Entity Print Module: Create PDF from HTML

Question

I´m trying to use the entity_print module for generating a PDF in Drupal 8. I want to print out HTML. My module has no entities it gets data from a solr server and generates HTML output.

My first thing is to make a route and a sort of flag to fire the pdf generation:

mymodule.page_detail:
path: '/detail/{Title}/{ObjIdentifier}'
defaults:
_controller: '\Drupal\mymodule\Controller\myController::detailpage'
Title: ''
ObjIdentifier: ''
ViewPdf: '0'
...

mymodule.page_detail_pdf:
path: '/detail/pdf/{Title}/{ObjIdentifier}'
defaults:
_controller: '\Drupal\mymodule\Controller\myController::detailpage'
Title: ''
ObjIdentifier: ''
ViewPdf: '1'

...

Then in my Controller I check for

if (isset($myModuleViewPdf) && $myModuleViewPdf == "1") {
  ...

Now the entity Print magic should come into play. I use the services and make a print engine and a print builder:

$print_engine = \Drupal::service('plugin.manager.entity_print.print_engine')->createSelectedInstance('pdf');
$print_builder = \Drupal::service('entity_print.print_builder');

Now I´m struggeling somehow. When I look over the functions docroot/modules/entity_print/src/PrintBuilder.php

I see that they are using entities for the output but I want to use HTML. How can I do this?

Greetings Lars

Answer 1

If you want to send the PDF directly to the user then you can do something like this:

// Get your HTML from Solr.
$html = $this->getHtmlFromSolr();

$print_engine = \Drupal::service('plugin.manager.entity_print.print_engine')->createSelectedInstance('pdf');

$print_engine->addPage($html);
$print_engine->send('mydocument.pdf');

Answer 2

The previos code works the first time you load the page but will throw errors in your watchdog, and you will give a WSOD when you reload the page.

You need a new Strem Response for the PDF, you cannot reuse the controller stream.

$html = $this->getHtmlFromSolr();

$print_engine = \Drupal::service('plugin.manager.entity_print.print_engine')->createSelectedInstance('pdf');
$print_engine->addPage($html);

return (new StreamedResponse(function () use ($print_engine) {
  $print_engine->send('youdocument.pdf');
}))->send();