Improve RWordPress allowing proper code highlight when using Crayon.

R/knit2wpCrayon.R

+#' @title knit to wordpress that uses crayon sintax highlight
+#'
+#' @name knit2wpCrayon
+#'
+#' @description This function improves the \code{RWordPress::knit2wp} to
+#'     allow properly render code when using Crayon Sintax Highlighter.
+#'
+#' @param input a markdown or Rmarkdown file.
+#' @param title title for the post.
+#' @param ... other meta information of the post. See
+#      \link[RWordPress]{knit2wp}.
+#' @param action indicates a new post, a edition of the post or a new
+#'     page.
+#' @param postid number of the post.
+#' @param encoding ht encoding of the input file.
+#' @param upload logical, if the file is to be updated to the blog.
+#' @param publish logical, if the post is to be published or stay in
+#'     draft mode.
+#' @param write logical, is the result of knit be written to a html
+#'     file. This is useful to copy from this file and paste inside the
+#'     wordpress post editor (on text mode, not visual mode).
+#'
+#' @return None is returned by the function.
+#'
+#' @author Walmes Zeviani, \email{walmes@@ufpr.br}
+#'
+#' @import knitr RWordPress
+#' @export
+#' @examples
+#' \donttest{
+#'
+#' library(knitr)
+#' library(RWordPress)
+#' 
+#' post <- "2015-08-24_polyGui.Rmd"
+#' title <- "Interface para regressão polinomial"
+#' categ <- c("gui", "rbloggers_pt")
+#' keywd <- c("gWdigets", "legTools", "lm", "poly")
+#' 
+#' pass <- scan(n=1, what=character())
+#' options(WordpressLogin=c(walmes=pass),
+#'         WordpressURL="http://blog.leg.ufpr.br/xmlrpc.php")
+#' 
+#' knit2wpCrayon(post, title=title,
+#'               action="editPost", postid=179,
+#'               categories=categ, mt_keywords=keywd,
+#'               ## write=TRUE, upload=FALSE,
+#'               write=FALSE, upload=TRUE,
+#'               publish=FALSE)
+#' 
+#' }
+knit2wpCrayon <- function(input, title="A post from knitr", ...,
+                          action=c("newPost", "editPost", "newPage"),
+                          postid, encoding=getOption("encoding"),
+                          upload=FALSE, publish=FALSE, write=TRUE){
+    out <- knit(input, encoding=encoding)
+    on.exit(unlink(out))
+    con <- file(out, encoding=encoding)
+    on.exit(close(con), add=TRUE)
+    content <- knitr:::native_encode(readLines(con, warn=FALSE))
+    content <- paste(content, collapse="\n")
+    content <- markdown::markdownToHTML(text=content, fragment.only=TRUE)
+    content <- gsub(
+        pattern="<pre><code class=\"([[:alpha:]]+)\">(.+?)</code></pre>",
+        replacement="<pre class=\"lang:\\1 decode:true\">\\2</pre>",
+        x=content)
+    content=knitr:::native_encode(content, "UTF-8")
+    title=knitr:::native_encode(title, "UTF-8")
+    if (write){
+        writeLines(text=content,
+                   con=gsub(x=out, pattern="\\.md$", replacement=".html"))
+    }
+    if (upload){
+        action=match.arg(action)
+        WPargs=list(content=list(description=content, title=title, 
+                        ...), publish=publish)
+        if (action=="editPost") 
+            WPargs=c(postid=postid, WPargs)
+        do.call("library", list(package="RWordPress", character.only=TRUE))
+        print(do.call(action, args=WPargs))
+    }
+}