Method: CfnDsl::Types.define_array_method

Defined in:

lib/cfndsl/types.rb

.define_array_method(klass, singular_method, type, variable) ⇒ Object

# File 'lib/cfndsl/types.rb', line 217

def self.define_array_method(klass, singular_method, type, variable)
  type.class_eval do
    CfnDsl.method_names(singular_method).each do |method_name|
      define_method(method_name) do |value = nil, *rest, fn_if: nil, &block|
        existing = instance_variable_get(variable)
        # For no-op invocations, get out now
        return existing if value.nil? && rest.empty? && !block

        # We are going to modify the value in some
        # way, make sure that we have an array to mess
        # with if we start with nothing
        existing ||= instance_variable_set(variable, [])

        # special case for just a block, no args
        if value.nil? && rest.empty? && block
          val = klass.new
          existing.push(fn_if ? FnIf(fn_if, val, Ref('AWS::NoValue')) : val)
          val.instance_eval(&block)
          return existing
        end

        # Glue all of our parameters together into
        # a giant array - flattening one level deep, if needed
        array_params = []
        if value.is_a?(Array)
          array_params.concat(value)
        else
          array_params.push value
        end

        rest.each do |v|
          if v.is_a?(Array)
            array_params.concat(rest)
          else
            array_params.push v
          end
        end
        # Here, if we were given multiple arguments either
        # as method [a,b,c], method(a,b,c), or even
        # method( a, [b], c) we end up with
        # array_params = [a,b,c]
        #
        # array_params will have at least one item
        # unless the user did something like pass in
        # a bunch of empty arrays.
        if block
          array_params.each do |array_params_value|
            value = klass.new
            existing.push(fn_if ? FnIf(fn_if, value, Ref('AWS::NoValue')) : value)
            # This line never worked before, the useful thing to do is pass the array value to the block
            value.instance_exec(array_params_value, &block)
          end
        else
          # List of parameters with no block -
          # hope that the user knows what he is
          # doing and stuff them into our existing
          # array
          array_params.each do |v|
            existing.push v
          end
        end
        return existing
      end
    end
  end
end