Class: Rack::Cors

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/cors.rb,
lib/rack/cors/version.rb

Defined Under Namespace

Classes: Resource, Resources, Result

Constant Summary collapse

HTTP_ORIGIN =
'HTTP_ORIGIN'.freeze
HTTP_X_ORIGIN =
'HTTP_X_ORIGIN'.freeze
HTTP_ACCESS_CONTROL_REQUEST_METHOD =
'HTTP_ACCESS_CONTROL_REQUEST_METHOD'.freeze
HTTP_ACCESS_CONTROL_REQUEST_HEADERS =
'HTTP_ACCESS_CONTROL_REQUEST_HEADERS'.freeze
PATH_INFO =
'PATH_INFO'.freeze
REQUEST_METHOD =
'REQUEST_METHOD'.freeze
RACK_LOGGER =
'rack.logger'.freeze
RACK_CORS =
ENV_KEY     = 'rack.cors'.freeze
OPTIONS =
'OPTIONS'.freeze
VARY =
'Vary'.freeze
DEFAULT_VARY_HEADERS =
['Origin'].freeze
CORS_SIMPLE_HEADERS =

All CORS routes need to accept CORS simple headers at all times https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Access-Control-Allow-Headers

['accept', 'accept-language', 'content-language', 'content-type'].freeze
VERSION =
"1.1.1"

Instance Method Summary collapse

Constructor Details

#initialize(app, opts = {}, &block) ⇒ Cors

Returns a new instance of Cors.


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# File 'lib/rack/cors.rb', line 28

def initialize(app, opts={}, &block)
  @app = app
  @debug_mode = !!opts[:debug]
  @logger = @logger_proc = nil

  if logger = opts[:logger]
    if logger.respond_to? :call
      @logger_proc = opts[:logger]
    else
      @logger = logger
    end
  end

  if block_given?
    if block.arity == 1
      block.call(self)
    else
      instance_eval(&block)
    end
  end
end

Instance Method Details

#allow(&block) ⇒ Object


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# File 'lib/rack/cors.rb', line 54

def allow(&block)
  all_resources << (resources = Resources.new)

  if block.arity == 1
    block.call(resources)
  else
    resources.instance_eval(&block)
  end
end

#call(env) ⇒ Object


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# File 'lib/rack/cors.rb', line 64

def call(env)
  env[HTTP_ORIGIN] ||= env[HTTP_X_ORIGIN] if env[HTTP_X_ORIGIN]

  path = evaluate_path(env)

  add_headers = nil
  if env[HTTP_ORIGIN]
    debug(env) do
      [ 'Incoming Headers:',
        "  Origin: #{env[HTTP_ORIGIN]}",
        "  Path-Info: #{path}",
        "  Access-Control-Request-Method: #{env[HTTP_ACCESS_CONTROL_REQUEST_METHOD]}",
        "  Access-Control-Request-Headers: #{env[HTTP_ACCESS_CONTROL_REQUEST_HEADERS]}"
        ].join("\n")
    end

    if env[REQUEST_METHOD] == OPTIONS && env[HTTP_ACCESS_CONTROL_REQUEST_METHOD]
      return [400, {}, []] unless Rack::Utils.valid_path?(path)
      headers = process_preflight(env, path)
      debug(env) do
        "Preflight Headers:\n" +
            headers.collect{|kv| "  #{kv.join(': ')}"}.join("\n")
      end
      return [200, headers, []]
    else
      add_headers = process_cors(env, path)
    end
  else
    Result.miss(env, Result::MISS_NO_ORIGIN)
  end

  # This call must be done BEFORE calling the app because for some reason
  # env[PATH_INFO] gets changed after that and it won't match. (At least
  # in rails 4.1.6)
  vary_resource = resource_for_path(path)

  status, headers, body = @app.call env

  if add_headers
    headers = add_headers.merge(headers)
    debug(env) do
      add_headers.each_pair do |key, value|
        if headers.has_key?(key)
          headers["X-Rack-CORS-Original-#{key}"] = value
        end
      end
    end
  end

  # Vary header should ALWAYS mention Origin if there's ANY chance for the
  # response to be different depending on the Origin header value.
  # Better explained here: http://www.fastly.com/blog/best-practices-for-using-the-vary-header/
  if vary_resource
    vary = headers[VARY]
    cors_vary_headers = if vary_resource.vary_headers && vary_resource.vary_headers.any?
      vary_resource.vary_headers
    else
      DEFAULT_VARY_HEADERS
    end
    headers[VARY] = ((vary ? ([vary].flatten.map { |v| v.split(/,\s*/) }.flatten) : []) + cors_vary_headers).uniq.join(', ')
  end

  if debug? && result = env[RACK_CORS]
    result.append_header(headers)
  end

  [status, headers, body]
end

#debug?Boolean

Returns:

  • (Boolean)

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# File 'lib/rack/cors.rb', line 50

def debug?
  @debug_mode
end