# Document Manipulation

knitr::opts_chunk$set(eval = FALSE) The rstudioapi package provides a small family of functions that can be used to interact with documents open in an RStudio session. For example, the following code could be used to insert a ‘last modified’ comment at the start of a document: # construct the text to be inserted fmt <- "# This document was last modified on %s.\n" text <- sprintf(fmt, Sys.Date()) # specify a range where this text should be inserted; here, # we use the first line; that is, the 'range' between the start # of the first row, and the start of the second row range <- rstudioapi::document_range(c(1, 0), c(2, 0)) rstudioapi::insertText(range, text) By default, these APIs target the editor instance either currently focused by the user, or when no such editor is currently focused, the last focused editor. If you need to target a specific editor instance (for example, you want to write code that inserts text into the console), you can use getConsoleEditorContext() to get the id for the console editor: # get console editor id context <- rstudioapi::getConsoleEditorContext() id <- context$id

# send some R code to the console
rstudioapi::insertText(text = "print(1 + 1)", id = id)

# see also: getActiveEditorContext(), getSourceEditorContext()

You can also modify the cursor position through the use of the setCursorPosition() and setSelectionRanges() APIs.

# put the cursor at the end of the document -- note that here,
# Inf is automatically truncated to the actual length of the
# document
rstudioapi::setCursorPosition(Inf)

# select the first 10 even lines in the document
ranges <- lapply(seq(2, by = 2, length.out = 10), function(start) {
rstudioapi::document_range(
c(start, 0),
c(start, Inf)
)
})
rstudioapi::setSelectionRanges(ranges)

See the ?"rstudio-documents" help page for more details.