interchange/import_xmp_from_pdf

<?php

/* $Id: import_xmp_from_pdf.php,v 1.2 2009/06/03 16:59:11 rp Exp $

 * 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 7

 * Required data: PDF document with XMP metadata

 */

/* This is where the data files are. Adjust as necessary. */

$searchpath = "../input";

$outfile = "";

$title = "Import XMP from PDF";

$pdffile = "PDFlib-real-world.pdf";

try {

    $p = new PDFlib();

    $p->set_parameter("SearchPath", $searchpath);

    /* This means we must check return values of load_font() etc. */

    $p->set_parameter("errorpolicy", "return");

    $p->set_parameter("textformat", "utf8");

   

    /* 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());

        /* Dummy page size; will be adjusted later */

        $p->begin_page_ext(10, 10, "");

        /* 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) {

        die("PDFlib exception occurred:\n".

            "[" . $e->get_errnum() . "] " . $e->get_apiname() .

            ": " . $e->get_errmsg() . "\n");

    } catch (Exception $e) {

        die($e->getMessage());

    }

$p=0;

?>