Pipe operator

Description

See magrittr::%>% for details.

Usage

lhs %>% rhs

Arguments

Value

The result of calling rhs(lhs).

RStudio / Positron Addin: Crawl R Chunks from a URL

Description

When invoked from the Addins menu or a keyboard shortcut, this function:

Usage

addin_crawl_chunks()

Details

1. Opens a dialog asking the user for a web URL.

2. Auto-detects the best extraction strategy.

3. Fetches the page and extracts R code chunks.

4. Inserts the extracted code into the active source editor at the current cursor position.

Value

Called for side effects (i.e., inserting text); returns NULL invisibly.

Keyboard shortcut

After installing the package, open Tools > Modify Keyboard Shortcuts… (RStudio) or the Command Palette in Positron, search for "Extract External R Code and Insert Inline", and assign your preferred shortcut (e.g. Ctrl+Shift+U / Cmd+Shift+U).

Examples

if (interactive() && rstudioapi::isAvailable()) {
  addin_crawl_chunks()
}

Collapse a character vector of code chunks into a single insertable string

Description

Each chunk is separated by a comment banner so the user can visually distinguish chunk boundaries once inserted into the editor.

Usage

collapse_chunks(chunks)

Arguments

Value

A single character string ready for insertion with annotations for chunk boundaries.

Fetch R code chunks from any URL

Description

The primary engine of the ctrlvee package. Give it a URL to a raw source file, a GitHub Gist, or a rendered HTML page and it returns the R code chunks found there.

Usage

crawl_chunks(url, strategy = c("auto", "raw", "html"), verbose = TRUE)

Arguments

Value

A character vector of R code chunk bodies. Returns character(0) if no R chunks are found.

Examples

## rendered Quarto book chapter (HTML strategy detected)
chunks <- crawl_chunks("https://r4ds.hadley.nz/data-visualize.html")


## GitHub Gist ... plain .R file (raw strategy detected)
chunks <- crawl_chunks(
  "https://gist.github.com/vpnagraj/59fa609c5adf47c8c7a5b156eb261be7"
)

## you can also dictate a specific strategy
chunks <- crawl_chunks("https://r4ds.hadley.nz/data-visualize.html", strategy = "html")

Fetch and extract R code blocks from a rendered HTML page

Description

Downloads an HTML page (e.g., a rendered Quarto book chapter) and extracts code blocks that are tagged as R.

Usage

crawl_chunks_html(url, verbose = interactive())

Arguments

Details

The function looks for ⁠<code>⁠ elements whose class attribute matches known patterns for R source code (e.g., ⁠sourceCode r⁠, language-r). It then grabs the inner text, stripping any syntax highlighting ⁠<span>⁠ elements.

It is important to note that:

• Chunk options (labels, echo, eval, etc.) are lost in rendered HTML because the renderer strips them.

• Output blocks that the renderer styled identically to source blocks may occasionally be captured. A heuristic filters out blocks where the majority (>50%) of lines look like R console output (e.g., ⁠[1]⁠, ⁠##⁠).

Value

A character vector where each element is the text content of one R code block, in document order. Returns character(0) if none are found.

Examples

## extract R code from a rendered Quarto book chapter
chunks <- crawl_chunks_html("https://r4ds.hadley.nz/data-visualize.html")
length(chunks)
cat(chunks[[1]])

Fetch and extract R code from a raw source URL

Description

Downloads the raw text content of a URL (typically a .qmd, .Rmd, .md, or .R file served as plain text) and extracts R code.

Usage

crawl_chunks_raw(url, verbose = TRUE)

Arguments

Details

For Markdown-family files, fenced R code blocks are extracted individually. For plain .R files (or any file where no fenced chunks are found), the entire file content is returned as a single chunk.

Value

A character vector where each element is the body of one R chunk. For plain .R files, a vector of length 1 containing the full file. Returns character(0) if the file is empty.

Examples

## fenced chunks from a Quarto source file
chunks <- crawl_chunks_raw(
  "https://raw.githubusercontent.com/hadley/r4ds/main/data-visualize.qmd"
)

## plain .R file from a GitHub Gist
chunks <- crawl_chunks_raw(
  "https://gist.githubusercontent.com/vpnagraj/59fa609c5adf47c8c7a5b156eb261be7/raw"
)

Detect the best extraction strategy for a URL

Description

Examines the URL pattern and returns a strategy string that tells the caller which extraction function to use. This will be one of either: "raw" (URL points directly to a raw source file or a GitHub Gist) or "html" (URL is a rendered web page like a Quarto book chapter or pkgdown site).

Usage

detect_strategy(url)

Arguments

Details

Detection is entirely URL-based (no network requests) and intentionally conservative; when in doubt it falls back to "html".

Rules (evaluated in order):

1. Contains gist.githubusercontent.com or matches ⁠gist.github.com/<user>/<hash>⁠: "raw"

2. Contains raw.githubusercontent.com or ends in .Rmd, .qmd, .md, .R, or .Rmarkdown: "raw"

3. Everything else: "html"

Value

One of "raw", "github", or "html".

Examples

detect_strategy("https://gist.github.com/vpnagraj/59fa609c5adf47c8c7a5b156eb261be7")

detect_strategy("https://raw.githubusercontent.com/hadley/r4ds/main/data-visualize.qmd")

detect_strategy("https://r4ds.hadley.nz/data-visualize.html")

Extract R code blocks from an HTML string

Description

Helper function to do HTML-parsing in crawl_chunks_html(). Also exported so users can call it on local HTML strings if needed.

Usage

extract_r_chunks_from_html(html)

Arguments

Value

Character vector of extracted R code bodies.

Extract fenced R code chunks from a Markdown text string

Description

A helper to go line-by-line through a Markdown file to find the common R code fence styles used in R Markdown, Quarto, and GitHub Markdown. Note that non-R fenced blocks (e.g., python, sql, etc.) are skipped.

Usage

extract_r_chunks_from_markdown(text)

Arguments

Value

Character vector of extracted code bodies.

Minimal HTML escaping for IDE dialog messages

Description

Helper function to escape HTML in RStudio rstudioapi::showDialog() dialog rendering.

Usage

html_escape(x)

Arguments

Value

The same vector but with &, <, and > escaped.

Make an HTTP GET request with standard headers and timeout

Description

Helper wrapper for httr2 boilerplate so each strategy doesn't have to repeat it. Returns the response object or stops with a descriptive error message.

Usage

http_get(url, accept = NULL, token = NULL)

Arguments

Value

An httr2 response object.

Validate that a string looks like a URL

Description

Cursory check that the input starts with ⁠http://⁠ or ⁠https://⁠ and contains at least one dot in the domain portion.

Usage

is_valid_url(url)

Arguments

Value

Logical TRUE or FALSE as to whether the string passes the basic pattern

Normalize a URL before strategy dispatch

Description

Converts known URL patterns to their most fetchable form. Currently handles GitHub Gist URLs, converting the HTML view to the raw content endpoint. Non-gist URLs pass through unchanged.

Usage

normalize_url(url)

Arguments

Value

URL either as-is or normalized per the logic.