Module: Interloper::ClassMethods

Defined in:
lib/interloper.rb

Instance Method Summary collapse

Instance Method Details

#after(*method_names, &callback) ⇒ Object 



113
114
115
116
 
# File 'lib/interloper.rb', line 113

def after(*method_names, &callback)
  interloper_module.define_interloper_methods(*method_names, interloper_const_name)
  interloper_module.add_callbacks(:after, *method_names, &callback)
end

#ancestor_interloper_module ⇒ Module

Returns The nearest ancstors tha is an interloper module.

Returns:

  • (Module) —

    The nearest ancstors tha is an interloper module.



142
143
144
145
146
 
# File 'lib/interloper.rb', line 142

def ancestor_interloper_module
  ancestors.detect do |ancestor|
     ancestor.respond_to?(:interloper_module) && (ancestor != self)
  end.interloper_module
end

#before(*method_names, &callback) ⇒ Object 



108
109
110
111
 
# File 'lib/interloper.rb', line 108

def before(*method_names, &callback)
  interloper_module.define_interloper_methods(*method_names, interloper_const_name)
  interloper_module.add_callbacks(:before, *method_names, &callback)
end

#generate_interloper_module ⇒ Object 



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
 
# File 'lib/interloper.rb', line 36

def generate_interloper_module
  Module.new do
    class << self
      # @return [Array] The list of available hooks.
      def hooks
        [:before, :after]
      end

      # @return [Hash] The default hash for tracking callbacks to methods.
      def default_callbacks
        {}.tap do |callbacks|
          hooks.each do |hook|
            callbacks[hook] = {}
          end
        end
      end

      # @param [Symbol] hook Optional name of a hook. See .hook method in
      #   this module.
      # @param [Symbol] method_name Optional name of a method.
      # @return [Hash, Array] A hash or array of callbacks. If the 'hook'
      #   param is provided, it will return a hash of callbacks keyed by
      #   method name. If both 'hook' and 'method_name' are provided, will
      #   return an array of callbacks for the given hook and method.
      def callbacks(hook=nil, method_name=nil)
        @callbacks ||= default_callbacks
        if hook && method_name
          # Returns callback stack for a given method and hook. If there
          # aren't callbacks in the stack, return something enumberable to
          # be loop-friendly.
          @callbacks.fetch(hook).fetch(method_name, [])
        elsif hook
          # Return all callbacks for a given hook, e.g. :before.
          @callbacks.fetch(hook)
        else
          @callbacks
        end
      end

      def run_callbacks(hook, method_name, object_context, *orig_args, &orig_block)
        callbacks(hook, method_name).each do |callback|
          object_context.instance_exec *orig_args, &callback
        end
      end

      def add_callbacks(hook, *method_names, &callback)
        method_names.each do |method_name|
          callbacks[hook][method_name] ||= []
          callbacks[hook][method_name] << callback
        end
      end

      def define_interloper_methods(*method_names, interloper_module_name)
        method_names.each do |method_name|
          unless instance_methods.include? method_name
            module_eval do
              eval "                def \#{method_name}(*args, &block)\n                  self.class.const_get(:\#{interloper_module_name}).run_callbacks(:before, :\#{method_name}, self, *args, &block)\n                  return_val = super(*args, &block)\n                  self.class.const_get(:\#{interloper_module_name}).run_callbacks(:after, :\#{method_name}, self, *args, &block)\n                  return_val\n                end\n              CODE\n            end\n          end\n        end\n      end\n    end\n  end\nend\n"

#inherit_callbacks_after(*method_names) ⇒ Object 



129
130
131
132
133
 
# File 'lib/interloper.rb', line 129

def inherit_callbacks_after(*method_names)
  inherited_callbacks(:after, *method_names).each do |callback|
    after(*method_names, &callback)
  end
end

#inherit_callbacks_before(*method_names) ⇒ Object 



123
124
125
126
127
 
# File 'lib/interloper.rb', line 123

def inherit_callbacks_before(*method_names)
  inherited_callbacks(:before, *method_names).each do |callback|
    before(*method_names, &callback)
  end
end

#inherit_callbacks_for(*method_names) ⇒ Object 



118
119
120
121
 
# File 'lib/interloper.rb', line 118

def inherit_callbacks_for(*method_names)
  inherit_callbacks_before(*method_names)
  inherit_callbacks_after(*method_names)
end

#inherited_callbacks(hook, *method_names) ⇒ Object 



135
136
137
138
139
 
# File 'lib/interloper.rb', line 135

def inherited_callbacks(hook, *method_names)
  method_names.map do |method_name|
    ancestor_interloper_module.callbacks[hook][method_name]
  end.flatten
end

#interloper_const_name ⇒ Object 



15
16
17
18
19
20
21
 
# File 'lib/interloper.rb', line 15

def interloper_const_name
  if self.name
    "Interloper"
  else
    "AnonymousInterloper#{self.object_id}"
  end.to_sym
end

#interloper_module ⇒ Object

Generates an Interloper module that is namespaced under the including class, if one does not already exist. Then prepends the Interloper module to the including class.

Returns:

  • Module the Interloper module that was prepended to the including class.



28
29
30
31
32
33
34
 
# File 'lib/interloper.rb', line 28

def interloper_module
  unless self.constants.include? interloper_const_name
    const_set(interloper_const_name, generate_interloper_module)
    prepend const_get(interloper_const_name)
  end
  const_get(interloper_const_name)
end