Class: DSLCompose::Parser::ForChildrenOfParser

Inherits:
Object
  • Object
show all
Defined in:
lib/dsl_compose/parser/for_children_of_parser.rb,
lib/dsl_compose/parser/for_children_of_parser/descendants.rb,
lib/dsl_compose/parser/for_children_of_parser/for_dsl_parser.rb,
lib/dsl_compose/parser/for_children_of_parser/for_dsl_parser/for_method_parser.rb

Defined Under Namespace

Classes: AllBlockParametersMustBeKeywordParametersError, ClassDoesNotUseDSLComposeError, Descendants, ForDSLParser, NoBlockProvided, NoChildClassError

Instance Method Summary collapse

Constructor Details

#initialize(base_class, final_children_only, skip_classes = [], &block) ⇒ ForChildrenOfParser

This class will yield to the provided block for each descendant class of the provided base_class

For example:

class BaseClass

include DSLCompose::Composer
define_dsl :my_foo_dsl

end

class ChildClass < BaseClass

my_foo_dsl

end

class GrandchildClass < ChildClass end

parser.for_children_of BaseClass do |child_class:|

# this will yield for ChildClass and GrandchildClass

and



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# File 'lib/dsl_compose/parser/for_children_of_parser.rb', line 38

def initialize base_class, final_children_only, skip_classes = [], &block
  # assert the provided class has the DSLCompose::Composer module installed
  unless base_class.respond_to? :dsls
    raise ClassDoesNotUseDSLComposeError, base_class
  end

  @base_class = base_class

  # assert that a block was provided
  unless block
    raise NoBlockProvided
  end

  # if any arguments were provided, then assert that they are valid
  if block&.parameters&.any?
    # all parameters must be keyword arguments
    if block.parameters.filter { |p| p.first != :keyreq }.any?
      raise AllBlockParametersMustBeKeywordParametersError, "All block parameters must be keyword parameters, i.e. `for_children_of FooClass do |base_class:|`"
    end
  end

  # yeild the block for all descendants of the provided base_class
  Descendants.new(base_class, final_children_only, skip_classes).classes.each do |child_class|
    # determine which arguments to send to the block
    args = {}
    if BlockArguments.accepts_argument?(:child_class, &block)
      args[:child_class] = child_class
    end

    # set the child_class in an instance variable so that method calls to
    # `for_dsl` from within the block will have access to it
    @child_class = child_class

    # yield the block in the context of this class
    instance_exec(**args, &block)
  end
end