Assigment7 - 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 frames 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(stringr)
library(XML) #for xml files processing
library(RCurl)
library(rvest)  # my favorite
library(dplyr)
library(jsonlite) # for json files processing
library("kableExtra") # for beautify dataframes display


# to get rid of the scientific notation for ISBN long number and leave it as character, we include the folling option:
options(scipen=999) 
#without this option on, the ISBN of our books will be presented in a scientific notation, i.e. with exponential display

Loading from an HTML file that has an html table inside it

url <- "https://raw.githubusercontent.com/theoracley/Data607/master/Assignment7/mybooks.html"

#first method
# theURL <- getURL(url)
# myTable <- readHTMLTable(theURL, header=TRUE, which=1)
# myTable


# #second Method (more work)
# page <- read_html(url)
# tables <- html_nodes(page, "table")
# myTable <- html_table(tables[1], fill = NA)
# myTable[[1]]


#third method
myTable <- read_html(url)
htmlBookDS <- myTable %>%
  html_nodes("table") %>%
  .[[1]] %>%
  html_table(fill = NA) # html_table converts data to an R data frame automatically

colnames(htmlBookDS) <- c("Title", "Authros", "Publisher","Published Date", "ISBN")
#htmlBookDS
#beautify the display
htmlBookDS  %>%
  kable() %>%
  kable_styling(bootstrap_options = c("striped", "hover", "condensed")) %>%
  scroll_box(width = "100%", height = "200px")

Title	Authros	Publisher	Published Date	ISBN
AI for People and Business	Alex Castrounis	O’Reilly Media, Inc	July 2019	9781492036579
Own the A.I. Revolution	Michael Ashley, Neil Sahota	McGraw-Hill	May 2019	9781260458381
Machine Learning and AI for Healthcare	Arjun Panesar	Apress	February 2019	9781484237991

Loading from an xml file

url <- "https://raw.githubusercontent.com/theoracley/Data607/master/Assignment7/mybooks.xml"
 
xmlData <- read_xml(url)
aiBooks <- xml_children(xmlData)

xmlBookDS <- c()
for (i in 1:length(aiBooks)){
  xmlBookDS <- rbind(xmlBookDS,xml_text(xml_children(aiBooks[i])))
}

xmlBookDS <- data.frame(xmlBookDS)

colnames(xmlBookDS) <- xml_name(xml_children(aiBooks[1]))
#xmlBookDS

#beautify the display
xmlBookDS  %>% 
  kable() %>% 
  kable_styling(bootstrap_options = c("striped", "hover", "condensed")) %>%
  scroll_box(width = "100%", height = "200px")

title	authors	publisher	published_date	isbn
AI for People and Business	Alex Castrounis	O’Reilly Media, Inc	July 2019	9781492036579
Own the A.I. Revolution	Michael Ashley, Neil Sahota	McGraw-Hill	May 2019	9781260458381
Machine Learning and AI for Healthcare	Arjun Panesar	Apress	February 2019	9781484237991

Loading from a json file

url <- "https://raw.githubusercontent.com/theoracley/Data607/master/Assignment7/mybooks.json"

#fromJSON method converts any json object to an R data frame.
jsonBookDS <- fromJSON(url)
#jsonBookDS

#beautify the display
jsonBookDS  %>% 
  kable() %>% 
  kable_styling(bootstrap_options = c("striped", "hover", "condensed")) %>%
  scroll_box(width = "100%", height = "200px")

title	authors	publisher	published date	isbn
AI for People and Business	Alex Castrounis	O’Reilly Media, Inc	July 2019	9781492036579
Own the A.I. Revolution	Michael Ashley, Neil Sahota	McGraw-Hill	May 2019	9781260458381
Machine Learning and AI for Healthcare	Arjun Panesar	Apress	February 2019	9781484237991

Conclusion:

As we can see, all datasets created from html, xml and json files have exactly the same resulting dataframes. While all 3 files have different structures , they all yield the same resulting dataframes when choosing special package for each file type.