Module: Aspect4r::Helper

Defined in:
lib/aspect4r/helper.rb

Constant Summary collapse

WRAP_METHOD_TEMPLATE =

method advice

ERB.new <<-CODE, nil, '<>'
<% if inner_most %>
  wrapped_method = a4r_data[:<%= method %>].wrapped_method
<% else %>
  wrapped_method = instance_method(:<%= method %>)
<% end %>

  define_method :<%= method %> do |*args|
<% if advice.options[:method_name_arg] %>
    result = <%= advice.with_method %> '<%= method %>', wrapped_method, *args
<% else %>
    result = <%= advice.with_method %> wrapped_method, *args
<% end %>
    
    result
  end
CODE
METHOD_TEMPLATE =

method before_advices after_advices

ERB.new <<-CODE, nil, '<>'
<% if inner_most %>
  wrapped_method = a4r_data[:<%= method %>].wrapped_method
<% else %>
  wrapped_method = instance_method(:<%= method %>)
<% end %>

  define_method :<%= method %> do |*args|
    result = nil

    # Before advices
<% before_advices.each do |definition| %>
<% if definition.options[:method_name_arg] %>
    result = <%= definition.with_method %> '<%= method %>', *args
<% else %>
    result = <%= definition.with_method %> *args
<% end %>

    return result.value if result.is_a? ReturnThis
<% if definition.options[:skip_if_false] %>
    return unless result
<% end %>
<% end %>

    # Call wrapped method
    result = wrapped_method.bind(self).call *args

    # After advices
<% after_advices.each do |definition| %>
<% if definition.options[:method_name_arg] and definition.options[:result_arg] %>
    result = <%= definition.with_method %> '<%= method %>', result, *args
<% elsif definition.options[:method_name_arg] %>
    <%= definition.with_method %> '<%= method %>', *args
<% elsif definition.options[:result_arg] %>
    result = <%= definition.with_method %> result, *args
<% else %>
    <%= definition.with_method %> *args
<% end %>
<% end %>
    
    result
  end
CODE

Class Method Summary collapse

Class Method Details

.create_method(klass, method) ⇒ Object

method - target method



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# File 'lib/aspect4r/helper.rb', line 66

def self.create_method klass, method
  @creating_method = true
  
  aspect = klass.a4r_data[method.to_sym]
  
  return if aspect.nil? or aspect.empty?
  
  grouped_advices = []
  group           = nil
  inner_most      = true

  aspect.each do |advice|
    if ((group and group != advice.group) or advice.around?) and not grouped_advices.empty?
      # wrap up advices before current advice
      create_method_for_before_after_advices klass, method, grouped_advices, inner_most
      
      grouped_advices = []
      inner_most      = false
    end
    
    # handle current advice
    if advice.around?
      create_method_for_around_advice klass, method, advice, inner_most
      inner_most = false
    else
      grouped_advices << advice
    end
    
    group = advice.group
  end
  
  # create wrap method for before/after advices which are not wrapped inside around advice.
  unless grouped_advices.empty?
    create_method_for_before_after_advices klass, method, grouped_advices, inner_most unless grouped_advices.empty?
  end
ensure
  @creating_method = nil
end

.create_method_for_around_advice(klass, method, advice, inner_most) ⇒ Object 



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# File 'lib/aspect4r/helper.rb', line 125

def self.create_method_for_around_advice klass, method, advice, inner_most
  code = WRAP_METHOD_TEMPLATE.result(binding)
  # puts code
  klass.class_eval code, __FILE__
end

.create_method_for_before_after_advices(klass, method, advices, inner_most) ⇒ Object 



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# File 'lib/aspect4r/helper.rb', line 178

def self.create_method_for_before_after_advices klass, method, advices, inner_most
  before_advices = advices.select {|advice| advice.before? or advice.before_filter? }
  after_advices  = advices.select {|advice| advice.after?  }
  
  code = METHOD_TEMPLATE.result(binding)
  # puts code
  klass.class_eval code, __FILE__
end

.creating_method? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/aspect4r/helper.rb', line 12

def self.creating_method?
  @creating_method
end

.define_method(klass_or_module, *args, &block) ⇒ Object 



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# File 'lib/aspect4r/helper.rb', line 16

def self.define_method klass_or_module, *args, &block
  @creating_method = true
  klass_or_module.send :define_method, *args, &block
ensure
  @creating_method = false
end

.eigen_class(klass_or_module) ⇒ Object 



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# File 'lib/aspect4r/helper.rb', line 23

def self.eigen_class klass_or_module
  klass_or_module.module_eval do
    class << self
      self
    end
  end
end

.find_available_method_name(klass, method_name_prefix) ⇒ Object 



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# File 'lib/aspect4r/helper.rb', line 5

def self.find_available_method_name klass, method_name_prefix
  0.upto(10000) do |i|
    m = "#{method_name_prefix}#{i}_#{klass.hash}"
    return m unless klass.private_instance_methods(false).include?(m)
  end
end

.process_advice(meta_data, klass_or_module, *methods, &block) ⇒ Object

Store original method in aspect data and refer to it whenever recreating method



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# File 'lib/aspect4r/helper.rb', line 32

def self.process_advice meta_data, klass_or_module, *methods, &block
  methods.flatten!

  options = meta_data.default_options.clone
  options.merge!(methods.pop) if methods.last.is_a? Hash
  options.merge!(meta_data.mandatory_options)
  
  if block_given?
    with_method = find_available_method_name klass_or_module, meta_data.with_method_prefix
    klass_or_module.send :define_method, with_method, &block
    klass_or_module.send :private, with_method
  else
    with_method = methods.pop
  end
  
  a4r_data = klass_or_module.a4r_data
  advice   = Aspect4r::Model::Advice.new(meta_data.advice_type, with_method, a4r_data.group, options)
  
  methods.each do |method|
    method = method.to_sym
    klass_or_module.a4r_data.methods_with_advices << method
    
    aspect = a4r_data[method] ||= Aspect4r::Model::AdvicesForMethod.new(method)
    aspect.add advice
    
    if not aspect.wrapped_method and klass_or_module.instance_methods.include?(method.to_s)
      aspect.wrapped_method = klass_or_module.instance_method(method)
    end
    
    create_method klass_or_module, method if aspect.wrapped_method
  end
end