aboutsummaryrefslogtreecommitdiffstats
path: root/actionpack/lib/action_dispatch/middleware/stack.rb
blob: 466eb8b3f1cad3fbebf7d8351075bab9662329ee (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
require "active_support/inflector/methods"
require "active_support/dependencies"

module ActionDispatch
  class MiddlewareStack
    class Middleware
      attr_reader :args, :block, :klass

      def initialize(klass, args, block)
        @klass = klass
        @args  = args
        @block = block
      end

      def name; klass.name; end

      def ==(middleware)
        case middleware
        when Middleware
          klass == middleware.klass
        when Class
          klass == middleware
        end
      end

      def inspect
        if klass.is_a?(Class)
          klass.to_s
        else
          klass.class.to_s
        end
      end

      def build(app)
        klass.new(app, *args, &block)
      end
    end

    include Enumerable

    attr_accessor :middlewares

    def initialize(*args)
      @middlewares = []
      yield(self) if block_given?
    end

    def each
      @middlewares.each { |x| yield x }
    end

    def size
      middlewares.size
    end

    def last
      middlewares.last
    end

    def [](i)
      middlewares[i]
    end

    def unshift(klass, *args, &block)
      middlewares.unshift(build_middleware(klass, args, block))
    end

    def initialize_copy(other)
      self.middlewares = other.middlewares.dup
    end

    def insert(index, klass, *args, &block)
      index = assert_index(index, :before)
      middlewares.insert(index, build_middleware(klass, args, block))
    end

    alias_method :insert_before, :insert

    def insert_after(index, *args, &block)
      index = assert_index(index, :after)
      insert(index + 1, *args, &block)
    end

    def swap(target, *args, &block)
      index = assert_index(target, :before)
      insert(index, *args, &block)
      middlewares.delete_at(index + 1)
    end

    def delete(target)
      target = get_class target
      middlewares.delete_if { |m| m.klass == target }
    end

    def use(klass, *args, &block)
      middlewares.push(build_middleware(klass, args, block))
    end

    def build(app = Proc.new)
      middlewares.freeze.reverse.inject(app) { |a, e| e.build(a) }
    end

    private

      def assert_index(index, where)
        index = get_class index
        i = index.is_a?(Integer) ? index : middlewares.index { |m| m.klass == index }
        raise "No such middleware to insert #{where}: #{index.inspect}" unless i
        i
      end

      def get_class(klass)
        if klass.is_a?(String) || klass.is_a?(Symbol)
          classcache = ActiveSupport::Dependencies::Reference
          converted_klass = classcache[klass.to_s]
          ActiveSupport::Deprecation.warn <<-eowarn
Passing strings or symbols to the middleware builder is deprecated, please change
them to actual class references.  For example:

  "#{klass}" => #{converted_klass}

          eowarn
          converted_klass
        else
          klass
        end
      end

      def build_middleware(klass, args, block)
        Middleware.new(get_class(klass), args, block)
      end
  end
end