Merge pull request #37 from AdamSpannbauer/issue#35

rework highlighting #35

DESCRIPTION

@@ -23,7 +23,7 @@ Imports:
     purrr
 Encoding: UTF-8
 LazyData: true
-RoxygenNote: 7.1.0
+RoxygenNote: 7.1.2
 URL: https://github.com/AdamSpannbauer/r_regex_tester_app
 BugReports: https://github.com/AdamSpannbauer/r_regex_tester_app/issues
 Suggests: 

NAMESPACE

@@ -13,3 +13,5 @@ importFrom(golem,with_golem_options)
 importFrom(htmltools,HTML)
 importFrom(shiny,column)
 importFrom(shiny,shinyApp)
+importFrom(utils,URLdecode)
+importFrom(utils,URLencode)

R/app_server.R

@@ -3,6 +3,8 @@
 #' @param input,output,session Internal parameters for {shiny}.
 #'     DO NOT REMOVE.
 #' @import shiny
+#' @importFrom utils URLdecode
+#' @importFrom utils URLencode
 #' @noRd
 app_server = function(input, output, session) {
   shiny::observe({

R/highlight_test_str.R

@@ -120,6 +120,11 @@ highlight_test_str = function(str, pattern, ignore_case = TRUE,
                                              match_start, match_end)],
                              cols = c(match_ind, match_start, match_end))
     match_df = unique(match_df)
+
+    # modifying string in place using indices
+    # work back to front to avoid disrupting indices
+    match_df = data.table::data.table(match_df)
+    match_df = match_df[order(match_ind, capture_start, decreasing = TRUE), ]
   } else {
     match_end = matches_raw + attr(matches_raw, "match.length") - 1
 
@@ -134,16 +139,18 @@ highlight_test_str = function(str, pattern, ignore_case = TRUE,
       match,
       "</span>"
     )]
+
+    # modifying string in place using indices
+    # work back to front to avoid disrupting indices
+    match_df = match_df[order(match_ind, decreasing = TRUE), ]
   }
 
   txt = str
-  buffer = 0
   for (i in seq_len(nrow(match_df))) {
     stringr::str_sub(txt,
-                     match_df$match_start[i] + buffer,
-                     match_df$match_end[i] + buffer) = "%s"
+                     match_df$match_start[i],
+                     match_df$match_end[i]) = "%s"
     txt = sprintf(txt, match_df$replacements[i])
-    buffer = buffer + nchar(match_df$replacements[i]) - nchar(match_df$match[i])
   }
 
   txt