What is it?

This package contains a set of code examples(bare minimum) for signing existing PDF documents. The aim is to provide features similar to Hellosign's platform. The examples cover different aspects, such as:

• Identifying where to sign the document with an administrator's input.
• Enabling users to sign documents at designated positions.
• Adding signatures images to positions specified by users.
• Adding footers to all pages of a PDF.
• Combining multiple PDF documents.
• Deleting specific pages from an existing PDF.

Overall, this package provides a comprehensive solution for signing PDF documents and related functionalities.

The examples in this package use PHP, but similar techniques can be applied to other programming languages with PDF manipulation libraries.

Dependencies

• PHP (Laravel is optional but helpful for testing)
• propa/tcpdi: loads existing PDF files (dependent on tcpdf with full functionality)
• tcpdf: loaded by propa/tcpdi
• spatie/pdf-to-image: converts PDFs to images
• Jquery Droppable

Overall, these dependencies provide the necessary tools to load, manipulate, and convert PDF files in a PHP environment.

Features

Identifying where to sign the document with an administrator's input

Code

    // load the pdf
    $original_filename = 'filename';
    $store_in = public_path("pdf-images/{$original_filename}.png");
    $pdf = new \Spatie\PdfToImage\Pdf("{$original_filename}.pdf");
    $pdf->saveImage($store_in);

    return view('welcome', [
        'file_path' => "pdf-images/{$original_filename}.png"
    ]);
    
    
    // send the pdf
    $x = $request->x;
    $y = $request->y;
    session(['x' => $x > 0 ? $x : 0, 'y' => $y > 0 ? $y : 0]);
    
    return redirect()->to('/user');

Explaination

• inside routes/web.php the route /admin is meant for this purpose.
• what we do there is we change pdf to image and sent the image to the welcome.blade.php.
• then on the image we use query to drag and drop desired position.
• then we submit the pdf to store the position of x and y in session for later use.

Enabling users to sign documents at designated positions

Code

    // load for user
    $original_filename = 'MAS Screening - bin-3';

    return view('welcome-user', [
        'file_path' => "pdf-images/{$original_filename}.png",
        'x' => session('x'),
        'y' => session('y'),
    ]);

What it does

• after admin has marked the position from /admin route
• the x and y position is stored and session and sent it to the user menu with /user route along with the pdf file itself
• only then in frontend we add the html Click here to signature html element on the provided x, y position

Adding signatures images to positions specified by users

Code

    $x = floatval(session('x'));
    $y = session('y');
    /** y axis has a margin but it's not a constant margin instead it's more like 0.2% of each position */
    $y = floatval($y) - ($y * .2);

    $pdf = new TCPDI('L', 'px', PDF_PAGE_FORMAT, true, 'UTF-8', false);

    // Add a page from a PDF by file path.
    $pdf->setPrintHeader(false);
    $pdf->setPrintFooter(false);
    $pdf->AddPage();

    $pdf->setSourceFile('/path/to/file');
    $idx = $pdf->importPage(1);
    $pdf->useTemplate($idx);

    $pdf->Image('myint_oo_signature_62f4c002732ec.png', $x, $y, '', '', '', '', '', false, 300);

    $pdf->Output('WorksheetTest.pdf', 'I');

What it does

• after user has added their signature, the position won't be change because user should not normally has the ability to change the position
• in routes/web.php route /sign we use tcpdi method to load the existing pdf and tcpdf Image method to add the signature image.

Adding footers to all pages of a PDF.

Code

    $pdf = new TCPDIExtension('L', 'px', PDF_PAGE_FORMAT, true, 'UTF-8', false);
    $pdf->setPrintHeader(false);
    $pdf->setPrintFooter(true);
    $pdf->AddPage();
    $pdf->setSourceFile('/path/to/file');
    $idx = $pdf->importPage(1);
    $pdf->useTemplate($idx);

    // set default monospaced font
    $pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);
    $pdf->Output('WorksheetTest.pdf', 'I');

What it does

to customize the footer we need to extends the TCPDI and then overwrites Footer method.

Combining multiple PDF documents

Code

    $pdf = new TCPDIExtension('L', 'pt', PDF_PAGE_FORMAT, true, 'UTF-8', false);
    $pdf->setPrintHeader(false);
    $pdf->setPrintFooter(false);
    $pdf->AddPage();
    $pdf->setSourceFile('/path/to/file');
    $idx = $pdf->importPage(1);
    $pdf->useTemplate($idx);

    // set default monospaced font
    $pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);

    $pdf->AddPage();
    $pdf->setSourceFile('/path/to/another/file');
    $idx = $pdf->importPage(1);
    $pdf->useTemplate($idx);
    $pdf->Output('WorksheetTest.pdf', 'I');

Deleting specific pages from an existing PDF.

Code

    $pdf = new TCPDIExtension('L', 'pt', PDF_PAGE_FORMAT, true, 'UTF-8', false);
    
    $pdf_data = file_get_contents('WorksheetTest.pdf'); // Simulate only having raw data available.
    $page_count = $pdf->setSourceData($pdf_data);

    // loads all pages from the source document
    for ($i = 1; $i <= $page_count; $i++) {
        $tplidx = $pdf->importPage($i);
        $pdf->setPrintHeader(false);
        $pdf->setPrintFooter(false);
        $pdf->AddPage();
        $pdf->useTemplate($tplidx);
    }
    
    $last_page = $pdf->getPage();
    $pdf->deletePage($last_page);

    $pdf->Output('WorksheetTest.pdf', 'I');