File: /home/nexper/public_html/crm/modules/AOD_Index/PdfParser.php
<?php
/**
* @file
* Class PdfParser
*
* @author : Sebastien MALOT <sebastien@malot.fr>
* @date : 2013-08-08
*
* References :
* - http://www.mactech.com/articles/mactech/Vol.15/15.09/PDFIntro/index.html
* - http://framework.zend.com/issues/secure/attachment/12512/Pdf.php
* - http://www.php.net/manual/en/ref.pdf.php#74211
*/
class PdfParser
{
/**
* Parse PDF file
*
* @param string $filename
* @return string
*/
public static function parseFile($filename)
{
$content = file_get_contents($filename);
return self::extractText($content);
}
/**
* Parse PDF content
*
* @param string $content
* @return string
*/
public static function parseContent($content)
{
return self::extractText($content);
}
/**
* Convert a PDF into text.
*
* @param string $filename The filename to extract the data from.
* @return string The extracted text from the PDF
*/
protected static function extractText($data)
{
/**
* Split apart the PDF document into sections. We will address each
* section separately.
*/
$a_obj = self::getDataArray($data, 'obj', 'endobj');
$j = 0;
$a_chunks = array();
/**
* Attempt to extract each part of the PDF document into a 'filter'
* element and a 'data' element. This can then be used to decode the
* data.
*/
foreach ($a_obj as $obj) {
$a_filter = self::getDataArray($obj, '<<', '>>');
if (is_array($a_filter) && isset($a_filter[0])) {
$a_chunks[$j]['filter'] = $a_filter[0];
$a_data = self::getDataArray($obj, 'stream', 'endstream');
if (is_array($a_data) && isset($a_data[0])) {
$a_chunks[$j]['data'] = trim(substr($a_data[0], strlen('stream'), strlen($a_data[0]) - strlen('stream') - strlen('endstream')));
}
$j++;
}
}
$result_data = null;
// decode the chunks
foreach ($a_chunks as $chunk) {
// Look at each chunk decide if we can decode it by looking at the contents of the filter
if (isset($chunk['data'])) {
// look at the filter to find out which encoding has been used
if (strpos($chunk['filter'], 'FlateDecode') !== false) {
// Use gzuncompress but suppress error messages.
$data =@ gzuncompress($chunk['data']);
} else {
$data = $chunk['data'];
}
if (trim($data) != '') {
// If we got data then attempt to extract it.
$result_data .= ' ' . self::extractTextElements($data);
}
}
}
/**
* Make sure we don't have large blocks of white space before and after
* our string. Also extract alphanumerical information to reduce
* redundant data.
*/
if (trim($result_data) == '') {
return null;
} else {
// Optimize hyphened words
$result_data = preg_replace('/\s*-[\r\n]+\s*/', '', $result_data);
$result_data = preg_replace('/\s+/', ' ', $result_data);
return $result_data;
}
}
protected static function extractTextElements($content)
{
if (strpos($content, '/CIDInit') === 0) {
return '';
}
$text = '';
$lines = explode("\n", $content);
foreach ($lines as $line) {
$line = trim($line);
$matches = array();
// Parse each lines to extract command and operator values
if (preg_match('/^(?<command>.*[\)\] ])(?<operator>[a-z]+[\*]?)$/i', $line, $matches)) {
$command = trim($matches['command']);
// Convert octal encoding
$found_octal_values = array();
preg_match_all('/\\\\([0-9]{3})/', $command, $found_octal_values);
foreach($found_octal_values[0] as $value) {
$octal = substr($value, 1);
if (intval($octal) < 40) {
// Skips non printable chars
$command = str_replace($value, '', $command);
} else {
$command = str_replace($value, chr(octdec($octal)), $command);
}
}
// Removes encoded new lines, tabs, ...
$command = preg_replace('/\\\\[\r\n]/', '', $command);
$command = preg_replace('/\\\\[rnftb ]/', ' ', $command);
// Force UTF-8 charset
$encoding = mb_detect_encoding($command, array('ASCII', 'UTF-8', 'Windows-1252', 'ISO-8859-1'));
if (strtoupper($encoding) != 'UTF-8') {
if ($decoded = @iconv('CP1252', 'UTF-8//TRANSLIT//IGNORE', $command)) {
$command = $decoded;
}
}
// Removes leading spaces
$operator = trim($matches['operator']);
} else {
$command = $line;
$operator = '';
}
// Handle main operators
switch ($operator) {
// Set character spacing.
case 'Tc':
break;
// Move text current point.
case 'Td':
$values = explode(' ', $command);
$y = array_pop($values);
$x = array_pop($values);
if ($x > 0) {
$text .= ' ';
}
if ($y < 0) {
$text .= ' ';
}
break;
// Move text current point and set leading.
case 'TD':
$values = explode(' ', $command);
$y = array_pop($values);
if ($y < 0) {
$text .= "\n";
}
break;
// Set font name and size.
case 'Tf':
$text.= ' ';
break;
// Display text, allowing individual character positioning
case 'TJ':
$start = mb_strpos($command, '[', null, 'UTF-8') + 1;
$end = mb_strrpos($command, ']', null, 'UTF-8');
$text.= self::parseTextCommand(mb_substr($command, $start, $end - $start, 'UTF-8'));
break;
// Display text.
case 'Tj':
$start = mb_strpos($command, '(', null, 'UTF-8') + 1;
$end = mb_strrpos($command, ')', null, 'UTF-8');
$text.= mb_substr($command, $start, $end - $start, 'UTF-8'); // Removes round brackets
break;
// Set leading.
case 'TL':
// Set text matrix.
case 'Tm':
// $text.= ' ';
break;
// Set text rendering mode.
case 'Tr':
break;
// Set super/subscripting text rise.
case 'Ts':
break;
// Set text spacing.
case 'Tw':
break;
// Set horizontal scaling.
case 'Tz':
break;
// Move to start of next line.
case 'T*':
$text.= "\n";
break;
// Internal use
case 'g':
case 'gs':
case 're':
case 'f':
// Begin text
case 'BT':
// End text
case 'ET':
break;
case '':
break;
default:
}
}
$text = str_replace(array('\\(', '\\)'), array('(', ')'), $text);
return $text;
}
/**
* Strip out the text from a small chunk of data.
*
* @param string $text
* @param int $font_size Currently not used
*
* @return string
*/
protected static function parseTextCommand($text, $font_size = 0) {
$result = '';
$cur_start_pos = 0;
while (($cur_start_text = mb_strpos($text, '(', $cur_start_pos, 'UTF-8')) !== false) {
// New text element found
if ($cur_start_text - $cur_start_pos > 8) {
$spacing = ' ';
} else {
$spacing_size = mb_substr($text, $cur_start_pos, $cur_start_text - $cur_start_pos, 'UTF-8');
if ($spacing_size < -50) {
$spacing = ' ';
} else {
$spacing = '';
}
}
$cur_start_text++;
$start_search_end = $cur_start_text;
while (($cur_start_pos = mb_strpos($text, ')', $start_search_end, 'UTF-8')) !== false) {
if (mb_substr($text, $cur_start_pos - 1, 1, 'UTF-8') != '\\') {
break;
}
$start_search_end = $cur_start_pos + 1;
}
// something wrong happened
if ($cur_start_pos === false) {
break;
}
// Add to result
$result .= $spacing . mb_substr($text, $cur_start_text, $cur_start_pos - $cur_start_text, 'UTF-8');
$cur_start_pos++;
}
return $result;
}
/**
* Convert a section of data into an array, separated by the start and end words.
*
* @param string $data The data.
* @param string $start_word The start of each section of data.
* @param string $end_word The end of each section of data.
* @return array The array of data.
*/
protected static function getDataArray($data, $start_word, $end_word)
{
$start = 0;
$end = 0;
$a_results = array();
while ($start !== false && $end !== false) {
$start = strpos($data, $start_word, $end);
$end = strpos($data, $end_word, $start);
if ($end !== false && $start !== false) {
// data is between start and end
$a_results[] = substr($data, $start, $end - $start + strlen($end_word));
}
}
return $a_results;
}
}