How to render a "github_document" Rmd without generating the HTML preview?

2 min read 05-10-2024

How to render a "github_document" Rmd without generating the HTML preview?

RMarkdown Magic: Rendering Without the Preview

Have you ever found yourself working on an R Markdown document (.Rmd) in RStudio and wished you could just knit it to your desired output format without having to deal with the automatic HTML preview? It's a common desire, especially when you're focused on specific output like PDF or Word documents. Let's explore how to achieve this without the preview popping up.

The Problem: Unwanted HTML Preview

RStudio's default behavior is to automatically generate an HTML preview of your .Rmd file whenever you knit it. This is helpful for quick checks, but it can be frustrating if you're only interested in generating a specific output format, like a PDF for a report or a Word document for a manuscript.

The Solution: Taming the Preview with Knit Options

The key to controlling this behavior lies within the knit options. Here's how you can render your .Rmd without the preview:

Add 'preview = FALSE' to your YAML Header:
```
---
title: "My Awesome Report"
author: "Your Name"
output: 
  pdf_document:
    preview: FALSE  
---
```
By adding preview: FALSE within the output section of your YAML header, you're instructing RStudio to skip the HTML preview generation.
Knitting with knitr:

Alternatively, you can use the knitr package directly to control the output without the preview:
```
library(knitr)
knit('my_report.Rmd', output = 'my_report.pdf', preview = FALSE)
```
This code snippet allows you to specify the output format ('pdf' in this case) and explicitly disable the preview.

The "Why" and "When" of Preview Control

While the preview is helpful for visual verification, there are scenarios where it can be a hindrance:

Large Documents: If your .Rmd document contains extensive content, the preview generation can become time-consuming, slowing down your workflow.
Specific Output: When your goal is a particular output format, the preview might not accurately represent the final version.
Automation: For automated workflows where you only need a specific output, generating an unnecessary preview adds an extra step.

Beyond the Basics: Advanced Options

The preview option is just the tip of the iceberg. The knitr package provides a wealth of control over your .Rmd rendering, including:

Output Format Customization: You can refine PDF, Word, and HTML output with specific settings.
Code Chunk Options: You can customize how code chunks are displayed, run, and output.
Advanced Styling: The knitr package offers a wide range of options for styling your output documents.

Resources for Deeper Exploration

R Markdown Cookbook: https://bookdown.org/yihui/rmarkdown-cookbook/
knitr Package Documentation: https://cran.r-project.org/web/packages/knitr/knitr.pdf
R Markdown Tutorial: https://rmarkdown.rstudio.com/

By mastering the art of preview control, you'll streamline your R Markdown workflows and create more efficient and focused document production processes.