README

A Silverstripe module for printing a given html-template into a pdf file using headless chromium in php. This module enables the creation of zugferd compatible e-invoices. For this the additional module horstoeko/zugferd is required.

Installation

This module can be installed via Composer with

composer require atwx/silverstripe-headless-pdf

Requirements

This module requires the following modules

php: "^8.3",
silverstripe/framework: "^6.0",
chrome-php/chrome: "^1.15"

Configuration

The browser-factory will search for the environment variable CHROME_PATH when starting. To prevent it from guessing, this variable should be set in your .env (configuration instruction from chrome-php/chrome).

If the browser has trouble rendering the PDF (mostly timeouts), you can try different navigation wait events. This can be set in the WAITING_MODE variable in the .env. All available events can be found here. For each constant the string version has to be used. In this module the default value is 'networkIdle'.

This pdf module uses hashes created with the sha256 algorithm for protecting the html. Therefore you need to set the HEADLESS_PDF_HASH_KEY variable in your .env otherwise the pdf creation return an 403 http error. Any other authentication method has to be disabled for the HeadlessPDFController->renderPdfTemplate function.

Additionally if you are using ddev you can set the IS_DDEV variable in your .env to "true". By doing this sandboxing is disabled and certificate errors are ignored allowing printing PDFs locally. To use headless chrome in ddev you need the headless chrome add-on by gebruederheitz.

Usage

To print a pdf you need to create a new instance of HeadlessPDFService and call its generatePdf function. This function takes up to 5 arguments:

• a link for rendering the html-template which will then be printed as a pdf,
• a string containing the filename,
• a bool getPath for getting the pdf as a string (default) or as a path to a temporary file,
• optional xml-data for creating zugferd compatible e-invoices (this requires additionally the horstoeko/zugferd module),
• and an optional array for php-chrome options changing the default pdf-options defined in the HeadlessPDFService.

The link given as first argument needs to point to

/pdf/renderPdfTemplate/<optional ID>

calling the HeadlessPDFController with the following get-parameters:

• template containing the full template name/path (called with renderWith($template)),
• hash generated with HeadlessPDFController::generateHash,
• optional className to use an object in the template corresponding to $ID in the link. This object is callable as $TemplateObject in the template,
• optional controller to use an iterable list of dataobjects in the template callable as $TemplateDatalist. This list can be defined in a getPdfDatalist function in the given controller,
• optional variation containing a string callable as Variation in the template to enable similar pdf versions without the need to create a new template.

For the correct rendering of the pdf received as a string you need to set the two HTTP-headers

$this->getResponse()->addHeader('Content-Type', 'application/pdf')
$this->getResponse()->addHeader('Content-Disposition', 'inline; filename="' . <filename> . '.pdf"')