Solved the LaTeX2exp error. Closes plotly#2027

Author: moutikabdessabour

R/ggplotly.R

@@ -1300,14 +1300,24 @@ faced <- function(txt, face = "plain") {
 bold <- function(x) paste("<b>", x, "</b>")
 italic <- function(x) paste("<i>", x, "</i>")
 
+# generic S3 method to allow for class specific implementations
+uniq <- function(x){
+  UseMethod("uniq", x)
+}
+
 # if a vector that has one unique value (ignoring missings), return that value
-uniq <- function(x) {
+uniq.default <- function(x) {
   u <- unique(x)
   if (identical(u, NA) || length(u) == 0) return(u)
   u <- u[!is.na(u)]
   if (length(u) == 1) u else x
 }
 
+# if TeX object convert to character first
+uniq.TeX <- function(x){
+  print(uniq.default(as.character(x)))
+}
+
 # theme(strip.background) -> plotly.js rect shape
 make_strip_rect <- function(xdom, ydom, theme, side = "top") {
   rekt <- rect2shape(theme[["strip.background"]])