class FaradayMiddleware::FollowRedirects
Public: Follow HTTP 301, 302, 303, and 307 redirects.
For HTTP 301, 302, and 303, the original GET, POST, PUT, DELETE, or PATCH request gets converted into a GET. With `:standards_compliant => true`, however, the HTTP method after 301/302 remains unchanged. This allows you to opt into HTTP/1.1 compliance and act unlike the major web browsers.
This middleware currently only works with synchronous requests; i.e. it doesn't support parallelism.
If you wish to persist cookies across redirects, you could use the faraday-cookie_jar gem:
Faraday.new(:url => url) do |faraday| faraday.use FaradayMiddleware::FollowRedirects faraday.use :cookie_jar faraday.adapter Faraday.default_adapter end
Constants
- ALLOWED_METHODS
HTTP methods for which 30x redirects can be followed
- ENV_TO_CLEAR
Keys in env hash which will get cleared between requests
- FOLLOW_LIMIT
Default value for max redirects followed
- REDIRECT_CODES
HTTP redirect status codes that this middleware implements
- URI_UNSAFE
Regex that matches characters that need to be escaped in URLs, sans the “%” character which we assume already represents an escaped sequence.
Public Class Methods
Public: Initialize the middleware.
options - An options Hash (default: {}):
:limit - A Numeric redirect limit (default: 3) :standards_compliant - A Boolean indicating whether to respect the HTTP spec when following 301/302 (default: false)
# File lib/faraday_middleware/response/follow_redirects.rb, line 55 def initialize(app, options = {}) super(app) @options = options @convert_to_get = Set.new [303] @convert_to_get << 301 << 302 unless standards_compliant? end
Public Instance Methods
# File lib/faraday_middleware/response/follow_redirects.rb, line 63 def call(env) perform_with_redirection(env, follow_limit) end
Private Instance Methods
# File lib/faraday_middleware/response/follow_redirects.rb, line 69 def convert_to_get?(response) ![:head, :options].include?(response.env[:method]) && @convert_to_get.include?(response.status) end
# File lib/faraday_middleware/response/follow_redirects.rb, line 108 def follow_limit @options.fetch(:limit, FOLLOW_LIMIT) end
# File lib/faraday_middleware/response/follow_redirects.rb, line 103 def follow_redirect?(env, response) ALLOWED_METHODS.include? env[:method] and REDIRECT_CODES.include? response.status end
# File lib/faraday_middleware/response/follow_redirects.rb, line 74 def perform_with_redirection(env, follows) request_body = env[:body] response = @app.call(env) response.on_complete do |response_env| if follow_redirect?(response_env, response) raise RedirectLimitReached, response if follows.zero? new_request_env = update_env(response_env, request_body, response) response = perform_with_redirection(new_request_env, follows - 1) end end response end
Internal: escapes unsafe characters from an URL which might be a path component only or a fully qualified URI so that it can be joined onto an URI:HTTP using the `+` operator. Doesn't escape “%” characters so to not risk double-escaping.
# File lib/faraday_middleware/response/follow_redirects.rb, line 120 def safe_escape(uri) uri.to_s.gsub(URI_UNSAFE) { |match| '%' + match.unpack('H2' * match.bytesize).join('%').upcase } end
# File lib/faraday_middleware/response/follow_redirects.rb, line 112 def standards_compliant? @options.fetch(:standards_compliant, false) end
# File lib/faraday_middleware/response/follow_redirects.rb, line 88 def update_env(env, request_body, response) env[:url] += safe_escape(response['location']) if convert_to_get?(response) env[:method] = :get env[:body] = nil else env[:body] = request_body end ENV_TO_CLEAR.each {|key| env.delete key } env end