Class: Rack::Cascade

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/cascade.rb

Overview

Rack::Cascade tries a request on several apps, and returns the first response that is not 404 or 405 (or in a list of configurable status codes).

Constant Summary collapse

NotFound =
[404, {CONTENT_TYPE => "text/plain"}, []]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(apps, catch = [404, 405]) ⇒ Cascade

Returns a new instance of Cascade


11
12
13
14
15
16
17
# File 'lib/rack/cascade.rb', line 11

def initialize(apps, catch=[404, 405])
  @apps = []; @has_app = {}
  apps.each { |app| add app }

  @catch = {}
  [*catch].each { |status| @catch[status] = true }
end

Instance Attribute Details

#appsObject (readonly)

Returns the value of attribute apps


9
10
11
# File 'lib/rack/cascade.rb', line 9

def apps
  @apps
end

Instance Method Details

#add(app) ⇒ Object Also known as: <<


41
42
43
44
# File 'lib/rack/cascade.rb', line 41

def add(app)
  @has_app[app] = true
  @apps << app
end

#call(env) ⇒ Object


19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
# File 'lib/rack/cascade.rb', line 19

def call(env)
  result = NotFound

  last_body = nil

  @apps.each do |app|
    # The SPEC says that the body must be closed after it has been iterated
    # by the server, or if it is replaced by a middleware action. Cascade
    # replaces the body each time a cascade happens. It is assumed that nil
    # does not respond to close, otherwise the previous application body
    # will be closed. The final application body will not be closed, as it
    # will be passed to the server as a result.
    last_body.close if last_body.respond_to? :close

    result = app.call(env)
    last_body = result[2]
    break unless @catch.include?(result[0].to_i)
  end

  result
end

#include?(app) ⇒ Boolean

Returns:

  • (Boolean)

46
47
48
# File 'lib/rack/cascade.rb', line 46

def include?(app)
  @has_app.include? app
end