interchange/import_xmp_from_pdf
Retrieve the XMP metadata from an imported document and write all document-level XMP metadata to the output PDF.
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<?php
/*
* Import XMP from PDF:
* Retrieve the XMP metadata from an imported PDF document and write all
* document-level XMP metadata to the output PDF
*
* Maintain existing XMP metadata when processing documents: Read the XMP
* stream from the imported document with the pCOS path "/Root/Metadata",
* create a PVF file from the XMP and feed the document-level metadata to the
* output document.
*
* Required software: PDFlib+PDI/PPS 9
* Required data: PDF document with XMP metadata
*/
/* This is where the data files are. Adjust as necessary. */
$searchpath = dirname(__FILE__,3)."/input";
/* By default annotations are also imported. In some cases this
* requires the Noto fonts for creating annotation appearance streams.
* We therefore set the searchpath to also point to the font directory.
*/
$fontpath = dirname(__FILE__,3)."/resource/font";
$outfile = "";
$title = "Import XMP from PDF";
$pdffile = "PLOP-datasheet.pdf";
try {
$p = new PDFlib();
$p->set_option("searchpath={" . $searchpath . "}");
$p->set_option("searchpath={" . $fontpath . "}");
/* This means we must check return values of load_font() etc. */
$p->set_option("errorpolicy=return");
/* Open the input PDF */
$indoc = $p->open_pdi_document($pdffile, "");
if ($indoc == 0)
throw new Exception("Error: " + $p->get_errmsg());
/* Check if any document-level metadata exists in the input document */
$objtype = $p->pcos_get_string($indoc, "type:/Root/Metadata");
if ($objtype =="stream")
{
/* If document-level metadata exists retrieve it using the pCOS
* path "/Root/Metadata". (Similarly, you could retrieve any
* existing XMP metadata on page, font, or image level, etc. using
* the pCOS path "pages[...]/Metadata", "images[...]/Metadata",
* "fonts[...]/Metadata", etc.)
*/
$metadata = $p->pcos_get_stream($indoc, "", "/Root/Metadata");
}
if ($metadata != "")
{
/* If document-level metadata is available, store it in a
* PDFlib virtual file (PVF)
*/
$p->create_pvf("/pvf/metadata", $metadata, "");
/* Start the output document and copy the XMP metadata from the PVF
* to it
*/
if ($p->begin_document($outfile,
"metadata={filename=/pvf/metadata}") == 0)
throw new Exception("Error: " + $p->get_errmsg());
$p->delete_pvf("/pvf/metadata");
}
else
{
/* Start the output document without copying any metadata */
if ($p->begin_document($outfile, "") == 0)
throw new Exception("Error: " + $p->get_errmsg());
}
$p->set_info("Creator", "PDFlib Cookbook");
$p->set_info("Title", $title);
/* Retrieve the number of pages for the input document */
$endpage = $p->pcos_get_number($indoc, "length:pages");
/* Loop over all pages of the input document */
for ($pageno = 1; $pageno <= $endpage; $pageno++)
{
$page = $p->open_pdi_page($indoc, $pageno, "");
if ($page == 0)
throw new Exception("Error: " + $p->get_errmsg());
/* Page size may be adjusted by fit_pdi_page() */
$p->begin_page_ext(0, 0, "width=a4.width height=a4.height");
/* Place the imported page without performing
* any changes on the output page
*/
$p->fit_pdi_page($page, 0, 0, "adjustpage");
$p->end_page_ext("");
$p->close_pdi_page($page);
}
$p->end_document("");
$buf = $p->get_buffer();
$len = strlen($buf);
header("Content-type: application/pdf");
header("Content-Length: $len");
header("Content-Disposition: inline; filename=import_xmp_from_pdf.pdf");
print $buf;
} catch (PDFlibException $e) {
echo("PDFlib exception occurred:\n".
"[" . $e->get_errnum() . "] " . $e->get_apiname() .
": " . $e->get_errmsg() . "\n");
exit(1);
} catch (Throwable $e) {
echo("PHP exception occurred: " . $e->getMessage() . "\n");
exit(1);
}
$p = 0;
?>