Class: DSLCompose::Parser::ForChildrenOfParser::ForDSLParser

Inherits:
Object
  • Object
show all
Defined in:
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, DSLDoesNotExistError, DSLNamesShouldBeSymbolsError, ForMethodParser, NoBlockProvided

Instance Method Summary collapse

Constructor Details

#initialize(base_class, child_class, dsl_names, on_current_class, on_ancestor_class, first_use_only, &block) ⇒ ForDSLParser

This class will yield to the provided block once for each time a DSL of the provided name is used by the child class.

base_class and child_class are set from the ForChildrenOfParser



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# File 'lib/dsl_compose/parser/for_children_of_parser/for_dsl_parser.rb', line 23

def initialize base_class, child_class, dsl_names, on_current_class, on_ancestor_class, first_use_only, &block
  @base_class = base_class
  @child_class = child_class
  @dsl_names = dsl_names

  # 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_dsl :dsl_name do |dsl_name:|`"
    end
  end

  # if the provided dsl name is a symbol, then convert it to an array
  if dsl_names.is_a? Symbol
    dsl_names = [dsl_names]
  end

  # assert that the provided dsl name is an array
  unless dsl_names.is_a? Array
    raise DSLNamesShouldBeSymbolsError, "DSL names `#{dsl_names}` must be provided with a symbol or array of symbols"
  end

  # assert that the provided dsl name is an array of symbols
  unless dsl_names.all? { |dsl_name| dsl_name.is_a? Symbol }
    raise DSLNamesShouldBeSymbolsError, "DSL names `#{dsl_names}` must be provided with a symbol or array of symbols"
  end

  # assert that the provided dsl names all exist
  unless dsl_names.all? { |dsl_name| DSLs.class_dsl_exists?(base_class, dsl_name) }
    raise DSLDoesNotExistError, "DSLs named `#{dsl_names}` must all exist"
  end

  # for each provided dsl name, yield to the provided block
  dsl_names.each do |dsl_name|
    # a dsl can be execued multiple times on a class, so we find all of the executions
    # here and then yield the block once for each execution
    base_class.dsls.class_dsl_executions(child_class, dsl_name, on_current_class, on_ancestor_class, first_use_only).each do |dsl_execution|
      # we only provide the requested arguments to the block, this allows
      # us to use keyword arguments to force a naming convention on these arguments
      # and to validate their use
      args = {}

      # the dsl name (if it's requested)
      if BlockArguments.accepts_argument?(:dsl_name, &block)
        args[:dsl_name] = dsl_execution.dsl.name
      end

      # the dsl_execution (if it's requested)
      if BlockArguments.accepts_argument?(:dsl_execution, &block)
        args[:dsl_execution] = dsl_execution
      end

      # a hash representation of all the dsl arguments, if requested
      if BlockArguments.accepts_argument?(:dsl_arguments, &block)
        args[:dsl_arguments] = {}
        # process each argument, because we might need to coerce it
        dsl_execution.arguments.arguments.each do |name, value|
          # if this value is a ClassCoerce object, then convert it from its original
          # string value to a class
          args[:dsl_arguments][name] = value.is_a?(ClassCoerce) ? value.to_class : value
        end
      end

      # an ExecutionReader object to access the exections methods (if it's requested)
      if BlockArguments.accepts_argument?(:reader, &block)
        args[:reader] = Reader::ExecutionReader.new(dsl_execution)
      end

      # add any arguments that were provided to the DSL
      dsl_execution.arguments.arguments.each do |name, value|
        if BlockArguments.accepts_argument?(name, &block)
          # if this value is a ClassCoerce object, then convert it from its original
          # string value to a class
          args[name] = value.is_a?(ClassCoerce) ? value.to_class : value
        end
      end

      # set the dsl_execution in an instance variable so that method calls to `for_method`
      # from within the block will have access to it
      @dsl_execution = dsl_execution
      # yield the block in the context of this class
      instance_exec(**args, &block)
    rescue => e
      # if this is an InterpreterError, then it already has the called_from metadata
      # just continue raising the original error
      if e.is_a? Interpreter::InterpreterError
        raise
      end
      # otherwise, decorate the error with where the DSL was defined
      raise e, "#{e.message}\nparsing class: #{child_class.name}\ndsl name: #{dsl_name}\ndsl source: #{dsl_execution.called_from}", e.backtrace
    end
  end
end