View: View a data object inline when not in an interactive R session

Description

A drop-in replacement for utils::View(). In an interactive R session it behaves identically to utils::View(), opening the RStudio / R Console data viewer. In a non-interactive context such as an R Markdown or Quarto document, where utils::View() typically errors, it instead renders an interactive DT::datatable() inline so users can still inspect the data without their document failing to render.

Usage

View(x, title = NULL, n = 1000L, full = FALSE, seed = NULL, quiet = FALSE)

Value

In an interactive session, invisibly returns NULL (called for the side effect of displaying x in a viewer). In a non-interactive session, returns a DT::datatable() htmlwidget -- except inside webR (where pandoc is unavailable), where it renders a self-contained static HTML table through the browser viewer and invisibly returns NULL.

Arguments

x: an R object which can be coerced to a data frame.
title: title for the viewer window. Defaults to the name of x prefixed by Data: , matching the convention used by utils::View().
n: maximum number of rows to show in the inline DT::datatable(). When x has more than n rows and full = FALSE, a random sample of n rows is shown instead of the whole data frame. Default 1000.
full: if TRUE, show every row of x in the inline table instead of sampling (may be slow, and DT may warn, for very large data). Default FALSE.
seed: optional integer seed making the random sample reproducible. The global random-number stream is left unchanged regardless of whether seed is supplied. Default NULL (a fresh sample each call).
quiet: if TRUE, suppress the message announcing that a random sample is being shown. Default FALSE.

Details

For large data frames a client-side DT::datatable() is slow and warns that the data is too big. So in non-interactive contexts, when x has more than n rows and full = FALSE, View() shows a random sample of n rows and emits a message saying so. This keeps "just look at the data" fast for beginners while making the size limitation explicit. The interactive utils::View() path is unaffected (RStudio's viewer handles large data natively), so n / full / seed / quiet apply only to the inline DT rendering.

Examples

Run this code

if (FALSE) {
  # In an interactive R session, behaves like utils::View():
  View(un_member_states_2024)

  # In an R Markdown or Quarto document, renders an interactive
  # DT::datatable() inline instead of erroring:
  View(un_member_states_2024)

  # For large data a random sample is shown by default; override with:
  View(some_big_data, full = TRUE)   # all rows (may be slow)
  View(some_big_data, n = 500)       # sample 500 rows instead of 1000
  View(some_big_data, seed = 42)     # reproducible random sample
  View(some_big_data, quiet = TRUE)  # no "random sample" message
}