fix #130: check the lenght of the provided caption

R/helpers.R

@@ -335,3 +335,17 @@ splitLine <- function(x, max.width = panderOptions('table.split.cells'), use.hyp
         koRpus::hyphen(s, hyph.pattern = 'en.us', quiet = TRUE)@hyphen[1, 2]
     .Call('pander_splitLine_cpp', PACKAGE = 'pander', x, max.width, use.hyphening, hyphen_f)
 }
+
+
+#' Check if caption is valid
+#' @param caption R object to check
+#' @return boolean
+#' @keywords internal
+check_caption <- function(caption) {
+
+    if (length(caption) > 1)
+        stop('The caption should be exactly one string.')
+
+    if (is.character(caption) | is.null(caption))
+        stop('The caption should be string (character class) or NULL.')
+}

R/pandoc.R

@@ -211,6 +211,8 @@ pandoc.link <- function(...)
 #' @references John MacFarlane (2012): _Pandoc User's Guide_. \url{http://johnmacfarlane.net/pandoc/README.html}
 pandoc.image.return <- function(img, caption = storage$caption) {
 
+    check_caption(caption)
+
     if (is.null(caption))
         caption <- ''
 
@@ -1021,6 +1023,7 @@ pandoc.table.return <- function(t, caption, digits = panderOptions('digits'), de
             res <- paste0(res, '\n\n')
 
         ## (optional) caption
+        check_caption(caption)
         if (!is.null(caption) && caption != '')
             res <- paste0(res, panderOptions('table.caption.prefix'), caption, '\n\n')
 
@@ -1062,7 +1065,7 @@ pandoc.formula.return <- function(x, text = NULL, max.width = 80, caption, add.l
     if (add.line.breaks)
         res <- paste(res, "\n\n")
     ## (optional) caption
-    if (!is.null(caption) && caption != '')
+    if (!is.null(caption) && caption != '' && check_caption(caption))
         res <- paste0(res, panderOptions('formula.caption.prefix'), caption, '\n\n')
     return(res)
 }

man/check_caption.Rd

@@ -0,0 +1,18 @@
+% Generated by roxygen2 (4.0.2): do not edit by hand
+\name{check_caption}
+\alias{check_caption}
+\title{Check if caption is valid}
+\usage{
+check_caption(caption)
+}
+\arguments{
+\item{caption}{R object to check}
+}
+\value{
+boolean
+}
+\description{
+Check if caption is valid
+}
+\keyword{internal}
+