Interactive Slide Decks

[ramnathv]

I have pared down interactive slide decks to their bare minimum. A few more things that remain.

Hooks

Currently, the following code needs to be inserted into every interactive slide deck. I want to figure out an elegant way by which this can be made the default for interactive slides. One way is to extend the idea of a widget to R files that are sourced before slidifying. So for example, config.yml can contain a link to an R file that gets sourced in a local environment.

```{r setup, echo = F, cache = F, tidy = F}
knit_hooks$set(source = function(x, options){
  if (!is.null(options$interactive) && (options$interactive)){
    paste0("<textarea class='interactive' id='interactive{{slide.num}}' 
       data-cell='{{slide.num}}' data-results='", 
       options$results, "' style='display:none'>", 
      x, "</textarea>")
  } else {
    stringr::str_c("\n\n```", tolower(options$engine), "\n", x, "```\n\n")
  }
})
opts_chunk$set(tidy = FALSE, eval = FALSE, interactive = TRUE, results = 'asis')

[ramnathv]

Here is more code in server.R that needs to be packaged for easy reuse. Some are utility functions, while some need to be in shinyServer

require(shiny)
.slidifyEnv = new.env()
runCode <- function(code){
  require(knitr)
  chunk = paste('```{r echo = F,message = F, comment = NA, results = "asis"}\n', 
   code, "\n```", collapse = '\n')
  out = knit(text = chunk, envir = .slidifyEnv)
  markdown::markdownToHTML(text = out, fragment = TRUE)
}

# Function to dynamically extract cell numbers for all interactive cells
getCells <- function(){
  require(XML)
  doc = htmlParse('www/index.html')
  cells = getNodeSet(doc, '//textarea')
  as.numeric(sapply(cells, xmlGetAttr, 'data-cell'))
}

make_opencpu_version = function(){
  doc = paste(readLines('www/index.html', warn = F), collapse = '\n')
  doc = gsub('action-button', 'iBtn', doc, fixed = TRUE)
  doc = gsub('libraries/', 'www/libraries/', doc, fixed = TRUE)
  doc = gsub('./assets/', 'www/assets/', doc, fixed = TRUE)
  cat(doc, file = 'index.html')
}

shinyServer(function(input, output, session){
  print('Running Server')
  cells = getCells()
  invisible(lapply(cells, function(i){
    output[[paste0('knitResult', i)]] <- reactive({
      if (input[[paste0('runCode', i)]] != 0)
        return(isolate({
          print('running code')
          runCode(input[[paste0('interactive', i)]])
        }))
    })
    outputOptions(output, paste0('knitResult', i), suspendWhenHidden = F)
  }))
})

[ramnathv]

It would be nice if I can use runApp and specify ui and server as functions. It would then be possible to write a function that would automagically add these things.

[ramnathv]

This is DONE in the dev version.