Introduction

For this assignment I chose 3 favorite books in a topic and created 3 equivalent tables in HTML, XML, and JSON. The topic was city infrastructure.

Load Packages

suppressWarnings(library(knitr))
suppressWarnings(library(plyr))
suppressMessages(suppressWarnings(library(RCurl)))
suppressWarnings(library(htmltab))
suppressWarnings(library(XML))
suppressWarnings(library(xtable))
suppressWarnings(library(jsonlite))

Import HTML

urlhtml<-"https://raw.githubusercontent.com/spsstudent15/2016-01-607-08/master/books.html"
filehtml<-getURL(url=urlhtml)
thtml<-htmltab(doc=filehtml)

## Argument 'which' was left unspecified. Choosing first table.

## Neither <thead> nor <th> information found. Taking first table row for the header. If incorrect, specifiy header argument.

kable(thtml)

	Title	Author	Year	Reading Level	Genre
2	The Power Broker	Robert Caro	1974	Adult	History
3	The Works: Anatomy of a City	Kate Ascher	2007	Young Adult	Engineering
4	Building Construction: Principles, Materials, and System	Madan Mehta, Walter R. Scarborough, Diane Armpriest	2012	Adult	Engineering

Import XML

urlxml<-"https://raw.githubusercontent.com/spsstudent15/2016-01-607-08/master/books.xml"
filexml<-getURL(urlxml)
dfxml<-ldply(xmlToList(filexml),data.frame)
kable(dfxml)

.id	title	author	year	readinglevel	genre	.attrs
book	The Power Broker	Robert Caro	1974	Adult	History	1
book	The Works: Anatomy of a City	Kate Ascher	2007	Young Adult	Engineering	2
book	Building Construction: Principles, Materials, and Systems	Madan Mehta, Walter R. Scarborough, Diane Armpriest	2012	Adult	Engineering	3

Import JSON

urljson<-"https://raw.githubusercontent.com/spsstudent15/2016-01-607-08/master/books3.json"
filejson<-getURL(url=urljson)
tjson<-fromJSON(filejson)
kable(tjson)

title	author	year	readinglevel	genre
The Power Broker	Robert Caro	1974	Adult	History
The Works: Anatomy of a City	Kate Ascher	2007	Young Adult	Engineering
Building Construction: Principles, Materials, and Systems	Madan Mehta, Walter R. Scarborough, Diane Armpriest	2012	Adult	Engineering

Conclusion

The tables were slightly different. The HTML table added an index row. The XML table added a column for the table ID name, and also added an .attrs column for row count. The JSON seemed to make no changes to the intended table.