WrapRmd

An RStudio Addin to wrap paragraphs of RMarkdown text without inserting line breaks into inline R code.

Installation

Install WrapRmd from GitHub with:

# install.packages("devtools")
devtools::install_github("tjmahr/WrapRmd")

Overview

Here is some nice looking RMarkdown text, but it runs well past the 80 character width we'd like to maintain in our document.

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum a `r max(iris$Sepal.Length)`, viverra nisl at, luctus ante = `r length(letters) * 2 + 100`.

The inline R code r max(iris$Sepal.Length) runs from column 72 to column 96. The most natural place to insert a line break is the space r between max(iris$Sepal.Length). That would unfortunately break the inline R code.

If we highlight the text and call the Wrap Rmd addin, we get the following:

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vestibulum a
`r max(iris$Sepal.Length)`, viverra nisl at, luctus ante =
`r length(letters) * 2 + 100`.

Importantly, there is no line break inserted inside of the inline R code r max(iris$Sepal.Length), meaning that wrapping the text will not break inline R code.

Normalization

This package uses commonmark to wrap and reformat markdown text. This pipeline is advantageous because commonmark handles the difficult work of parsing the markdown text. But because wrapping goes through commonmark, selected text may be normalized or escaped during rewrapping. What the WrapRmd package provides is some additional work to handle inline R Markdown and to undo some of the commonmark normalization that conflicts with RMarkdown features.

In the following animation, we can see three (useful) commonmark normalizations: HTML entities are converted into proper characters, the text in the list is wrapped and cleaned up, and the issue numbers get an escape on the # character.

Other notes

How to run addins. There are two ways to run or view addins.

1. Tools > Addins, to view addins, run them, or set keyboard shortcuts.

2. Tools > Show Command Palette, then start typing the name of the addin to run. As a reminder, the Command Palette's keyboard shortcut is Ctrl+Shift+P or Cmd+Shift+P.

Package options. There are three package options with the following default values. See ?commonmark::markdown_commonmark()

WrapRmd.width = 80         # desired width of output text
WrapRmd.smart = FALSE      # whether to use "smart" punctuation 
WrapRmd.extensions = TRUE  # whether to enable GitHub extensions

Bonus Addins

Flip Backslashes to Forward Slashes: Converts Windows-style backslashes (\) to forward slashes (/) in the current selection.

Knit Selection: Runs the selected text through knitr/commonmark to preview what the rendered markdown/html output will look like.

Assign argument defaults: Evaluates comma-separated x = y expressions in the current selection and assigns each value in the global environment.

Note how the environment pane populates with new variables in this example: