CODEWITHSUNDEEP
phppdfsearchfpdf
Photon
Photon

Reputation: 355

Search PDF for strings and get their position on the page

I would like to add nameddests to locations of an existing PDF which are specified by some string (say: put a nameddest on the first occurence of the string "Chapter 1"). Then I would like to be able to jump to those nameddests using JS events.

What I have achieved so far using PHP and FPDF/FPDI: I can load an existing PDF using FPDI and add nameddests to arbitrary positions using a slightly modified version of [1]. I can then embed the PDF in an iframe and navigate to the nameddests using, for example, JS buttons.

However, so far I need to find out the positions of the nameddests by hand. How can I search the PDF for strings and get the page numbers and positions of the search results such that I can add nameddests there?

[1] http://www.fpdf.org/en/script/script99.php

Upvotes: 0

Views: 2876

Answers (1)

Jan Slabon
Jan Slabon

Reputation: 5058

It is impossible to analyse the content of a PDF document with FPDI.

We (Setasign - author of FPDI and PDF_NamedDestinations) have a product (not free) available which allows you to do handle this task: The SetaPDF-Extractor component.

A simple POC of your project could look like:

<?php
// load and register the autoload function
require_once('library/SetaPDF/Autoload.php');

$writer = new SetaPDF_Core_Writer_Http('result.pdf', true);
$document = SetaPDF_Core_Document::loadByFilename('file/with/chapters.pdf', $writer);

$extractor = new SetaPDF_Extractor($document);

// define the word strategy
$strategy = new SetaPDF_Extractor_Strategy_Word();
$extractor->setStrategy($strategy);

// get the pages helper
$pages = $document->getCatalog()->getPages();

// get access to the named destination tree
$names = $document
    ->getCatalog()
    ->getNames()
    ->getTree(SetaPDF_Core_Document_Catalog_Names::DESTS, true);

for ($pageNo = 1; $pageNo <= $pages->count(); $pageNo++) {
    /**
     * @var SetaPDF_Extractor_Result_Word[] $words
     */
    $words = $extractor->getResultByPageNumber($pageNo);

    // iterate over all found words and search for "Chapter" followed by a numeric string...
    foreach ($words AS $word) {
        $string = $word->getString();
        if ($string === 'Chapter') {
            $chapter = $word;
            continue;
        }

        if (null === $chapter) {
            continue;
        }

        // is the next word a numeric string
        if (is_numeric($word->getString())) {
            // get the coordinates of the word
            $bounds = $word->getBounds()[0];
            // create a destination
            $destination = SetaPDF_Core_Document_Destination::createByPageNo(
                $document,
                $pageNo,
                SetaPDF_Core_Document_Destination::FIT_MODE_FIT_BH,
                $bounds->getUl()->getY()
            );

            // create a name (shall be unique)
            $name = strtolower($chapter . $word->getString());
            try {
                // add the named destination to the name tree
                $names->add($name, $destination->getPdfValue());
            } catch (SetaPDF_Core_DataStructure_Tree_KeyAlreadyExistsException $e) {
                // handle this exception
            }
        }

        $chapter = null;
    }
}

// save and finish the resulting document
$document->save()->finish();

You can then access the named destinations through the URL this way (the viewer application and browser plugin need to support this):

http://www.example.com/script.php#chapter1
http://www.example.com/script.php#chapter2
http://www.example.com/script.php#chapter10
...

Upvotes: 1

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