Tag Archives: RApache

Comparing Shiny with gWidgetsWWW2.rapache

(A guest post by John Verzani)

A few days back the RStudio blog announced Shiny, a new product for easily creating interactive web applications (http://www.rstudio.com/shiny/). I wanted to compare this new framework to one I’ve worked on, gWidgetsWWW2.rapache – a version of the gWidgets API for use with Jeffrey Horner’s rapache module for the Apache web server (available at GitHub). The gWidgets API has a similar aim to make it easy for R users to create interactive applications.

I don’t want to worry here about deployment of apps, just the writing side. The shiny package uses websockets to transfer data back and forth from browser to server. Though this may cause issues with wider deployment, the industrious RStudio folks have a hosting program in beta for internet-wide deployment. For local deployment, no problems as far as I know – as long as you avoid older versions of internet explorer.

Now, Shiny seems well suited for applications where the user can parameterize a resulting graphic, so that was the point of comparison. Peter Dalgaard’s tcltk package ships with a classic demo tkdensity.R. I use that for inspiration below. That GUI allows the user a few selections to modify a density plot of a random sample.
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R Web Application – “Hello World” using RApache (~7min video tutorial)

I just noticed a google buzz from Jeroen ooms, with a Youtube video titled “RApache Hello World + POST arguments + catching errors.

In this ~7 min video tutorial, Jeroen shares with us:

  1. How to write ”Hello World” in a website using RApache.
  2. How to extract arguments from a form submited by the website visitor (and then inserting it into an “rnorm” function so to control the output). And finally,
  3. How to catch an error in case of an invalid argument on an R Web Application.

Thank you Jeroen for a very simple, step by step, tutorial:

p.s: For more videos by Jeroen, have a look at