epub generation fails with the sample project

[johnblommers]

Following along with the installation instructions we find we can easily generate a PDF file but epub generation errors out:

./vendor/bin/ibis-next epub
PHP Warning:  Module "curl" is already loaded in Unknown on line 0
PHP Warning:  Module "gd" is already loaded in Unknown on line 0
✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨
✨ EPUB generation is a Working in Progress!! ✨
✨                Stay tuned!!                ✨
✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨✨
Loading config/assets from: ./
Loading config file from: .//ibis.php
Loading content from: .//content
==> Preparing Export Directory ...
==> Parsing Markdown ...
==> Adding Book Cover .//assets/cover-ibis.webp ...
PHP Fatal error:  Uncaught Error: Class "DOMDocument" not found in /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/phpepub/src/PHPePub/Core/EPub.php:397
Stack trace:
#0 /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/phpepub/src/PHPePub/Core/EPub.php(420): PHPePub\Core\EPub->findIdAttributes()
#1 /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/phpepub/src/PHPePub/Core/EPub.php(1424): PHPePub\Core\EPub->extractIdAttributes()
#2 /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/phpepub/src/PHPePub/Core/EPub.php(1380): PHPePub\Core\EPub->addReferencePage()
#3 /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/ibis-next/src/Commands/BuildEpubCommand.php(140): PHPePub\Core\EPub->setCoverImage()
#4 /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/ibis-next/src/Commands/BuildEpubCommand.php(70): Ibis\Commands\BuildEpubCommand->buildEpub()
#5 /home/johnb/Desktop/my-first-ebook/vendor/symfony/console/Command/Command.php(326): Ibis\Commands\BuildEpubCommand->execute()
#6 /home/johnb/Desktop/my-first-ebook/vendor/symfony/console/Application.php(1078): Symfony\Component\Console\Command\Command->run()
#7 /home/johnb/Desktop/my-first-ebook/vendor/symfony/console/Application.php(324): Symfony\Component\Console\Application->doRunCommand()
#8 /home/johnb/Desktop/my-first-ebook/vendor/symfony/console/Application.php(175): Symfony\Component\Console\Application->doRun()
#9 /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/ibis-next/ibis-next(31): Symfony\Component\Console\Application->run()
#10 /home/johnb/Desktop/my-first-ebook/vendor/bin/ibis-next(117): include('...')
#11 {main}
  thrown in /home/johnb/Desktop/my-first-ebook/vendor/hi-folks/phpepub/src/PHPePub/Core/EPub.php on line 397

The message does say that epub generation is a work in progress so perhaps I'm being impatient ??

[roberto-butti]

Hi @johnblommers thank you for the feedback. Really appreciated.
This tool uses DOMDocument in the process for converting markdown.
So DOMDocument is a dependency, and DOMDocument is shipped with a specific PHP Extension:
https://www.php.net/manual/en/dom.requirements.php

You need to install php-xml extension (or php-dom , in some operating system you have php-dom).

I will open a PR to set all the extension needed in the composer.json in order to provide a better message in the case the extension is missed.

You can run

composer check-platform-reqs

to see if something is missing.

If everything is fine you should see something like this:

ext-ctype    *          success provided by symfony/polyfill-ctype
ext-dom      20031129   success
ext-filter   8.3.2      success
ext-gd       8.3.2      success
ext-json     8.3.2      success
ext-mbstring *          success provided by symfony/polyfill-mbstring
ext-zlib     8.3.2      success
php          8.3.2      success

[johnblommers]

Aha, excellent! All I had to do was type:

sudo apt install php-xml

and ePub generation completed with success.

[roberto-butti]

Great, I am happy to know that you updated your environment. I just merged a PR to set all the ext-* dependencies in the composer.json file #20