Class: ObservableDelegate

Inherits:
Object
  • Object
show all
Includes:
Observable
Defined in:
lib/observable-delegate/version.rb,
lib/observable-delegate/observable_delegate.rb

Constant Summary collapse

VERSION = 
'0.0.1'

Instance Method Summary collapse

Constructor Details

#initialize(subject, notify_with: nil, observe: [], delegate: []) ⇒ ObservableDelegate

Returns a new instance of ObservableDelegate.



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# File 'lib/observable-delegate/observable_delegate.rb', line 6

def initialize(subject, notify_with: nil, observe: [], delegate: [])
  @subject = subject
  @notify_with = notify_with
  @observe_methods = observe
  @delegate_methods = delegate
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method

#method_missing(method, *args, &block) ⇒ Object 



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# File 'lib/observable-delegate/observable_delegate.rb', line 13

def method_missing(method, *args, &block)
  if should_delegate?(method) && should_notify?(method)
    result = @subject.send(method, *args, &block)

    changed

    payload = if @notify_with
      @subject.send(@notify_with)
    else
      result
    end

    notify_observers(payload)

    result
  elsif should_delegate?(method)
    @subject.send(method, *args, &block)
  else
    # create a no method error here and remove the
    # last backtrace from it so that it points to
    # where this method was used.
    begin
      raise NoMethodError.new("No method #{method} found for #{@subject.class}")
    rescue NoMethodError => e
      e.set_backtrace(e.backtrace[1..-1])
      raise e
    end
  end
end

Instance Method Details

#should_delegate?(method) ⇒ Boolean

should delegate if the subject has the method and the method is explicitly provided or there are not methods explicitly provided

Returns:



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# File 'lib/observable-delegate/observable_delegate.rb', line 46

def should_delegate?(method)
  @subject.methods.include?(method) &&
    (@delegate_methods.include?(method) ||
     @delegate_methods.empty?)
end

#should_notify?(method) ⇒ Boolean

should notify if the method is explicitly provied or no methods are explicitly provided

Returns:



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# File 'lib/observable-delegate/observable_delegate.rb', line 54

def should_notify?(method)
  @observe_methods.include?(method) || @observe_methods.empty?
end