class FaradayMiddleware::Caching

Public: Caches GET responses and pulls subsequent ones from the cache.

Constants

CACHEABLE_STATUS_CODES

Internal: List of status codes that can be cached:

  • 200 - 'OK'

  • 203 - 'Non-Authoritative Information'

  • 300 - 'Multiple Choices'

  • 301 - 'Moved Permanently'

  • 302 - 'Found'

  • 404 - 'Not Found'

  • 410 - 'Gone'

Attributes

cache[R]

Public Class Methods

new(app, cache = nil, options = {}) { || ... } click to toggle source

Public: initialize the middleware.

cache - An object that responds to read, write and fetch (default: nil). options - An options Hash (default: {}):

:ignore_params - String name or Array names of query params
                 that should be ignored when forming the cache
                 key (default: []).

Yields if no cache is given. The block should return a cache object.

Calls superclass method
# File lib/faraday_middleware/response/caching.rb, line 32
def initialize(app, cache = nil, options = {})
  super(app)
  options, cache = cache, nil if cache.is_a? Hash and block_given?
  @cache = cache || yield
  @options = options
end

Public Instance Methods

cache_key(env) click to toggle source
# File lib/faraday_middleware/response/caching.rb, line 61
def cache_key(env)
  url = env[:url].dup
  if url.query && params_to_ignore.any?
    params = parse_query url.query
    params.reject! {|k,| params_to_ignore.include? k }
    url.query = params.any? ? build_query(params) : nil
  end
  url.normalize!
  url.request_uri
end
cache_on_complete(env) click to toggle source
# File lib/faraday_middleware/response/caching.rb, line 76
def cache_on_complete(env)
  key = cache_key(env)
  if cached_response = cache.read(key)
    finalize_response(cached_response, env)
  else
    response = @app.call(env)
    if CACHEABLE_STATUS_CODES.include?(response.status)
      response.on_complete { cache.write(key, response) }
    end
  end
end
call(env) click to toggle source
# File lib/faraday_middleware/response/caching.rb, line 39
def call(env)
  if :get == env[:method]
    if env[:parallel_manager]
      # callback mode
      cache_on_complete(env)
    else
      # synchronous mode
      key = cache_key(env)
      unless response = cache.read(key) and response
        response = @app.call(env)

        if CACHEABLE_STATUS_CODES.include?(response.status)
          cache.write(key, response)
        end
      end
      finalize_response(response, env)
    end
  else
    @app.call(env)
  end
end
finalize_response(response, env) click to toggle source
# File lib/faraday_middleware/response/caching.rb, line 88
def finalize_response(response, env)
  response = response.dup if response.frozen?
  env[:response] = response
  unless env[:response_headers]
    env.update response.env
    # FIXME: omg hax
    response.instance_variable_set('@env', env)
  end
  response
end
params_to_ignore() click to toggle source
# File lib/faraday_middleware/response/caching.rb, line 72
def params_to_ignore
  @params_to_ignore ||= Array(@options[:ignore_params]).map { |p| p.to_s }
end