Easy Read PDF utility

April 2019 • Node.js, Gatsby

Summary:

Web app to automate repetitive tasks when making a PDF accessible.
When we create an Easy Read PDF at the Information Access Group, we must do a few manual tweaks to the PDF in Acrobat, including manipulating the order of tags.
I worked out how to automate some of these tasks using the pdfassembler NPM library.

Background context

At the Information Access Group, when we are creating an Easy Read document in Microsoft Word, we use a table structure to lay out images and text side by side. This isn’t ideal because when you export a PDF, the content is in a table tag, even though it is not an accessible data table. An accessible data table requires a meaningful header cell that describes the content that comes below.
In my early days at the Information Access Group, one of my main tasks was creating accessible PDFs when we finalised an Easy Read document for a client. This meant I needed to do a lot of manual accessibility work in Acrobat. This included manually ‘stripping the table structure’ - taking the content that was inside the table structure, dragging it out of the table tag, and deleting the table tag.
While this was tedious, it gave me time to think about how we could make this process more efficient.

I found an NPM library called pdfassembler that would allow you to manipulate the structure of a PDF file using JavaScript. This allowed me to work out how to process a PDF and automate repetitive tasks.
To do this in a reliable way, I needed to learn quite a bit about how PDFs work internally. I read through a lot of the PDF Reference, learning how content and tags interact. This involved a lot of trial and error.
This gave me a solid understanding of how PDFs work and how they can be manipulated using JavaScript. This technique came in handy in many projects, especially when we needed to make minor content tweaks across every page in larg e documents (for example, incrementing the page number in the corner of a page after inserting an extra page in the middle of a document).
This tool is now used whenever we create our finished art files for any Easy Read document.