Auto-detect html in str_view()

Author: hadley

R/view.R

@@ -9,7 +9,9 @@
 #'   If `FALSE`, shows only the strings that don't match the pattern.
 #'   Otherwise (the default, `NA`) displays both matches and non-matches.
 #' @param html Use HTML output? If `TRUE` will create an HTML widget;
-#'   if `FALSE` will style using ANSI escapes.
+#'   if `FALSE` will style using ANSI escapes. The default will prefers
+#'   ANSI escapes if available in the current terminal; you can override by
+#'   setting `option(stringr.html = TRUE)`.
 #' @export
 #' @examples
 #' # Show special characters
@@ -22,7 +24,8 @@
 #'
 #' # Show all matches
 #' str_view_all(c("abc", "def", "fgh"), "d|e")
-str_view <- function(string, pattern = NULL, match = NA, html = getOption("stringr.html", TRUE)) {
+str_view <- function(string, pattern = NULL, match = NA, html = NULL) {
+  html <- str_view_use_html(html)
   out <- str_view_filter(string, pattern, match)
   if (!is.null(pattern)) {
     out <- str_replace(out, pattern, str_view_highlighter(html))
@@ -32,7 +35,8 @@ str_view <- function(string, pattern = NULL, match = NA, html = getOption("strin
 
 #' @rdname str_view
 #' @export
-str_view_all <- function(string, pattern = NULL, match = NA, html = getOption("stringr.html", TRUE)) {
+str_view_all <- function(string, pattern = NULL, match = NA, html = NULL) {
+  html <- str_view_use_html(html)
   out <- str_view_filter(string, pattern, match)
   if (!is.null(pattern)) {
     out <- str_replace_all(out, pattern, str_view_highlighter(html))
@@ -56,6 +60,10 @@ str_view_filter <- function(x, pattern, match) {
 
 # Helpers -----------------------------------------------------------------
 
+str_view_use_html <- function(html) {
+  html %||% getOption("stringr.html") %||% (cli::num_ansi_colors() < 8L)
+}
+
 str_view_highlighter <- function(html = TRUE) {
   if (html) {
     function(x) paste0("<span class='match'>", x, "</span>")

man/str_view.Rd

@@ -1,19 +1,34 @@
 # view works
 
     Code
-      str_view(x, "[aeiou]")$x$html
+      str_view(x, "[aeiou]", html = TRUE)$x$html
     Output
       <ul>
         <li><span class='match'>a</span>bc</li>
         <li>d<span class='match'>e</span>f</li>
         <li>fgh</li>
       </ul>
     Code
-      str_view_all(x, "d|e")$x$html
+      str_view_all(x, "d|e", html = TRUE)$x$html
     Output
       <ul>
         <li>abc</li>
         <li><span class='match'>d</span><span class='match'>e</span>f</li>
         <li>fgh</li>
       </ul>
 
+---
+
+    Code
+      str_view(x, "[aeiou]", html = FALSE)
+    Output
+      [a]bc
+      d[e]f
+      fgh
+    Code
+      str_view_all(x, "d|e", html = FALSE)
+    Output
+      abc
+      [d][e]f
+      fgh
+

tests/testthat/_snaps/view.md

@@ -2,9 +2,15 @@
 test_that("view works", {
   x <- c("abc", "def", "fgh")
   expect_snapshot({
-    str_view(x, "[aeiou]")$x$html
-    str_view_all(x, "d|e")$x$html
+    str_view(x, "[aeiou]", html = TRUE)$x$html
+    str_view_all(x, "d|e", html = TRUE)$x$html
   })
+
+  expect_snapshot({
+    str_view(x, "[aeiou]", html = FALSE)
+    str_view_all(x, "d|e", html = FALSE)
+  })
+
 })
 
 test_that("match argument controls what is shown", {