httrvsfaraday
The aim of httr is to provide a wrapper for the curl package, customised to the demands of modern web APIs.
Key features:
- Functions for the most important http verbs: GET(), HEAD(), PATCH(), PUT(), DELETE() and POST().
- Automatic connection sharing across requests to the same website (by default, curl handles are managed automatically), cookies are maintained across requests, and a up-to-date root-level SSL certificate store is used.
- Requests return a standard reponse object that captures the http status line, headers and body, along with other useful information.
- Response content is available with content() as a raw vector (as = "raw"), a character vector (as = "text"), or parsed into an R object (as = "parsed"), currently for html, xml, json, png and jpeg.
- You can convert http errors into R errors with stop_for_status().
- Config functions make it easier to modify the request in common ways: set_cookies(), add_headers(), authenticate(), use_proxy(), verbose(), timeout(), content_type(), accept(), progress().
- Support for OAuth 1.0 and 2.0 with oauth1.0_token() and oauth2.0_token(). The demo directory has eight OAuth demos: four for 1.0 (twitter, vimeo, withings and yahoo) and four for 2.0 (facebook, github, google, linkedin). OAuth credentials are automatically cached within a project.
Faraday is a Ruby gem that provides a simple and flexible interface for making HTTP requests. It allows you to create a Faraday connection object, which you can use to send requests and receive responses.
Faraday abstracts away the details of the underlying HTTP client library, so you can use it with different libraries such as Net::HTTP, HTTPClient, typhoeus and others.
Since Faraday can adapt many other HTTP clients it's very popular choice in web scraping.
Example Use
library(httr)
# GET requests:
resp <- GET("http://httpbin.org/get")
status_code(resp) # status code
headers(resp) # headers
str(content(resp)) # body
# POST requests:
# Form encoded
resp <- POST(url, body = body, encode = "form")
# Multipart encoded
resp <- POST(url, body = body, encode = "multipart")
# JSON encoded
resp <- POST(url, body = body, encode = "json")
# setting cookies:
resp <- GET("http://httpbin.org/cookies", set_cookies("MeWant" = "cookies"))
content(r)$cookies # get response cookies
# GET requests
response = Faraday.get('http://httpbingo.org')
put response.status
put response.headers
put response.body
# or use a persistent client session:
conn = Faraday.new(
url: 'http://httpbin.org/get',
params: {param: '1'},
headers: {'Content-Type' => 'application/json'}
)
# POST requests
response = conn.post('/post') do |req|
req.params['limit'] = 100
req.body = {query: 'chunky bacon'}.to_json
end