Drupal 10 /11 compatibility fixes

Applied and tested patch #2 in Drupal 9.5.7 and 10.0.8. Patch applied cleanly and makes this module D10 compatible. Functionality is working fine.

Moving this to RTBC.

In order this patch works we have to update the mpdf/mpdf library to ^8.0.0 to work with php ^8.0.
When we try to run composer require it breaks because the library is set to ^7.0.0 that requires php ^7.0.0.

Patch for 2.x-dev which allows ^8.0.4

See note in #3331918: PDF using mPDF D10 compatibility? about how to make D10 compatible along with mpdf dependency

I encountered issues with Drupal Version 9.5.11. The module version that I was able to patch is as follows:

name: PDF using mPDF
type: module
description: 'HTML to PDF conversion using mPDF Library'
core: 8.x 
core_version_requirement: ^8 || ^9
package: 'PDF Conversion'
configure: pdf_using_mpdf.admin_form

Details on the errors I had to address, please refer to this screenshot: Link to Screenshot

I successfully resolved the issues with the following patch: Patch Link.

The patch https://www.drupal.org/files/issues/2023-10-17/pdf_using_mpdf_d10_compac... works perfectly. Thank you.

Call to deprecated function render(): in drupal:9.3.0 and is removed from drupal:10.0.0. Use \Drupal\Core\Render\RendererInterface::render() instead.

/src/Controller/GeneratePdf.php

- $renderedNode = render($view)->__toString();
+ $renderedNode = \Drupal::service('renderer')->render($view)->__toString();

I just opened a branch from 3.x and a MR and used the patch from this issue. There are some more problems to solve, so I change the state to work and assign to me.

I will add compatibility to 11.x also.

For existing system the patch is fine, but we will release to 3.x fpr D10/D11.

The MR passed the pipeline.

The MR delivers compatibility with D10 and D11.

I rewrote the part of delivering the PDF and am using Drupal's Response objects now. How about the caching?

Please have a quick review of eveything fits for your needs.

In the next step we will release a RC so that testing becomes easier and more people can participate.

Added title for D11

looks good!

installed 3.x-D10 and it worked without problems. was able to generate pdf of the node as admin.

Thank you all for reporting, contributing and testing!

I merged this code and the code from #3475769 and #3520301 in this merge.

Please use the new alpha version of 3.x branch and give feedback.