/**
* Render the completed PDF to a string.
* If $newSegmentOnly is true, then only appended part of PDF is returned.
*
* @param boolean $newSegmentOnly
* @return string
*/
public function render($newSegmentOnly = false)
{
$this->_dumpPages();
// Check, that PDF file was modified
// File is always modified by _dumpPages() now, but future implementations may eliminate this.
if (!$this->_objFactory->isModified()) {
if ($newSegmentOnly) {
return '';
} else {
return $this->_trailer->getPDFString();
}
}
// offset (from a start of PDF file) of new PDF file segment
$segmentOffset = $this->_trailer->getPDFLength();
// new PDF file segment itself
$pdfSegment = '';
// Last Object number in a list of free objects
$lastFreeObject = $this->_trailer->getLastFreeObject();
// Array of cross-reference table subsections
$xrefTable = array();
// Object numbers of first objects in each subsection
$xrefSectionStartNums = array();
// Last cross-reference table subsection
$xrefSection = array();
// Dummy initialization of the first element (specail case - header of linked list of free objects).
$xrefSection[] = 0;
$xrefSectionStartNums[] = 0;
// Object number of last processed PDF object.
// Used to manage cross-reference subsections.
// Initialized by zero (specail case - header of linked list of free objects).
$lastObjNum = 0;
// Iterate objects to create new reference table
foreach ($this->_objFactory->listModifiedObjects() as $updateInfo) {
$objNum = $updateInfo->getObjNum();
if ($objNum - $lastObjNum != 1) {
// Save cross-reference table subsection and start new one
$xrefTable[] = $xrefSection;
$xrefSection = array();
$xrefSectionStartNums[] = $objNum;
}
if ($updateInfo->isFree()) {
// Free object cross-reference table entry
$xrefSection[] = sprintf("%010d %05d f \n", $lastFreeObject, $updateInfo->getGenNum());
$lastFreeObject = $objNum;
} else {
// In-use object cross-reference table entry
$xrefSection[] = sprintf("%010d %05d n \n", $segmentOffset + strlen($pdfSegment), $updateInfo->getGenNum());
$pdfSegment .= $updateInfo->getObjectDump();
}
$lastObjNum = $objNum;
}
// Save last cross-reference table subsection
$xrefTable[] = $xrefSection;
// Modify first entry (specail case - header of linked list of free objects).
$xrefTable[0][0] = sprintf("%010d 65535 f \n", $lastFreeObject);
$xrefTableStr = "xref\n";
foreach ($xrefTable as $sectId => $xrefSection) {
$xrefTableStr .= sprintf("%d %d \n", $xrefSectionStartNums[$sectId], count($xrefSection));
foreach ($xrefSection as $xrefTableEntry) {
$xrefTableStr .= $xrefTableEntry;
}
}
$xrefStartOffset = $segmentOffset + strlen($pdfSegment);
$this->_trailer->Size->value = $this->_objFactory->getObjectCount();
$pdfSegment .= $xrefTableStr . $this->_trailer->toString() . "startxref\n" . $xrefStartOffset . "\n" . "%%EOF\n";
if ($newSegmentOnly) {
return $pdfSegment;
} else {
return $this->_trailer->getPDFString() . $pdfSegment;
}
}
