README

A plugin for transforming PDFs using Imager X.
Also, an example of how to make a custom file adapter for Imager X.

Requirements

This plugin requires Imager X 4.1+/5.0+, Craft CMS 4.0+/5.0+, PHP 8.0+ and Imagick with support for opening PDFs.

Support for opening PDFs, what does it mean?

As a start, it means that ghostscript needs to be installed on the server, and available to ImageMagick as a delegate format. It usually is.

Where you're more likely to encounter issues is that in some environments access to open PDFs may be restricted by your ImageMagick policy file. This is an XML file that sets the resource and security policy for ImageMagick, and in turn Imagick. On Ubuntu, it's located in /etc/ImageMagick-6/policy.xml (if you have ImageMagick 6, replace the 6 with 7 if that's what's installed), a google search will probably help you figure out where it is on your distro.

If you get an error (on your log or debug bar) saying something about PDFs and policy, you probably have this in that file:

<policy domain="coder" rights="none" pattern="PDF" />

Changing the rights to read|write:

<policy domain="coder" rights="read|write" pattern="PDF" />

Make sure to restart your webserver/php-fpm after making changes, or the old settings will be cached. If that didn't work there're more tips in this StackOverflow-thread that you can try.

Installation

To install the plugin, follow these instructions:

1. Install with composer via composer require spacecatninja/imager-x-pdf-adapter from your project directory.
2. Install the plugin in the Craft Control Panel under Settings → Plugins, or from the command line via ./craft install/plugin imager-x-pdf-adapter.

Usage

Install and configure the adapter as described below.

You can now transform PDF files simply by adding a PDF file to Imager's transformImage method:

{% set transforms = craft.imagerx.transformImage(myPdfAsset, { width: 200 }) %}

You can pass configuration parameters to the adapter, using the adapterParams transform parameter:

{% set transforms = craft.imagerx.transformImage(myPdfAsset, { width: 200, adapterParams: { density: 72, page: 5 } }) %}

You can also create the adapter as a separate step, with the advantage of being able to better control settings, and inspecting the PDF.

{% set pdf = craft.pdfadapter.load(asset, { density: 300 }) %}

# pages: {{ pdf.getNumPages() }}<br>

{% do pdf.setPage(5) %}
{% set transformPage5 = craft.imagerx.transformImage(pdf, { width: 600 }) %}

{% do pdf.setPage(pdf.getNumPages()) %}
{% set transformLastPage = craft.imagerx.transformImage(pdf, { width: 600 }) %}

Auto generation

The PDF adapter works perfectly with the auto generation functionality in Imager. The only thing you need to do, is add pdf to the list of safe file formats to transform, using the config setting 'safeFileFormats'.

'safeFileFormats' => ['jpg', 'jpeg', 'gif', 'png', 'pdf']

Configuring

You can configure the adapter by creating a file in your config folder called imager-x-pdf-adapter.php, and override settings as needed.

defaultDensity [int]

Default: 144
Sets the default density/dpi to use when converting from pdf to bitmap image.

The higher the number, the larger the resulting file will be, and the better the quality. But it'll also require more resources, and opening PDFs is a resource intensive endeavour, so be careful.

defaultFormat [string]

Default: 'png'
Sets the default format of the temporary bitmap image that the adapter generates. You can of course transform this to whatever format you'd like later, using Imager.

cacheEnabled [bool]

Default: true
Enables/disables caching of generated images. Only disable this if testing, as it will seriously impact performance.

cacheDuration [bool|int]

Default: false
Sets the cacheDuration that's used if cacheEnabled is true. By default, forever. Clearing the Imager runtime cache will also clear this cache.

Price, license and support

The plugin is released under the MIT license. It requires Imager X, which is a commercial plugin available in the Craft plugin store.