Generate an interactive variable codebook

code_book() creates an interactive and exportable codebook summarizing selected variables of a data frame. It builds upon varlist() to provide an overview of variable names, labels, classes, and representative values in a sortable, searchable table.

The output is displayed as an interactive DT::datatable() in the Viewer pane (for example in RStudio or Positron), allowing searching, sorting, and export (copy, print, CSV, Excel, PDF) directly.

Usage

code_book(
  x,
  ...,
  values = FALSE,
  include_na = FALSE,
  title = "Codebook",
  filename = NULL,
  factor_levels = c("all", "observed")
)

Arguments

x: A data frame or tibble.
...: Optional tidyselect-style column selectors (e.g. starts_with("var"), where(is.numeric), etc.). Columns can be selected or reordered, but renaming selections is not supported.
values: Logical. If FALSE (the default), displays a compact summary of the variable's values. For numeric, character, date/time, labelled, and factor variables, all unique non-missing values are shown when there are at most four; otherwise the first three values, an ellipsis (...), and the last value are shown. Values are sorted when appropriate (e.g., numeric, character, date). For factors, factor_levels controls whether observed or all declared levels are shown; level order is preserved. For labelled variables, prefixed labels are displayed via labelled::to_factor(levels = "prefixed"). If TRUE, all unique non-missing values are displayed.
include_na: Logical. If TRUE, unique missing value markers (<NA>, <NaN>) are appended at the end of the Values summary when present in the variable. This applies to all variable types. Literal strings "NA", "NaN", and "" are quoted to distinguish them from missing markers. If FALSE (the default), missing values are omitted from Values but still counted in the NAs column.
title: Optional character string displayed as the table caption. Defaults to "Codebook". Set to NULL to remove the title completely. When filename = NULL, the title is also used as the base for export filenames after conversion to a portable ASCII name.
filename: Optional character string used as the base for exported CSV, Excel, and PDF filenames. If NULL (the default), a portable filename is derived from title, falling back to "Codebook" when needed. File extensions are added by the browser/export engine.
factor_levels: Character. Controls how factor values are displayed in Values. "all" (the default; varlist() uses "observed") shows all declared levels, including unused levels. "observed" shows only levels present in the data, preserving factor level order.

Value

A DT::datatable object.

Details

The interactive datatable supports column sorting, global searching, and client-side export to various formats.
Variable selection uses the same tidyselect interface as varlist().
By default, factor variables document all declared levels, including unused levels — appropriate for a schema-oriented codebook. This differs from varlist(), which defaults to "observed" to summarize observed data only. Pass factor_levels = "observed" to mirror varlist()'s default.
All exports occur client-side through the Viewer or Tab.

Dependencies

Requires the following package:

Examples

if (FALSE) { # \dontrun{
if (requireNamespace("DT", quietly = TRUE)) {
  code_book(sochealth)
  code_book(sochealth, starts_with("bmi"))
  code_book(sochealth, starts_with("bmi"), values = TRUE, include_na = TRUE)

  factors <- data.frame(
    group = factor(c("A", "B", NA), levels = c("A", "B", "C"))
  )
  code_book(
    factors,
    values = TRUE,
    include_na = TRUE,
    factor_levels = "observed"
  )

  code_book(
    sochealth,
    starts_with("bmi"),
    title = "BMI codebook",
    filename = "bmi_codebook"
  )
}
} # }