Generating PDF Cut Sheets with R Markdown, Pagedown, and HTML/CSS

An example (for SEPTA’s Bus Network Redesign) of how to generate PDF cut sheets using R Markdown, Pagedown, and HTML/CSS.

This content was presented to Nelson\Nygaard Staff at a Lunch and Learn webinar on Thursday, September 22nd, 2022, and is available as a recording here and embedded below.

Today’s Agenda

• R Markdown refresher (15 min)
• Preparing data for cut sheets (20 min)
• Styling our cut sheets using CSS classes (25 min)

R Markdown Refresher

I am going to refresh our memories on what R Markdown is by referring to a previous webinar

Then we are going to talk about Pagedown, which will create paged HTML outputs for us, that will enable us to utilize the power of CSS styling to format a printable PDF document.

Data Preparation

We will be going through the ETL (Extract, Transform, Load) script I developed to ingest several sources of information and produce the processed data utilized in generating cut sheets.

This data processing includes several key points:

• Ingesting external change sheet metadata (e.g., Excel sheets)
• Extracting span and frequency data from existing and proposed GTFS feeds
• Constructing the base of the span & frequency table to be styled further in CSS using kable
• Identification of connecting frequent routes

Styling

CSS – Cascading Style Sheets is a powerful tool that is used to style web pages. We will be taking advantage of CSS to style our cut sheets in a programmatic way.

Key points to note about using CSS to style in R Markdown & Pagedown:

• Using CSS classes is what will drive most of our style settings.
• Using the inspect elements feature in Google Chrome in the HTML version of our cut sheets will help us test & troubleshoot styling.
• Using parent-child relationships in HTML tags to inhereit style attributes from parent elements.