We are required to load 3 files: HTML, XLS, and JSON.

File #1 - HTML

We will read an HTML file from github

URL <- "https://raw.githubusercontent.com/mgroysman/Data-607-Upload-Assignment-Week-7/master/Books.html"

destfile <- "C://Data/temp.html"

download.file(URL, destfile)

#install.packages("XML")

library(XML)

html_data<-readHTMLTable(destfile)

html_data
## $`NULL`
##                                                          Title
## 1                                          The Language of SQl
## 2                                 SQL Queries for Mere Mortals
## 3 Sam Teach Yourself. Microsoft SQL Server T-SQL in 10 Minutes
##                Author1         Author2             Publisher
## 1        Larry Rockoff                 Course Technology PTR
## 2 Michael J. Hernandez John L. Viescas        Addison-Wesley
## 3            Ben Forta                     Pearson Education
##             CountryPrinted
## 1 United States of America
## 2 United States of America
## 3 United States of America
typeof(html_data)
## [1] "list"

File #2 - XML

We will read a XML file from github

URL <- "https://raw.githubusercontent.com/mgroysman/Data-607-Upload-Assignment-Week-7/master/Books.xml"

destfile <- "C://Data/temp.xml"

download.file(URL, destfile)

#install.packages("plyr")

library(plyr)

xml_data<- ldply(xmlToList(destfile), data.frame)

xml_data
##     .id                                                        Title
## 1 Books                                          The Language of SQl
## 2 Books                                 SQL Queries for Mere Mortals
## 3 Books Sam Teach Yourself. Microsoft SQL Server T-SQL in 10 Minutes
##                Author1         Author2               Publisher
## 1        Larry Rockoff                   Course Technology PTR
## 2 Michael J. Hernandez John L. Viescas          Addison-Wesley
## 3            Ben Forta                 Pearson Education, Inc.
##             CountryPrinted .attrs
## 1 United States of America      1
## 2 United States of America      2
## 3 United States of America      3

File #3 - JSON

We will read a Json file from github

URL <- "https://raw.githubusercontent.com/mgroysman/Data-607-Upload-Assignment-Week-7/master/Books.json"

destfile <- "C://Data/temp.json"

download.file(URL, destfile)

#install.packages("RJSONIO")

library("RJSONIO")

isValidJSON(destfile)
## [1] TRUE
json_data<- fromJSON(destfile,nullValue=NA,simplify=FALSE)

json_data1<-do.call("rbind",lapply(json_data,data.frame,stringsAsFactors=FALSE))

json_data1
##                                                          Title
## 1                                          The Language of SQl
## 2                                 SQL Queries for Mere Mortals
## 3 Sam Teach Yourself. Microsoft SQL Server T-SQL in 10 Minutes
##                Author1         Author2             Publisher
## 1        Larry Rockoff                 Course Technology PTR
## 2 Michael J. Hernandez John L. Viescas        Addison-Wesley
## 3            Ben Forta                     Pearson Education
##               PrintCountry
## 1 United States of America
## 2 United States of America
## 3 United States of America

All 3 dataframes captured the data. I personally prefer JSON dataframe. I do not have to deal with factors and it does not have additional attributes as XML one.