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% File src/library/tools/man/Rd2HTML.Rd

% Part of the R package, https://www.R-project.org

% Copyright 2008-2018 R Core Team

% Distributed under GPL 2 or later

\name{Rd2HTML}

\alias{Rd2txt}

\alias{Rd2HTML}

\alias{Rd2ex}

\alias{Rd2latex}

\title{ Rd Converters }

\description{

  These functions take the output of \code{\link{parse_Rd}()}, an

  \code{Rd} object, and produce a help page from it.  As they are mainly

  intended for internal use, their interfaces are subject to change.

}

\usage{

Rd2HTML(Rd, out = "", package = "", defines = .Platform$OS.type,

        Links = NULL, Links2 = NULL,

        stages = "render", outputEncoding = "UTF-8",

        dynamic = FALSE, no_links = FALSE, fragment = FALSE,

        stylesheet = "R.css", ...)

Rd2txt(Rd, out = "", package = "", defines = .Platform$OS.type,

       stages = "render", outputEncoding = "",

       fragment = FALSE, options, ...)

Rd2latex(Rd, out = "", defines = .Platform$OS.type,

         stages = "render", outputEncoding = "UTF-8",

         fragment = FALSE, ..., writeEncoding = TRUE)

Rd2ex(Rd, out = "", defines = .Platform$OS.type,

      stages = "render", outputEncoding = "UTF-8",

      commentDontrun = TRUE, commentDonttest = FALSE, ...)

}

\arguments{

  \item{Rd}{ a filename or \code{Rd} object to use as input. }

  \item{out}{a filename or connection object to which to write the

    output.  The default \code{out = ""} is equivalent to

    \code{out = \link{stdout}()}.}

  \item{package}{ the package to list in the output. }

  \item{defines}{ string(s) to use in \verb{#ifdef} tests. }

  \item{stages}{ at which stage (\code{"build"}, \code{"install"}, or

    \code{"render"}) should \verb{\Sexpr} macros be executed? See the

    notes below.}

  \item{outputEncoding}{ see the \sQuote{Encodings} section below.}

  \item{dynamic}{logical: set links for render-time resolution by

      dynamic help system.}

  \item{no_links}{logical: suppress hyperlinks to other help topics.

      Used by \command{R CMD \link{Rdconv}}.}

  \item{fragment}{logical:  should fragments of Rd files be accepted?  See the

      notes below.}

  \item{stylesheet}{character: a URL for a stylesheet to be used in the header

      of the HTML output page.}

  \item{Links, Links2}{\code{NULL} or a named (by topics) character vector of

    links, as returned by \code{\link{findHTMLlinks}}.}

  \item{options}{An optional named list of options to pass to

    \code{\link{Rd2txt_options}}.}

  \item{...}{ additional parameters to pass to \code{\link{parse_Rd}} when

    \code{Rd} is a filename. }

  \item{writeEncoding}{should \verb{\inputencoding} lines be written in

      the file for non-ASCII encodings?}

  \item{commentDontrun}{should \verb{\dontrun} sections be commented

      out?}

  \item{commentDonttest}{should \verb{\donttest} sections be commented out?}

}

\details{

  These functions convert help documents: \code{Rd2HTML} produces HTML,

  \code{Rd2txt} produces plain text, \code{Rd2latex} produces LaTeX.

  \code{Rd2ex} extracts the examples in the format used by

  \code{\link{example}} and \R utilities.

  Each of the functions accepts a filename for an Rd file, and

  will use \code{\link{parse_Rd}} to parse it before applying the

  conversions or checks.

  The difference between arguments \code{Link} and \code{Link2} is that

  links are looked in them in turn, so lazy-evaluation can be used to

  only do a second-level search for links if required.

  Note that the default for \code{Rd2latex} is to output ASCII,

  including using the second option of \verb{\enc} markup.  This was

  chosen because use of UTF-8 in LaTeX requires version

  \sQuote{2005/12/01} or later, and even with that version the coverage

  of UTF-8 glyphs is not extensive (and not even as complete as

  Latin-1).

  \code{Rd2txt} will format text paragraphs to a width determined by

  \code{width}, with appropriate margins.  The default is to be close to

  the rendering in versions of \R < 2.10.0.

  \code{Rd2txt} will use directional quotes (see \code{\link{sQuote}})

  if option \code{"useFancyQuotes"} is true (the default) and

#ifdef unix

  the current encoding is UTF-8.

#endif

#ifdef windows

  the current locale uses a single-byte encoding (except C).

  (Directional quotes are not attempted in East Asian locales as they are

  usually double-width, which looks wrong with English text.)

#endif

  Various aspects of formatting by \code{Rd2txt} are controlled by the

  \code{options} argument, documented with the \code{\link{Rd2txt_options}}

  function.  Changes made using \code{options} are temporary, those

  made with \code{\link{Rd2txt_options}} are persistent.

  When \code{fragment = TRUE}, the \code{Rd} file will be rendered

  with no processing of \verb{\Sexpr} elements or conditional defines

  using \verb{#ifdef} or \verb{#ifndef}.  Normally a fragment represents

  text within a section, but if the first element of the fragment

  is a section macro, the whole fragment will be rendered as

  a series of sections, without the usual sorting.

}

\section{Encodings}{

  Rd files are normally intended to be rendered on a wide variety of

  systems, so care must be taken in the encoding of non-ASCII

  characters.  In general, any such encoding should be declared using

  the \samp{encoding} section for there to be any hope of correct

  rendering.

  For output, the \code{outputEncoding} argument will be used:

  \code{outputEncoding = ""} will choose the native encoding for the

  current system.

  If the text cannot be converted to the \code{outputEncoding}, byte

  substitution will be used (see \code{\link{iconv}}): \code{Rd2latex}

  and \code{Rd2ex} give a warning.

}

\note{

  The \verb{\Sexpr} macro is a new addition to Rd files.  It includes

  \R code that will be executed at one of three times: \emph{build} time

  (when a package's source code is built into a tarball),

  \emph{install} time (when the package is installed or

  built into a binary package), and \emph{render} time (when the man

  page is converted to a readable format).

  For example, this man page was:

  \enumerate{

    \item built on

    \Sexpr[stage=build]{format(Sys.time(), "\%Y-\%m-\%d at \%H:\%M:\%S")},

    \item installed on

    \Sexpr[stage=install]{format(Sys.time(), "\%Y-\%m-\%d at \%H:\%M:\%S")}, and

    \item rendered on

    \Sexpr[stage=render]{format(Sys.time(), "\%Y-\%m-\%d at \%H:\%M:\%S")}.

  }

}

\value{

  These functions are executed mainly for the side effect of

  writing the converted help page.  Their value is the name of the output

  file (invisibly).  For \code{Rd2latex}, the output name is given an

  attribute \code{"latexEncoding"} giving the encoding of the file in a

  form suitable for use with the LaTeX \samp{inputenc} package.

}

\author{

  Duncan Murdoch, Brian Ripley

}

\references{ \url{https://developer.r-project.org/parseRd.pdf} }

\seealso{

  \code{\link{parse_Rd}}, \code{\link{checkRd}},

  \code{\link{findHTMLlinks}}, \code{\link{Rd2txt_options}}.

}

\examples{\donttest{

\dontrun{

## Simulate install and rendering of this page in HTML and text format:

Rd <- file.path("src/library/tools/man/Rd2HTML.Rd")

outfile <- tempfile(fileext = ".html")

browseURL(Rd2HTML(Rd, outfile, package = "tools",

          stages = c("install", "render")))

outfile <- tempfile(fileext = ".txt")

file.show(Rd2txt(Rd, outfile, package = "tools",

          stages = c("install", "render")))

checkRd(Rd) # A stricter test than Rd2HTML uses

}}}

\keyword{ documentation }