Adding a custom header or footer in PHP with cURL

In this guide, we'll show you how to add custom headers or footers to a PDF using PHP and the cURL library.

We'll focus this guide on the header parameter, but know that the footer parameter works exactly the same way.

The header parameter is an object that accepts the following parameters:

• source: The source of the header. It can be a URL or a raw HTML document. You can also provide some variables that we'll explain at the bottom of this guide.
• height: The height of the header. By default, the height is in pixels, but you can also use mm, cm or in as units, like 10mm.
• start_at: The page number where the header should start. By default, the header will start at the first page.

NOTE: You must provide the full data in the header/footer, and not via a network request. Loading files such as external CSS, Js or Fonts won't work in the header or footer. Instead, we recommend you to embed them in Base64.

Here's an example:

# You can get an API key at https://pdfshift.io
$api_key = 'sk_xxxxxxxxxxxx'

$params = array (
    'source' => 'https://en.wikipedia.org/wiki/PDF',
    'header' => array (
        'source' => '<div>Page {{ page }} over a total of {{ total }}. Made on {{ date }}</div>',
        'height' => 150,
        'start_at' => 2
    )
)

$curl = curl_init('https://api.pdfshift.io/v3/convert/pdf');
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, json_encode($params));
curl_setopt($curl, CURLOPT_HTTPHEADER, array(
    'Content-Type: application/json',
    'Authorization: Basic ' . base64_encode('api:' . $api_key)
));

$response = curl_exec($curl);
if ($response === false) {
    $error_message = curl_error($curl);
    curl_close($curl);
    throw new Exception("cURL error: $error_message");
}

// Get the HTTP status code
$http_status = curl_getinfo($curl, CURLINFO_HTTP_CODE);

// Close cURL resource
curl_close($curl);

// Check if the request was successful
if ($http_status !== 200) {
    throw new Exception("Request failed with HTTP status code: $http_status");
}

// Save the file to result.pdf
file_put_contents('result.pdf', $response);

echo 'The PDF document was generated and saved to result.pdf';

The source parameter present in the header/footer accepts a set of variables that will be translated when converting the document.

Here are the properties you can use:

• {{ title }}: The title of the document.
• {{ url }}: The URL of the document.
• {{ page }}: The current page number.
• {{ total }}: The total number of pages in the document.
• {{ date }}: The current date in the format M/D/YY-H:MM am/pm such as "3/16/24, 2:04 PM".

This will allow you to generate a document that looks more like a printable version of a website, with page number and customized header and footer.