Insert Text from a Data Frame by Chunk Name

Looks up a text string from a data frame based on a chunk name and position (before/after). Optionally expands knitr templating syntax ({{...}}) found in the text.

Usage

insert_text(data, chunk, before = TRUE, error_on_empty = NULL, enabled = TRUE)

Arguments

data

A data frame with columns chunk, before, and text.

chunk

Character. The chunk name to look up in data. If the file extension is "rmarkdown", it is stripped automatically.

before

Logical. Whether to retrieve the text marked as "before" (TRUE, default) or "after" (FALSE) the chunk.

error_on_empty

Controls behaviour when no matching text is found:

• TRUE: throws an error via cli::cli_abort().

• FALSE: issues a warning via cli::cli_warn().

• NULL (default): silently returns an empty AsIs object.

enabled

Logical. If FALSE, the function returns I(character(0)) immediately without any lookup. Can be set globally via global_settings_set(new = list(enabled = FALSE), fn_name = "insert_text").

Value

An I()-wrapped character string. If no match is found and error_on_empty is NULL, an empty AsIs character vector.

Details

The function filters data for rows matching the given chunk and before values. If exactly one row matches, its text column is returned. If the text contains knitr templating delimiters ({{), it is expanded with knitr::knit_expand().

Examples

if (FALSE) { # \dontrun{
texts <- data.frame(
  chunk = c("intro", "intro"),
  before = c(TRUE, FALSE),
  text = c("Before the chunk.", "After the chunk.")
)
insert_text(texts, "intro", before = TRUE)
insert_text(texts, "intro", before = FALSE)
} # }