Secret to Making Things Appear in RStudio Viewer

I am by no means an authoritative source on this, but I think I found out the secret behind htmltools html_print that chooses the RStudio Viewer browser rather than your default browser like utils::browseURL. Here is a quick code snippet that hopefully explains what is happening. It appears you just need a temp directory with the pattern starting with viewhtml*.

library(htmltools)
library(pipeR)

# htmltools from RStudio very nicely
# makes things appear in the Viewer Window
"<h3>Hello in RStudio Viewer</h3>" %>>%
  HTML %>>%
  html_print


# there is a little secret to doing the same
# without htmltools
"<h3>Hello in RStudio Viewer</h3>" %>>%
  HTML %>>%
  # and the secret is to place in a temp directory
  # with the pattern viewhtml
  (
  ht ~
    tempfile("viewhtml") %>>%
    (~ dir.create(.) ) %>>%
    (~ save_html(ht, file = file.path(.,"index.html")) ) %>>%
    ( getOption("viewer")(file.path(.,"index.html")) )
  )
  
# to see it in action look at the code change
# in this project
utils::browseURL("https://github.com/bryanhanson/exCon/pull/1/files")

The only reason I mention it is that I much prefer to stay in the RStudio environment instead of switching contexts to a browser.  I still firmly recommend using tags from htmltools as the best method to make all this work seamlessly and as intended by the experts at RStudio. 

Postive Feedback in R with a Little Javascript

Let’s face it, sometimes the struggle in R can become frustrating, depressing, daunting, or just monotonous.  For those moments when you need a little positive feedback, some encouragement, or a pat on the back, I thought this might help.  Maybe I should make this into a package.

I found this from Sweet Alert for Bootstrap forked from Tristan Edwards non-bootstrap SweetAlert.  This builds on the technique used in my previous post SVG + a little extra (d3.js) in RStudio Browser | No Pipes This Time.

 

# give yourself some positive feedback in R
# as you toil away on some difficult, but worthwhile task
# uses javascript sweet-alert https://github.com/t4t5/sweetalert

library(htmltools)
library(pipeR)

tagList(
  tags$script(
    '
    document.addEventListener("DOMContentLoaded", function(event) { 
      swal("Good job! Brilliant!", "You\'re doing worthwhile things.", "success")
    });
    '
  )
) %>>%
  attachDependencies(
    htmlDependency(
      name="sweet-alert"
      ,version="0.2.1"
      ,src=c("href"=
               "http://timelyportfolio.github.io/sweetalert/lib"
      )
      ,script = "sweet-alert.min.js"
      ,style = "sweet-alert.css"
    )
  ) %>>%
  html_print

Unbelievable and Amazing R Shiny–Web Parameter Test in 1.5 Hours

Life keeps getting better and better.  Yesterday, I discovered the absolutely unbelievable and amazing work RStudio has done with Shiny employing one of my favorite R packages websockets.  As proof of the ease and quality, within a couple of minutes, I was able to get it up and running.  This morning basically starting from scratch in less than 1.5 hours I was able to achieve a web-based interactive parameter test for a moving average system as my first example.

Below is a screencast of this very basic parameter testing web app.  I can only hope that this simple application can illustrate just how powerful Shiny is.  Just imagine pairing this with d3 or knitr.

R code for server.R and ui.R from GIST: