Getting data into R from web APIs using the httr R package

We need to implement the following steps to extract data using the httr package in R workspace:

First, we load the httr package:

library(httr)

We then call GET function and pass it as a URL:

r <- GET("http://httpbin.org/get")

This gives us a response object that can be processed further for data. To start with, we can print out the response object to get some information about the data:

>r
Response [http://httpbin.org/get]
  Date: 2019-01-18 03:45
  Status: 200
  Content-Type: application/json
  Size: 326 B
{
  "args": {}, 
  "headers": {
    "Accept": "application/json, text/xml, application/xml, */*", 
    "Accept-Encoding": "gzip, deflate", 
    "Connection": "close", 
    "Host": "httpbin.org", 
    "User-Agent": "libcurl/7.58.0 r-curl/3.2 httr/1.3.1"
  }, 
  "origin": "106.200.254.84", 
...

We can get to the data contained in the response using the content method. For example, to get the body of the request as a raw vector, the following command is executed:

> content(r, "raw")
  [1] 7b 0a 20 20 22 61 72 67 73 22 3a 20 7b 7d 2c 20 0a 20 20 22 68 65 61 64 65 72 73 22 3a 20
 [31] 7b 0a 20 20 20 20 22 41 63 63 65 70 74 22 3a 20 22 61 70 70 6c 69 63 61 74 69 6f 6e 2f 6a
 [61] 73 6f 6e 2c 20 74 65 78 74 2f 78 6d 6c 2c 20 61 70 70 6c 69 63 61 74 69 6f 6e 2f 78 6d 6c
 [91] 2c 20 2a 2f 2a 22 2c 20 0a 20 20 20 20 22 41 63 63 65 70 74 2d 45 6e 63 6f 64 69 6e 67 22
[121] 3a 20 22 67 7a 69 70 2c 20 64 65 66 6c 61 74 65 22 2c 20 0a 20 20 20 20 22 43 6f 6e 6e 65
[151] 63 74 69 6f 6e 22 3a 20 22 63 6c 6f 73 65 22 2c 20 0a 20 20 20 20 22 48 6f 73 74 22 3a 20
[181] 22 68 74 74 70 62 69 6e 2e 6f 72 67 22 2c 20 0a 20 20 20 20 22 55 73 65 72 2d 41 67 65 6e
[211] 74 22 3a 20 22 6c 69 62 63 75 72 6c 2f 37 2e 35 38 2e 30 20 72 2d 63 75 72 6c 2f 33 2e 32
[241] 20 68 74 74 72 2f 31 2e 33 2e 31 22 0a 20 20 7d 2c 20 0a 20 20 22 6f 72 69 67 69 6e 22 3a
[271] 20 22 31 30 36 2e 32 30 30 2e 32 35 34 2e 38 34 22 2c 20 0a 20 20 22 75 72 6c 22 3a 20 22
[301] 68 74 74 70 3a 2f 2f 68 74 74 70 62 69 6e 2e 6f 72 67 2f 67 65 74 22 0a 7d 0a
> 

In the next section, we will learn to get data into R by scraping the web using the rvest package.