Start Customising Gravity PDF – Developer Documentation
Before You Begin
This section of the documentation is primarily written for developers. Assumed knowledge of WordPress basics, like action and filter hooks, with a solid PHP foundation and HTML / CSS is expected. If that last sentence just went over your head get in touch with our friendly team and we can discuss a solution tailored for you.
We've attempted to make Gravity PDF as developer-friendly as possible. That means there are actions and filters placed all through the software so you can tweak the functionality as you see fit. You can also control the exact look and feel of the generated PDFs using custom PDF templates, which are created using HTML/CSS and a bit of PHP knowledge.
The majority of our developer documentation will be targeted at creating custom PDF templates. You'll learn how to:
- Setup Gravity PDF so it utilises custom templates.
- The different techniques for displaying Gravity Form data in the PDFs – using merge tags or a PHP array.
- How to utilise a PDF configuration file to create template-specific settings.
- Adding a PDF template image so users can see what the custom template looks like.
- How the PDF hierarchy works so you can override core templates.
Tell me more about setting up custom PDF templates.
Supported PDF Features
Along with learning the ins and outs to create a template and configuration file, we'll go into detail about the common features you can use when laying out your PDF using HTML/CSS.
- Supported HTML / CSS: it's not like your web browser.
- Headers and Footers
- Background Images
- Rounded Corners
- Page Breaks
For those developers looking for in-depth knowledge about the PDF engine, mPDF, which Gravity PDF uses we recommend you review the mPDF user and reference guide.
Actions / Filters
We've worked hard to document as many of the filters and actions available in Gravity PDF. This includes changing the output of particular Gravity Form fields to controlling the PDF security (we call it middleware). All filters documentation is located under the Filter Hooks category in the sidebar, while actions are found under Action Hooks.
If you want to request a new filter or action be added please open a new ticket on GitHub.