Rdevel <- "~/R/r-devel/BUILD/bin/Rscript"
R <- "/usr/bin/Rscript"
R2.15.3 <- "/scratch/R-releases/R-2.15.3/bin/R"
R3.0.0 <- "/scratch/R-releases/R-3.0.0/bin/R"
    
library(whisker)
templateRhtml <- readLines("template.Rhtml")
templateOldRhtml <- readLines("template-old-R-version.Rhtml")

# Function to ...
#
#   generate .Rhtml fragment from 'code',
#   run R (as specified by 'r'),
#   knit the .Rhtml fragment, then
#   return the knitted HTML fragement,
#     with wrapper HTML reporting the R version
#     and the plot produced by the .Rhtml fragment
#
#   echo=TRUE means that the code will be shown
#   eval=TRUE means that the code will be run
#   fig=TRUE means that the code will (also) be run to generate SVG output
#   DEFAULT is to show code, NOT run the code, and generate SVG

Rsession <- function(r, label, code, echo=TRUE, eval=FALSE, fig=TRUE) {
    # Generate .Rhtml doc from code
    data <- list(label=label, code=code,
                 echo=echo, eval=eval, figeval=fig)
    writeLines(whisker.render(templateRhtml, data), 
               paste0(label, ".Rhtml"))
    system(paste(r,
                 paste0("-e 'library(\"knitr\"); knit(\"",
                        label, ".Rhtml\")'")),
           ignore.stdout=TRUE, ignore.stderr=TRUE)
    if (fig) {
        figureHTML <- paste0('<img width="100" src="', label, '.svg"/>')
    } else {
        figureHTML <- ""
    }
    html <- c('<table class="Rsession">',
              '<tr><td class="Rsession-version">',
              readLines("version.txt", warn=FALSE),
              '</td></tr>',
              '<tr><td class="Rsession-chunk">',
              readLines(paste0(label, ".html")),
              '</td>',
              '<td class="Rsession-image">',
              figureHTML,
              '</td>',
              '</table>')
    cat(html, sep="\n")
}

# Function to ...
#   cat code to file
#   BATCH run file in old R version 
#   generate .Rhtml with just echoed code and echoed output
#   knit the .Rhtml with current R

#   WILL ONLY WORK for very simple script with single output

oldRsession <- function(r, label, code) {
    writeLines(c("pdf()", paste0('sink("', label, '.out")'), code),
               paste0(label, ".R"))
    writeLines('sink("version.out")\ncat(R.version.string)', "version.R")
    system(paste0(r, "script ", label, ".R"))
    system(paste0(r, "script version.R"))
    output <- paste(readLines(paste0(label, ".out"), warn=FALSE), collapse="\n")
    data <- list(code=code, output=output)
    writeLines(whisker.render(templateOldRhtml, data), 
               paste0(label, ".Rhtml"))
    system(paste(R,
                 paste0("-e 'library(\"knitr\"); knit(\"",
                        label, ".Rhtml\")'")),
           ignore.stdout=TRUE, ignore.stderr=TRUE)
    html <- c('<table class="Rsession">',
              '<tr><td class="Rsession-version">',
              readLines("version.out", warn=FALSE),
              '</td></tr>',
              '<tr><td class="Rsession-chunk">',
              readLines(paste0(label, ".html")),
              '</td>',
              '<td class="Rsession-image">',
              '</td>',
              '</table>')
    cat(html, sep="\n")    
}