A simple component class for Rails

component_presenter.rb

# Your component classes can inherit from this
class ComponentPresenter
  # A 'macro' to define the partial path at the top of the class like:
  #   partial_path: 'components/popover'
  # Or just define your own partial_path method
  #
  def self.partial_path(path)
    define_method(:partial_path) do
      path
    end
  end

  attr_reader :template

  # What rails will call when you have something like
  # <%= render(MyComponent.new(args)) %>
  # in a view.
  #
  # This sets template which you can use to call Rails view helpers or your
  # own helpers, like `template.content_tag`.
  def render_in(template, *_args, &_block)
    @template = template

    if render?
      template.render(partial: partial_path, locals: locals)
    else
      ""
    end
  end

  # Overwrite in children to control rendering
  # This is borrowed straight from ViewComponent
  def render?
    true
  end

  # Passed to the partial
  def locals
    {}
  end
end