Assignment – Working with XML and JSON in R

Pick three of your favorite books on one of your favorite subjects. At least one of the books should have more than one author. For each book, include the title, authors, and two or three other attributes that you find interesting.

Take the information that you’ve selected about these three books, and separately create three files which store the book’s information in HTML (using an html table), XML, and JSON formats (e.g. “books.html”, “books.xml”, and “books.json”). To help you better understand the different file structures, I’d prefer that you create each of these files “by hand” unless you’re already very comfortable with the file formats. Write R code, using your packages of choice, to load the information from each of the three sources into separate R data frames. Are the three data frame s identical?

Your deliverable is the three source files and the R code. If you can, package your assignment solution up into an .Rmd file and publish to rpubs.com. [This will also require finding a way to make your three text files accessible from the web].

library(knitr)
library(XML)
library(httr)
library(rjson)
library(RCurl)


HTML

html_url<-readHTMLTable(getURL("https://raw.githubusercontent.com/hovig/MSDS_CUNY/master/Data607/hw7/books.html"))
html_url<-lapply(html_url[[1]], function(x) {unlist(x)})
df.html<-as.data.frame(html_url)
kable(df.html)
title authors price publisher publishedDate type isbn_13_asin
Arabica Ohannes Ohannessian $7.99 CreateSpace Independent Publishing Platform October 1, 2014 Paperback 978-1502585455
Hebrew Phrasebook and Dictionary Justin Rudelson, Klara Ilana Wistinetzk $8.97 Lonely Planet March 15, 2013 Paperback 978-1741791389
Practical Textbook of Western Armenian (Self Teaching Armenian Language Method) Haroutiun Kurkjian $116.58 Armenian 2017 Paperback B003IGI1P4
is.data.frame(df.html)
## [1] TRUE

JSON

json_url<-fromJSON(file = "https://raw.githubusercontent.com/hovig/MSDS_CUNY/master/Data607/hw7/books.json")
json_url<-lapply(json_url[[1]], function(x) {unlist(x)})
df.json<-as.data.frame(do.call("rbind", json_url))
kable(df.json)
title authors price publisher publishedDate type isbn_13_asin
Arabica Ohannes Ohannessian $7.99 CreateSpace Independent Publishing Platform October 1, 2014 Paperback 978-1502585455
Hebrew Phrasebook and Dictionary Justin Rudelson, Klara Ilana Wistinetzk $8.97 Lonely Planet March 15, 2013 Paperback 978-1741791389
Practical Textbook of Western Armenian (Self Teaching Armenian Language Method) Haroutiun Kurkjian $116.58 Armenian 2017 Paperback B003IGI1P4
is.data.frame(df.json)
## [1] TRUE

XML

xml_url<-xmlInternalTreeParse(getURL("https://raw.githubusercontent.com/hovig/MSDS_CUNY/master/Data607/hw7/books.xml"))
xml_apply<-xmlSApply(xmlRoot(xml_url), function(x) xmlSApply(x, xmlValue))
df.xml<-data.frame(t(xml_apply), row.names = NULL)
kable(df.xml)
title authors price publisher publishedDate type isbn_13_asin
Arabica Ohannes Ohannessian $7.99 CreateSpace Independent Publishing Platform October 1, 2014 Paperback 978-1502585455
Hebrew Phrasebook and Dictionary Justin Rudelson, Klara Ilana Wistinetzk $8.97 Lonely Planet March 15, 2013 Paperback 978-1741791389
Practical Textbook of Western Armenian (Self Teaching Armenian Language Method) Haroutiun Kurkjian $116.58 Armenian 2017 Paperback B003IGI1P4
is.data.frame(df.xml)
## [1] TRUE

The three data frames are identical