * Decode the next raw MARC record and return
   * @return Record A Record object
   */
  function next() {
    if ($raw = $this
      ->_next()) {
      return $this
        ->decode($raw);
    }
    else {
      return FALSE;
    }
  }

  /**
   * Decode a given raw MARC record
   *
   * "Port" of Andy Lesters MARC::File::USMARC->decode() function into PHP. Ideas and
   * "rules" have been used from USMARC::decode().
   *
   * @param string Raw MARC record
   * @return Record Decoded MARC Record object
   */
  function decode($text) {
    if (!preg_match("/^\\d{5}/", $text, $matches)) {
      $this
        ->_croak('Record length "' . substr($text, 0, 5) . '" is not numeric');
    }
    $marc = new Record();

    // Store record length
    $reclen = $matches[0];
    if ($reclen != strlen($text)) {
      $this
        ->_croak("Invalid record length: Leader says {$reclen} bytes, but it's actually " . strlen($text));
    }
    if (substr($text, -1, 1) != END_OF_RECORD) {
      $this
        ->_croak("Invalid record terminator");
    }

    // Store leader
    $marc
      ->leader(substr($text, 0, LEADER_LEN));

    // bytes 12 - 16 of leader give offset to the body of the record
    $data_start = 0 + substr($text, 12, 5);

    // immediately after the leader comes the directory (no separator)
    $dir = substr($text, LEADER_LEN, $data_start - LEADER_LEN - 1);

    // -1 to allow for \x1e at end of directory
    // character after the directory must be \x1e
    if (substr($text, $data_start - 1, 1) != END_OF_FIELD) {
      $this
        ->_croak("No directory found");
    }

    // All directory entries 12 bytes long, so length % 12 must be 0
    if (strlen($dir) % DIRECTORY_ENTRY_LEN != 0) {
      $this
        ->_croak("Invalid directory length");
    }

    // go through all the fields
    $nfields = strlen($dir) / DIRECTORY_ENTRY_LEN;
    for ($n = 0; $n < $nfields; $n++) {

      // As pack returns to key 1, leave place 0 in list empty
      list(, $tagno) = unpack("A3", substr($dir, $n * DIRECTORY_ENTRY_LEN, DIRECTORY_ENTRY_LEN));
      list(, $len) = unpack("A3/A4", substr($dir, $n * DIRECTORY_ENTRY_LEN, DIRECTORY_ENTRY_LEN));
      list(, $offset) = unpack("A3/A4/A5", substr($dir, $n * DIRECTORY_ENTRY_LEN, DIRECTORY_ENTRY_LEN));

      // Check directory validity
      if (!preg_match("/^[0-9A-Za-z]{3}\$/", $tagno)) {
        $this
          ->_croak("Invalid tag in directory: \"{$tagno}\"");
      }
      if (!preg_match("/^\\d{4}\$/", $len)) {
        $this
          ->_croak("Invalid length in directory, tag {$tagno}: \"{$len}\"");
      }
      if (!preg_match("/^\\d{5}\$/", $offset)) {
        $this
          ->_croak("Invalid offset in directory, tag {$tagno}: \"{$offset}\"");
      }
      if ($offset + $len > $reclen) {
        $this
          ->_croak("Directory entry runs off the end of the record tag {$tagno}");
      }
      $tagdata = substr($text, $data_start + $offset, $len);
      if (substr($tagdata, -1, 1) == END_OF_FIELD) {

        # get rid of the end-of-tag character
        $tagdata = substr($tagdata, 0, -1);
        --$len;
      }
      else {
        $this
          ->_croak("field does not end in end of field character in tag {$tagno}");
      }
      if (preg_match("/^\\d+\$/", $tagno) && $tagno < 10) {
        $marc
          ->append_fields(new Field($tagno, $tagdata));
      }
      else {
        $subfields = explode(SUBFIELD_INDICATOR, $tagdata);
        $indicators = array_shift($subfields);
        if (strlen($indicators) > 2 || strlen($indicators) == 0) {
          $this
            ->_warn("Invalid indicators \"{$indicators}\" forced to blanks for tag {$tagno}\n");
          list($ind1, $ind2) = array(
            " ",
            " ",
          );
        }
        else {
          $ind1 = substr($indicators, 0, 1);
          $ind2 = substr($indicators, 1, 1);
        }

        // Split the subfield data into subfield name and data pairs
        $subfield_data = array();
        foreach ($subfields as $subfield) {
          if (strlen($subfield) > 0) {
            $subfield_data[substr($subfield, 0, 1)][] = substr($subfield, 1);
          }
          else {
            $this
              ->_warn("Entirely empty subfield found in tag {$tagno}");
          }
        }
        if (!isset($subfield_data)) {
          $this
            ->_warn("No subfield data found {$location} for tag {$tagno}");
        }
        $marc
          ->append_fields(new Field($tagno, $ind1, $ind2, $subfield_data));
      }
    }
    return $marc;
  }

  /**
   * Get the number of records available in this Record
   * @return int The number of records
   */
  function num_records() {
    return count($this->raw);
  }

}

Members

Name	Modifiers	Type	Description	Overrides
File::$pointer		property	Current position in the array of records
File::$raw		property	Array containing raw records
File::$warn		property	Array of warnings
File::decode		function	Decode a given raw MARC record
File::file		function	Read in MARC record file
File::next		function	Return next Record-object
File::num_records		function	Get the number of records available in this Record
File::warnings		function	Get warning(s)
File::_croak		function	Croaking function
File::_next		function	Return the next raw MARC record
File::_warn		function	Fuction to issue warnings