aboutsummaryrefslogtreecommitdiffstats
path: root/actionpack/lib/abstract_controller/base.rb
blob: c384fd0978923edcad63806921ade803d222c418 (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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
require 'active_support/configurable'
require 'active_support/descendants_tracker'
require 'active_support/core_ext/module/anonymous'

module AbstractController
  class Error < StandardError; end
  class ActionNotFound < StandardError; end

  # <tt>AbstractController::Base</tt> is a low-level API. Nobody should be
  # using it directly, and subclasses (like ActionController::Base) are
  # expected to provide their own +render+ method, since rendering means
  # different things depending on the context.  
  class Base
    attr_internal :response_body
    attr_internal :action_name
    attr_internal :formats

    include ActiveSupport::Configurable
    extend ActiveSupport::DescendantsTracker

    class << self
      attr_reader :abstract
      alias_method :abstract?, :abstract

      # Define a controller as abstract. See internal_methods for more
      # details.
      def abstract!
        @abstract = true
      end

      # A list of all internal methods for a controller. This finds the first
      # abstract superclass of a controller, and gets a list of all public
      # instance methods on that abstract class. Public instance methods of
      # a controller would normally be considered action methods, so methods
      # declared on abstract classes are being removed.
      # (ActionController::Metal and ActionController::Base are defined as abstract)
      def internal_methods
        controller = self
        controller = controller.superclass until controller.abstract?
        controller.public_instance_methods(true)
      end

      # The list of hidden actions to an empty array. Defaults to an
      # empty array. This can be modified by other modules or subclasses
      # to specify particular actions as hidden.
      #
      # ==== Returns
      # * <tt>array</tt> - An array of method names that should not be considered actions.
      def hidden_actions
        []
      end

      # A list of method names that should be considered actions. This
      # includes all public instance methods on a controller, less
      # any internal methods (see #internal_methods), adding back in
      # any methods that are internal, but still exist on the class
      # itself. Finally, #hidden_actions are removed.
      #
      # ==== Returns
      # * <tt>array</tt> - A list of all methods that should be considered actions.
      def action_methods
        @action_methods ||= begin
          # All public instance methods of this class, including ancestors
          methods = (public_instance_methods(true) -
            # Except for public instance methods of Base and its ancestors
            internal_methods +
            # Be sure to include shadowed public instance methods of this class
            public_instance_methods(false)).uniq.map { |x| x.to_s } -
            # And always exclude explicitly hidden actions
            hidden_actions.to_a

          # Clear out AS callback method pollution
          methods.reject { |method| method =~ /_one_time_conditions/ }
        end
      end

      # action_methods are cached and there is sometimes need to refresh
      # them. clear_action_methods! allows you to do that, so next time
      # you run action_methods, they will be recalculated
      def clear_action_methods!
        @action_methods = nil
      end

      # Returns the full controller name, underscored, without the ending Controller.
      # For instance, MyApp::MyPostsController would return "my_app/my_posts" for
      # controller_name.
      #
      # ==== Returns
      # * <tt>string</tt>
      def controller_path
        @controller_path ||= name.sub(/Controller$/, '').underscore unless anonymous?
      end

      def method_added(name)
        super
        clear_action_methods!
      end
    end

    abstract!

    # Calls the action going through the entire action dispatch stack.
    #
    # The actual method that is called is determined by calling
    # #method_for_action. If no method can handle the action, then an
    # ActionNotFound error is raised.
    #
    # ==== Returns
    # * <tt>self</tt>
    def process(action, *args)
      @_action_name = action_name = action.to_s

      unless action_name = method_for_action(action_name)
        raise ActionNotFound, "The action '#{action}' could not be found for #{self.class.name}"
      end

      @_response_body = nil

      process_action(action_name, *args)
    end

    # Delegates to the class' #controller_path
    def controller_path
      self.class.controller_path
    end

    def action_methods
      self.class.action_methods
    end

    private

      # Returns true if the name can be considered an action. This can
      # be overridden in subclasses to modify the semantics of what
      # can be considered an action.
      #
      # ==== Parameters
      # * <tt>name</tt> - The name of an action to be tested
      #
      # ==== Returns
      # * <tt>TrueClass</tt>, <tt>FalseClass</tt>
      def action_method?(name)
        self.class.action_methods.include?(name)
      end

      # Call the action. Override this in a subclass to modify the
      # behavior around processing an action. This, and not #process,
      # is the intended way to override action dispatching.
      def process_action(method_name, *args)
        send_action(method_name, *args)
      end

      # Actually call the method associated with the action. Override
      # this method if you wish to change how action methods are called,
      # not to add additional behavior around it. For example, you would
      # override #send_action if you want to inject arguments into the
      # method.
      alias send_action send

      # If the action name was not found, but a method called "action_missing"
      # was found, #method_for_action will return "_handle_action_missing".
      # This method calls #action_missing with the current action name.
      def _handle_action_missing
        action_missing(@_action_name)
      end

      # Takes an action name and returns the name of the method that will
      # handle the action. In normal cases, this method returns the same
      # name as it receives. By default, if #method_for_action receives
      # a name that is not an action, it will look for an #action_missing
      # method and return "_handle_action_missing" if one is found.
      #
      # Subclasses may override this method to add additional conditions
      # that should be considered an action. For instance, an HTTP controller
      # with a template matching the action name is considered to exist.
      #
      # If you override this method to handle additional cases, you may
      # also provide a method (like _handle_method_missing) to handle
      # the case.
      #
      # If none of these conditions are true, and method_for_action
      # returns nil, an ActionNotFound exception will be raised.
      #
      # ==== Parameters
      # * <tt>action_name</tt> - An action name to find a method name for
      #
      # ==== Returns
      # * <tt>string</tt> - The name of the method that handles the action
      # * <tt>nil</tt>    - No method name could be found. Raise ActionNotFound.
      def method_for_action(action_name)
        if action_method?(action_name) then action_name
        elsif respond_to?(:action_missing, true) then "_handle_action_missing"
        end
      end
  end
end