Embedding R In A Website
I wanted to know whether/how it is possible to embed R in a website. Looking around the internet I found a few interesting initiatives, each one dedicated to a slightly different purpose: RStudio, Shiny, Jupyter Notebook, RApache, OpenCPU and RAppArmor.
RStudio is probably very well known among R programmers. According to its website, RStudio is an integrated development environment. One of the best features of RStudio in my eyes is the ability to create both markdown and HTML pages, that contain executable R code. If you are familiar with [IPython notebook] then this is nothing new for you. In this way you can easily create protocols of your work, share them with colleagues and publish them in a webpage.
RStudio comes both as a standalone desktop edition and a server edition for projects of bigger scale. Both desktop and server are available as a free open source product and as a commercially licensed product.
Shiny I found pretty exciting. It is essentially a web application framework that lets you build interactive web apps quickly and easily without having to have extensive web programming skills. You can either run your Shiny websites in your own web server or use the cloud hosting service provided by the vendor.
Shiny is developed by the same company that sells RStudio. The open source version of Shiny can be obtained through this GitHub page. I believe there’s also a cloud where you can upload your R web apps.
Jupyter Notebook looks very impressive to me. Being essentially an extension of the already mentioned IPython Notebook (and thus requiring Python to run) you can write research reports easily, mix comments with executable code etc. Besides Python and R many more languages are supported like Scala, Julia or Haskell.
rApache enables you to run R inside your Apache web server in a script-like fashion. rApache distributes the Apache module mod_R for this purpose. Therefore you have a neat integration of R with the probably most relevant open source web server. It’s not entirely clear to me how secure this is, therefore you should probably take the usual precautions before opening a webpage to the whole world that lets the users execute such code on your server.
OpenCPU is both an API plus server. On the one hand, it defines a REST-API that enables you to call R code on any server implementing this standard. As it is RESTful, you can easily create HTTP requests executing your R commands in an intuitive way. On the other hand, OpenCPU is also a server. The server can be set up on top of for example rApache or RStudio server. It handles object serialization, security, resource control and more. An overview on OpenCPU was published in this paper on arxiv.org, there is also a slide show giving a summary.
RAppArmor is a [CRAN package] that aims at securing your R execution engine. Whereas the concept of sandboxing has existed for example for the Java Virtual Machine already from the beginning, the same is not the case for R. As soon as you run R on the server and open it up for the rest of the world, you of course would like to have a certain level of control over resources and execution rights. RAppArmor was built for this purpose.
Then, of course, there are the cloud providers.
R-Fiddle is an online R. The really cool thing is that you can write some code and then embed it in your own webpage in a HTML iframe. This is maybe the fastest and easiest way of embedding R in a webpage. Of course there are limitations to what can be done, but for not too complicated examples this should work just fine. Also see this blog post on R-Fiddle.
A website similar to R-Fiddle, that however requires setting up a username & password, is DataJoy. You can write online scripts with R or Python.
SageMath apparently is similar to DataJoy. You’ll need to register with your name, create a username and password before you’re able to write R code in your browser and run it in the remote cloud.
A fourth alternative is provided by Tutorials Point. However, I did not easily spot how to create plots, and typing commands in the shell seemed to be rather slow.
Of course there’s even more going on with projects like rpy2 or Rocker, but most of them do not explicitly target integration with the web. Also of interest is perhaps Analog Sea for Digital Ocean. Analog Sea is freeware, however Digital Ocean is not. Digital Ocean is a commercial online computing cloud. You can create and destroy so called “droplets” (remote virtual computers) that execute your code. It’s thus somewhat similar to the Amazon Cloud. Then there are free online courses to learn R offered by DataCamp or Code School.