The document discusses the use of R clients to access web APIs, emphasizing the concept of APIs and the methods for making requests (GET, POST, PUT, PATCH, DELETE) using R's httr package. It provides case studies demonstrating how to interact with APIs, including building URLs, obtaining authorization, and processing responses. Additionally, it showcases examples related to organizing Google Drive files and obtaining data from platforms like Twitter and GitHub.

1. HARNESSING THE POWER OF THE WEB
VIA R CLIENTS FOR WEB APIS
Lucy D’Agostino McGowan, PhD
Johns Hopkins Bloomberg School
of Public Health
@LucyStats

2. JSM 2018
OUTLINE
! What is an API?

3. JSM 2018
OUTLINE
! What is an API?
! How are APIs accessed from R

4. JSM 2018
OUTLINE
! What is an API?
! How are APIs accessed from R
! Case studies

5. JSM 2018
OUTLINE
! What is an API?
! How are APIs accessed from R
! Case studies

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API

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APIapplication

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APIapplication programming

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APIapplication programming interface

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RESTful
API

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HyperText Transfer Protocol
REQUEST VIA HTTP METHODS

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GET
POST
PUT
PATCH
DELETE
REQUEST VIA HTTP METHODS
HyperText Transfer Protocol

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GET
POST
PUT
PATCH
DELETE
REQUEST VIA HTTP METHODS

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GET
POST
PUT
PATCH
DELETE
REQUEST VIA HTTP METHODS

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GET
POST
PUT
PATCH
DELETE
REQUEST VIA HTTP METHODS

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GET
POST
PUT
PATCH
DELETE
REQUEST VIA HTTP METHODS

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GET
POST
PUT
PATCH
DELETE
REQUEST VIA HTTP METHODS

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HTTP Methods

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ü Choose Method

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Built a set of urls
that return data

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Built a set of urls
that return data

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Built a set of urls
that return data
https://developer.twitter.com/en/docs.html

27. JSM 2018
Built a set of urls
that return data
https://developer.twitter.com/en/docs.html
https://developers.google.com/drive/api/v3/reference/

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Built a set of urls
that return data
https://developer.twitter.com/en/docs.html
https://developers.google.com/drive/api/v3/reference/
https://developer.github.com/v3/

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Built a set of urls
that return data

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Built a set of urls
that return data,
often JSON

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JSONJavaScript

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JSONJavaScript Object

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JSONJavaScript Object Notation

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according to json.org
light weight data-interchange
format
JSON

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according to json.org
light weight data-interchange
format
easy for humans to read /
write
JSON

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according to json.org
light weight data-interchange
format
easy for humans to read /
write
easy for computers to parse /
generate
JSON

37. JSM 2018
JSON
[
{
"statuses": {
"created_at": "Thu Jul 19 21:45:08 +0000 2018",
"id": 1020062005892470000,
"id_str": "1020062005892468738",
"full_text": "Our team are looking forward to
meeting all the @AmstatNews attendees in
Vancouver next week #JSM2018 #Vancouver
#Canada https://t.co/XiOrCtuUOk",
. . .
}
}
]

38. JSM 2018
JSON
[
{
"statuses": {
"created_at": "Thu Jul 19 21:45:08 +0000 2018",
"id": 1020062005892470000,
"id_str": "1020062005892468738",
"full_text": "Our team are looking forward to
meeting all the @AmstatNews attendees in
Vancouver next week #JSM2018 #Vancouver
#Canada https://t.co/XiOrCtuUOk",
. . .
}
}
]
name

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JSON
[
{
"statuses": {
"created_at": "Thu Jul 19 21:45:08 +0000 2018",
"id": 1020062005892470000,
"id_str": "1020062005892468738",
"full_text": "Our team are looking forward to
meeting all the @AmstatNews attendees in
Vancouver next week #JSM2018 #Vancouver
#Canada https://t.co/XiOrCtuUOk",
. . .
}
}
]
name value

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JSON
HTTP Methods

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ü Choose Method
ü Build URL

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HTTP Methods
JSON

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OAuth

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OAuthOpen

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OAuthOpen Authorization

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ü Choose Method
ü Build URL
ü Get Authorization

47. JSM 2018
OUTLINE
! What is an API?
! How are APIs accessed from R
! Case studies

48. JSM 2018
httr

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q Choose Method
q Build URL
q Get Authorization
q Make Request
q Process Response

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q Choose Method
q Build URL
q Get Authorization
q Make Request
q Process Response

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REQUEST VIA HTTP METHODS
GET
POST
PUT
PATCH
DELETE
httr::GET()
httr::POST()
httr::PUT()
httr::PATCH()
httr::DELETE()

53. JSM 2018
REQUEST VIA HTTP METHODS
GET
POST
PUT
PATCH
DELETE
httr::GET()
httr::POST()
httr::PUT()
httr::PATCH()
httr::DELETE()

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ü Choose Method
q Build URL
q Get Authorization
q Make Request
q Process Response

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BUILD URL
library(httr)
url <- modify_url(
url = "https://api.github.com/",
path = "repos/tidyverse/googledrive/issues",
query = list(labels = "docs")
)
https://api.github.com/repos/tidyverse/googledrive/issues?labels=docs

56. JSM 2018
BUILD URL
library(httr)
url <- modify_url(
url = "https://api.github.com/",
path = "repos/tidyverse/googledrive/issues",
query = list(labels = "docs")
)
https://api.github.com/repos/tidyverse/googledrive/issues?labels=docs
base URL

57. JSM 2018
BUILD URL
library(httr)
url <- modify_url(
url = "https://api.github.com/",
path = "repos/tidyverse/googledrive/issues",
query = list(labels = "docs")
)
https://api.github.com/repos/tidyverse/googledrive/issues?labels=docs
base URL endpoint

58. JSM 2018
BUILD URL
https://api.github.com/repos/tidyverse/googledrive/issues?labels=docs
library(httr)
url <- modify_url(
url = "https://api.github.com/",
path = "repos/tidyverse/googledrive/issues",
query = list(labels = "docs")
)
base URL endpoint parameters

59. JSM 2018
ü Choose Method
ü Build URL
q Get Authorization
q Make Request
q Process Response

60. JSM 2018
AUTHENTICATION
1 Register an
application
https://github.com/settings/developers

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AUTHENTICATION
1 2Register an
application
Create an OAuth
application
library(httr)
app <- oauth_app(
appname = "NAME",
key = "KEY",
secret = "SECRET"
)
https://github.com/settings/developers

62. JSM 2018
AUTHENTICATION
1 2Register an
application
Create an OAuth
application
3 Generate a
token
library(httr)
app <- oauth_app(
appname = "NAME",
key = "KEY",
secret = "SECRET"
)
token <-
oauth2.0_token(
oauth_endpoints("github"),
app
)
https://github.com/settings/developers

63. JSM 2018
AUTHENTICATION
1 2Register an
application
Create an OAuth
application
3 Generate a
token
library(httr)
app <- oauth_app(
appname = "NAME",
key = "KEY",
secret = "SECRET"
)
token <-
oauth2.0_token(
oauth_endpoints("github"),
app
)
https://github.com/settings/developers

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ü Choose Method
ü Build URL
ü Get Authorization
q Make Request
q Process Response

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library(httr)
req <- GET(url, config = token)
REQUEST

67. JSM 2018
library(httr)
req <- GET(url, config = token)
req
#> Response
#> [https://api.github.com/repos/tidyverse/googledrive/issues?labels=docs]
#> Date: 2018-07-20 14:35
#> Status: 200
#> Content-Type: application/json; charset=utf-8
#> Size: 86.6 kB
#> [
#> {
#> "url": "https://api.github.com/repos/tidyverse/googledrive/issues/150",
#> "repository_url": "https://api.github.com/repos/tidyverse/googledrive",
#> ...
REQUEST

68. JSM 2018
library(httr)
req <- GET(url, config = token)
req
#> Response
#> [https://api.github.com/repos/tidyverse/googledrive/issues?label=docs]
#> Date: 2018-07-20 14:35
#> Status: 200
#> Content-Type: application/json; charset=utf-8
#> Size: 86.6 kB
#> [
#> {
#> "url": "https://api.github.com/repos/tidyverse/googledrive/issues/150",
#> "repository_url": "https://api.github.com/repos/tidyverse/googledrive",
#> ...
REQUEST

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ü Choose Method
ü Build URL
ü Get Authorization
ü Make Request
q Process Response

70. JSM 2018
library(httr)
req <- GET(url, config = token)
res <- content(req)
PROCESS

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library(httr)
req <- GET(url, config = token)
res <- content(req)
res
#> [[1]]
#> [[1]]$url
#> [1] "https://api.github.com/repos/tidyverse/googledrive/issues/150"
#>
#> [[1]]$repository_url
#> [1] "https://api.github.com/repos/tidyverse/googledrive"
PROCESS

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library(httr)
req <- GET(url, config = token)
res <- content(req)
res
#> [[1]]
#> [[1]]$url
#> [1] "https://api.github.com/repos/tidyverse/googledrive/issues/150"
#>
#> [[1]]$repository_url
#> [1] "https://api.github.com/repos/tidyverse/googledrive"
PROCESS

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library(httr)
req <- GET(url, config = token)
res <- content(req)
purrr::map_chr(res, "url")
PROCESS

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library(httr)
req <- GET(url, config = token)
res <- content(req)
purrr::map_chr(res, "url")
#> [1] "https://api.github.com/repos/tidyverse/googledrive/issues/150"
#> [2] "https://api.github.com/repos/tidyverse/googledrive/issues/123"
#> [3] "https://api.github.com/repos/tidyverse/googledrive/issues/79"
PROCESS

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ü Choose Method
ü Build URL
ü Get Authorization
ü Make Request
ü Process Response

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gh
rtweet
googledrive
googlesheets
yelpr
meetupr
imugR
aws.*

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library(googledrive)
drive_ls()

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library(googledrive)
drive_ls()
#> Waiting for authentication in browser...
#> Press Esc/Ctrl + C to abort

79. JSM 2018

80. JSM 2018
library(googledrive)
drive_ls()
#> Waiting for authentication in browser...
#> Press Esc/Ctrl + C to abort
#> Authentication complete.
#> Items so far:
#> 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1670
#> # A tibble: 1,670 x 3
#> name id drive_resource
#> * <chr> <chr> <list>
#> 1 data.zip 1ET81D_Uku6Tm_Z4U04jB4qTNrC… <list [37]>
#> 2 science_manuscript 10X07LsQI5GL_Tdrq3-3PtgcDtW… <list [31]>
#> 3 talks 12bBwImIu4Yzg5UaqcvxIZ0rbyG… <list [31]>
#> 4 presentations 1-PItelqpv0Sb_LdiEDqb8O3D_R… <list [32]>
#> 5 science_supplementary_materials 1JNogHk0Zn-H5je6a-DBh0muwBW… <list [31]>
#> 6 iris-collaboration-analysis-plan 10DrdHfxyPFTuACKO5YqcpFrcPM… <list [32]>
#> 7 2018-07-16_meeting-minutes 1oUAPeFSvVfo5BBoeCip-2kuOup… <list [32]>
#> 8 p-hack-athon.Rda 1cwgv9GkrgcVEImxcKSni-Tdf-B… <list [32]>
#> 9 rladies-pres 1-cSy2GqNumuD2YpeIOG_Tv2aQ-… <list [33]>
#> 10 Women in Statistics 1ZRK0Bonakg_qkg5McU7Lr9fpDx… <list [30]>
#> # ... with 1,660 more rows

81. JSM 2018
OUTLINE
! What is an API?
! How are APIs accessed from R
! Case studies

82. JSM 2018
UPLOAD MY SLIDES TO DRIVE
library(googledrive)
drive_upload("2018-07_jsm/slides.pptx",
path = "postdoc/talks/",
name = "2018-07_jsm_slides",
type = "presentation")

83. JSM 2018
ORGANIZE MY DRIVE FROM THE COMFORT OF MY
CONSOLE
library(googledrive)
leek_files <- drive_find(q = "'jtleek@gmail.com' in writers")
postdoc_folder <- drive_mkdir("postdoc")
purrr::walk(leek_files$id,
~drive_mv(as_id(.x), path = postdoc_folder)
)

84. JSM 2018
ORGANIZE MY DRIVE FROM THE COMFORT OF MY
CONSOLE
library(googledrive)
leek_files <- drive_find(q = "'jtleek@gmail.com' in writers")
postdoc_folder <- drive_mkdir("postdoc")
purrr::walk(leek_files$id,
~drive_mv(as_id(.x), path = postdoc_folder)
)

85. JSM 2018
ORGANIZE MY DRIVE FROM THE COMFORT OF MY
CONSOLE
library(googledrive)
leek_files <- drive_find(q = "'jtleek@gmail.com' in writers")
postdoc_folder <- drive_mkdir("postdoc")
purrr::walk(leek_files$id,
~drive_mv(as_id(.x), path = postdoc_folder)
)

86. JSM 2018
PULLING MOST FREQUENT SLACK EMOJI
http://livefreeordichotomize.com/2017/07/17/ropensci-slack-emojis/

87. JSM 2018
NAVIGATING TWITTER RESPONSES
http://livefreeordichotomize.com/2017/07/24/twitter-trees/

88. JSM 2018
WE R LADIES
http://livefreeordichotomize.com/2017/07/18/the-making-of-we-r-ladies/

89. @LUCYSTATS
bit.ly/lucystats-jsm2018
LUCYDAGOSTINO@GMAIL.COM
Thank you!
HARNESSING THE POWER OF THE
WEB VIA R CLIENTS FOR WEB APIS
Lucy D’Agostino
McGowan, PhD
Johns Hopkins Bloomberg
School of Public Health