Module: Stenotype::Emitter

Defined in:
lib/stenotype/emitter.rb

Overview

An extension for a plain Ruby class in order to track invocation of instance methods.

Constant Summary collapse

ClassMethodsExtension =

Class methods for target to be extended by

Class.new(Module)
InstanceMethodsExtension =

Instance methods to be included into target class ancestors chain

Class.new(Module)

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.build_class_methods(class_mod) ⇒ Object

Adds class method [#emit_klass_event_before] to every class inherited from [Object]



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# File 'lib/stenotype/emitter.rb', line 114

def self.build_class_methods(class_mod)
  class_mod.module_eval <<-RUBY, __FILE__, __LINE__ + 1
    def emit_event_before(*methods)
      proxy = const_get(:InstanceProxy)

      methods.each do |method|
        proxy.module_eval do
          define_method(method) do |*args, **rest_args, &block|
            Stenotype::Event.emit!(
              # @todo How do we name such events?
              "instance_method",
              {
                type: "instance_method",
                class: self.class.name,
                method: __method__,
              },
              eval_context: { klass: self },
            )
            super(*args, **rest_args, &block)
          end
        end
      end

      send(:prepend, proxy)
    end

    def emit_klass_event_before(*class_methods)
      proxy = const_get(:ClassProxy)

      class_methods.each do |method|
        proxy.module_eval do
          define_method(method) do |*args, **rest_args, &block|
            Stenotype::Event.emit!(
              # @todo How do we name such events?
              "class_method",
              {
                type: "class_method",
                class: self.name,
                method: __method__,
              },
              eval_context: { klass: self },
            )
            super(*args, **rest_args, &block)
          end
        end

        singleton_class.send(:prepend, proxy)
      end
    end
  RUBY
end

.build_instance_methods(instance_mod) ⇒ Object

Adds an instance method: [#emit_event] to a target class where Stenotype::Emitter in included in



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# File 'lib/stenotype/emitter.rb', line 93

def self.build_instance_methods(instance_mod)
  instance_mod.module_eval <<-RUBY, __FILE__, __LINE__ + 1
    def emit_event(event_name, attributes = {}, method: caller_locations.first.label, eval_context: nil)
      Stenotype::Event.emit!(
        event_name,
        {
          type: "instance_method",
          class: self.class.name,
          method: method.to_sym,
          **attributes,
        },
        eval_context: (eval_context || { klass: self })
      )
    end
  RUBY
end

.emit_event_before(*methods) ⇒ Object

A class method injected into target class to track instance methods invocation

Examples:

Usage of emit_event_before

class SomeRubyClass
  include Stenotype::Emitter
  emit_event_before :some_method # Triggers an event upon calling some_method

  def some_method
    # do something
  end
end

Parameters:

  • methods (Array<Symbol>) —

    A list of method before which an event will be emitted




# File 'lib/stenotype/emitter.rb', line 56

.emit_klass_event_before(*class_methods) ⇒ Object

A class method injected into a target class to track class methods invocation

Examples:

Usage emit_klass_event_before

class SomeRubyClass
  include Stenotype::Emitter
  emit_klass_event_before :some_method # Triggers an event upon calling some_method

  def self.some_method
    # do something
  end
end

Parameters:

  • class_methods (Array<Symbol>) —

    A list of class method before which an event will be emitted




# File 'lib/stenotype/emitter.rb', line 72

Instance Method Details

#emit_event(name, attributes = {}, method: caller_locations.first.label, eval_context: nil) ⇒ Stenotype::Event

A method injected into target class to manually track events

Examples:

Usage of emit_event

class SomeRubyClass
  include Stenotype::Emitter

  def some_method
    data = collection_data
    emit_event(data, eval_context: self) # Track event with given data
    data
  end
end

Parameters:

  • name ([String, Symbol]) —

    Event name.

  • attributes (Hash) (defaults to: {}) —

    Data to be sent to the targets.

  • method (String) (defaults to: caller_locations.first.label) —

    An optional method name.

  • eval_context (Hash) (defaults to: nil) —

    A hash linking object to context handler

Returns:




# File 'lib/stenotype/emitter.rb', line 35