Method: RubyPython::RubyPyProxy#method_missing

Defined in:
lib/rubypython/rubypyproxy.rb

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

Delegates method calls to proxied Python objects.

Delegation Rules

  1. If the method ends with a question-mark (e.g., nil?), it can only be a Ruby method on RubyPyProxy. Attempt to reveal it (RubyPyProxy is a BlankObject) and call it.

  2. If the method ends with equals signs (e.g., value=) it’s a setter and we can always set an attribute on a Python object.

  3. If the method ends with an exclamation point (e.g., foo!) we are attempting to call a method with keyword arguments.

  4. The Python method or value will be called, if it’s callable.

  5. RubyPython will wrap the return value in a RubyPyProxy object (unless legacy_mode has been turned on).

  6. If a block has been provided, the wrapped return value will be passed into the block.

Raises:

  • (NoMethodError) 


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# File 'lib/rubypython/rubypyproxy.rb', line 142

def method_missing(name, *args, &block)
  name = name.to_s

  if name =~ /\?$/
    begin
      RubyPyProxy.reveal(name.to_sym)
      return self.__send__(name.to_sym, *args, &block)
    rescue RuntimeError => exc
      raise NoMethodError.new(name) if exc.message =~ /Don't know how to reveal/
      raise
    end
  end

  kwargs = false

  if name =~ /=$/
    return @pObject.setAttr(name.chomp('='),
                            PyObject.convert(*args).first)
  elsif name =~ /!$/
    kwargs = true
    name.chomp! "!"
  end

  raise NoMethodError.new(name) if !@pObject.hasAttr(name)

  pFunc = @pObject.getAttr(name)

  if pFunc.callable?
    if args.empty? and pFunc.class?
      pReturn = pFunc
    else
      if kwargs and args.last.is_a?(Hash)
        pKeywords = PyObject.convert(args.pop).first
      end

      orig_args = args
      args = PyObject.convert(*args)
      pTuple = PyObject.buildArgTuple(*args)
      pReturn = if pKeywords
        pFunc.callObjectKeywords(pTuple, pKeywords)
      else
        pFunc.callObject(pTuple)
      end

      # Clean up unused Python vars instead of waiting on Ruby's GC to
      # do it.
      pFunc.xDecref
      pTuple.xDecref
      pKeywords.xDecref if pKeywords
      orig_args.each_with_index do |arg, i|
        # Only decref objects that were created in PyObject.convert.
        if !arg.kind_of?(RubyPython::PyObject) and !arg.kind_of?(RubyPython::RubyPyProxy)
          args[i].xDecref
        end
      end

      raise PythonError.handle_error if PythonError.error?
    end
  else
    pReturn = pFunc
  end

  result = _wrap(pReturn)

  if block
    block.call(result)
  else
    result
  end
end