Class: Aquarium::Aspects::JoinPoint::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/aquarium/aspects/join_point.rb

Overview

JoinPoint::Context

Encapsulates current runtime context information for a join point, such as the values of method parameters, a raised exception (for :after or after_raising advice), etc. Context objects are partly value objects. TODO Separate out the read-only part from the variable part. This might require an API change!

Constant Summary collapse

NIL_OBJECT = 
Aquarium::Utils::NilObject.new

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Context

Returns a new instance of Context.



32
33
34
 
# File 'lib/aquarium/aspects/join_point.rb', line 32

def initialize options = {}
  update options
end

Instance Attribute Details

#advice_kind ⇒ Object

Returns the value of attribute advice_kind.



25
26
27
 
# File 'lib/aquarium/aspects/join_point.rb', line 25

def advice_kind
  @advice_kind
end

#advised_object ⇒ Object Also known as: target_object

Returns the value of attribute advised_object.



25
26
27
 
# File 'lib/aquarium/aspects/join_point.rb', line 25

def advised_object
  @advised_object
end

#block_for_method ⇒ Object

Returns the value of attribute block_for_method.



26
27
28
 
# File 'lib/aquarium/aspects/join_point.rb', line 26

def block_for_method
  @block_for_method
end

#current_advice_node ⇒ Object

Returns the value of attribute current_advice_node.



25
26
27
 
# File 'lib/aquarium/aspects/join_point.rb', line 25

def current_advice_node
  @current_advice_node
end

#parameters ⇒ Object

Returns the value of attribute parameters.



25
26
27
 
# File 'lib/aquarium/aspects/join_point.rb', line 25

def parameters
  @parameters
end

#proceed_proc ⇒ Object

Returns the value of attribute proceed_proc.



25
26
27
 
# File 'lib/aquarium/aspects/join_point.rb', line 25

def proceed_proc
  @proceed_proc
end

#raised_exception ⇒ Object

Returns the value of attribute raised_exception.



26
27
28
 
# File 'lib/aquarium/aspects/join_point.rb', line 26

def raised_exception
  @raised_exception
end

#returned_value ⇒ Object

Returns the value of attribute returned_value.



26
27
28
 
# File 'lib/aquarium/aspects/join_point.rb', line 26

def returned_value
  @returned_value
end

Instance Method Details

#<=>(other) ⇒ Object 



67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
 
# File 'lib/aquarium/aspects/join_point.rb', line 67

def <=> other
  return 0 if object_id == other.object_id 
  return 1 if other.nil?
  result = self.class <=> other.class 
  return result unless result == 0
  result = Advice.compare_advice_kinds self.advice_kind, other.advice_kind
  return result unless result == 0
  result = (self.advised_object.object_id.nil? and other.advised_object.object_id.nil?) ? 0 : self.advised_object.object_id <=> other.advised_object.object_id 
  return result unless result == 0
  result = (self.parameters.nil? and other.parameters.nil?) ? 0 : self.parameters <=> other.parameters 
  return result unless result == 0
  result = (self.returned_value.nil? and other.returned_value.nil?) ? 0 : self.returned_value <=> other.returned_value 
  return result unless result == 0
  (self.raised_exception.nil? and other.raised_exception.nil?) ? 0 : self.raised_exception <=> other.raised_exception
end

#eql?(other) ⇒ Boolean Also known as: ==, ===

Returns:

  • (Boolean) 


83
84
85
 
# File 'lib/aquarium/aspects/join_point.rb', line 83

def eql? other
  (self <=> other) == 0
end

#inspect ⇒ Object 



61
62
63
64
65
 
# File 'lib/aquarium/aspects/join_point.rb', line 61

def inspect
  "JoinPoint::Context: {advice_kind = #{advice_kind}, advised_object = #{advised_object}, parameters = #{parameters}, " +
  "proceed_proc = #{proceed_proc}, current_advice_node = #{current_advice_node.inspect}, returned_value = #{returned_value}, " +
  "raised_exception = #{raised_exception}, block_for_method = #{block_for_method}}"
end

#invoke_original_join_point(enclosing_join_point, *args, &block) ⇒ Object

Raises:



52
53
54
55
56
57
 
# File 'lib/aquarium/aspects/join_point.rb', line 52

def invoke_original_join_point enclosing_join_point, *args, &block
  raise ContextNotCorrectlyDefined.new("It looks like you tried to call \"JoinPoint#invoke_original_join_point\" (or \"JoinPoint::Context#invoke_original_join_point\") using a join point without a completely formed context object. (Specific error: The original join point cannot be invoked because no \"@current_advice_node\" attribute was set on the corresponding JoinPoint::Context object.)") if @current_advice_node.nil?
  enclosing_join_point.context.parameters = args unless args.nil? or args.empty? 
  enclosing_join_point.context.block_for_method = block if block 
  current_advice_node.invoke_original_join_point enclosing_join_point
end

#proceed(enclosing_join_point, *args, &block) ⇒ Object

Raises:



45
46
47
48
49
50
 
# File 'lib/aquarium/aspects/join_point.rb', line 45

def proceed enclosing_join_point, *args, &block
  raise ProceedMethodNotAvailable.new("It looks like you tried to call \"JoinPoint#proceed\" (or \"JoinPoint::Context#proceed\") from within advice that isn't \"around\" advice. Only around advice can call proceed. (Specific error: JoinPoint#proceed cannot be invoked because no \"@proceed_proc\" attribute was set on the corresponding JoinPoint::Context object.)") if @proceed_proc.nil?
  enclosing_join_point.context.parameters = args unless args.nil? or args.empty? 
  enclosing_join_point.context.block_for_method = block if block 
  proceed_proc.call enclosing_join_point
end

#to_s ⇒ Object 



59
 
# File 'lib/aquarium/aspects/join_point.rb', line 59

alias :to_s :inspect

#update(options) ⇒ Object 



36
37
38
39
40
41
42
43
 
# File 'lib/aquarium/aspects/join_point.rb', line 36

def update options
  options.each do |key, value|
    instance_variable_set "@#{key}", value
  end
  @advice_kind    ||= Advice::UNKNOWN_ADVICE_KIND
  @advised_object ||= NIL_OBJECT
  @parameters     ||= []
end