Adding cell_spec
diff --git a/R/cell_spec.R b/R/cell_spec.R
new file mode 100644
index 0000000..f5bff2a
--- /dev/null
+++ b/R/cell_spec.R
@@ -0,0 +1,89 @@
+#' Specify Cell format
+#'
+#' @description Specify Cell format before it gets into kable
+#'
+#' @param x Things to be formated. It could be a vector of numbers or strings.
+#' @param format Either "html" or "latex". It can also be set through
+#' `option(knitr.table.format)`, same as `knitr::kable()`.
+#' @param bold A T/F value to control whether the text of the selected column
+#' need to be bolded.
+#' @param italic A T/F value to control whether the text of the selected column
+#' need to be emphasized.
+#' @param monospace A T/F value to control whether the text of the selected column
+#' need to be monospaced (verbatim)
+#' @param color A character string for column text color. Here please pay
+#' attention to the differences in color codes between HTML and LaTeX.
+#' @param background A character string for column background color. Here please
+#' pay attention to the differences in color codes between HTML and LaTeX.
+#' @param align A character string for cell alignment. For HTML, possible values could
+#' be `l`, `c`, `r` plus `left`, `center`, `right`, `justify`, `initial` and `inherit`
+#' while for LaTeX, you can only choose from `l`, `c` & `r`.
+#' @param font_size Only if you want to specify font size locally in HTML.
+#' This feature is not available in LaTeX
+#' @param angle 0-360, degree that the text will rotate.
+#'
+#' @export
+cell_spec <- function(x, format,
+                      bold = F, italic = F, monospace = F,
+                      color = NULL, background = NULL,
+                      align = NULL, font_size = NULL, angle = NULL) {
+
+  if (missing(format) || is.null(format)) format = getOption('knitr.table.format')
+  if (is.null(format)) {
+    warning("Output format for cell_formatter was not specified. Using ",
+            "html as default. You may consider to set it up via option knitr.table.format.",
+            "See ?cell_formatter for details. ")
+    return(x)
+  }
+
+  if (tolower(format) == "html") {
+    return(cell_spec_html(x, bold, italic, monospace,
+                          color, background, align, font_size, angle))
+  }
+  if (tolower(format) == "latex") {
+    return(cell_spec_latex(x, bold, italic, monospace,
+                           color, background, align, angle))
+  }
+}
+
+cell_spec_html <- function(x, bold, italic, monospace,
+                           color, background, align, font_size, angle) {
+  cell_style <- NULL
+  if (bold) cell_style <- paste(cell_style,"font-weight: bold;")
+  if (italic) cell_style <- paste(cell_style, "font-style: italic;")
+  if (monospace) cell_style <- paste(cell_style, "font-family: monospace;")
+  if (!is.null(color)) cell_style <- paste0(cell_style, " color: ", color, ";")
+  if (!is.null(background)) {
+    cell_style <- paste0(cell_style, " border-radius: 4px; padding-right: 2px",
+                         "; background-color: ", background, ";")
+  }
+  if (!is.null(align)) {
+    cell_style <- paste0(cell_style, " text-align: ", align, ";")
+  }
+  if (!is.null(font_size)) {
+    cell_style <- paste0(cell_style, " font-size: ", font_size, "px;")
+  }
+  if (!is.null(angle)) {
+    cell_style <- paste0(cell_style,
+                         " -webkit-transform: rotate(", angle,
+                         "deg); -moz-transform: rotate(", angle,
+                         "deg); -ms-transform: rotate(", angle,
+                         "deg); -o-transform: rotate(", angle, "deg);")
+  }
+  out <- paste0(
+    '<div style="', cell_style, '">', x, '</div>'
+  )
+  return(out)
+}
+
+cell_spec_latex <- function(x, bold, italic, monospace,
+                            color, background, align, angle) {
+  if (bold) x <- paste0("\\bfseries{", x, "}")
+  if (italic) x <-paste0("\\em{", x, "}")
+  if (monospace) x <- paste0("\\ttfamily{", x, "}")
+  if (!is.null(color)) x <- paste0("\\textcolor{", color, "}{", x, "}")
+  if (!is.null(background)) x <- paste0("\\cellcolor{", background, "}{", x, "}")
+  if (!is.null(align)) x <- paste0("\\multicolumn{1}{", align, "}{", x, "}")
+  if (!is.null(angle)) x <- paste0("\\rotatebox{", angle, "}{", x, "}")
+  return(x)
+}