Markdown preview via shiny, pandoc and pander

meme.jpg

server.R

library(shiny)
library(pander)

shinyServer(function(input, output) {

    output$html = reactive({

        ## convert input to html
        t <- Pandoc.convert(
            text    = input$markdown,
            format  = 'html',
            open    = FALSE,
            options = '-s')

        ## read results
        res <- readLines(t)

        ## cleanup
        unlink(sub('.html$', '*', t))

        ## return
        paste(res, collapse = '\n')

    })

})

ui.R

library(shiny)

shinyUI(fluidPage(

    titlePanel('Try markdown'),

    fluidRow(
        column(6,
               tags$textarea(
                   'Hello markdown!',
                   id    = 'markdown',
                   rows  = 25,
                   style = 'width:100%;')),

        column(6,
            htmlOutput('html')))

))

rmarkdown version: https://gist.github.com/daroczig/2812971d0c2613ceb669