HAML filters in a helper

Question

Helper functions can receive a block which they yield to render the block. Sometimes I'd want that block to be spec'd with a filter. So for example:

= doc_page title: 'FAQ' do
  :markdown
    # Welcome to the *FAQ*

This is not so DRY as we are always writing doc_page and markdown together. Can I make the helper method accept a block and pass it through a HAML filter. Something like:

= doc_page title: 'FAQ' do
  # Welcome to the *FAQ*

In this fantasy, doc_page is a helper method that does some setup stuff and then passes the content through markdown, saving us the need to declare :markdown everywhere and making the world a DRYer place.

Answer 1

Currently it is not possible to use filters in helpers. An alternative approach would be to use redcarpet to parse the markdown and then pass the output to a helper.

an example would be:

= doc_page title: 'FAQ', :markdown do
  ### my markdown

= doc_page title: 'FAQ' do
  normal html

The implementation of the doc_page would be something like this:

def doc_page(title, markup=:html)

  content = yield

  if markup == :markdown
    markdown = Redcarpet::Markdown.new(Redcarpet::Render::HTML)
    content = markdown.render(content)
  end

  content
end

This would solve your problem, as you define your markdown filter in the helper. And you don't need an extra indentation level in your haml.