Possible to embed markdown within erb?

Question

If you use haml as rails view template, you can write portion of your page using markdown by using the ":markdown" filter.

Is is possible to do the same using erb?

Answer 1

ERB does not have filtering like this built-in. You'll need to directly use a gem that handles it, like RDiscount or the venerable BlueCloth.

Answer 2

It's pretty easy to write a method that does it, assuming you're using something like Rails which has #capture, #concat, and #markdown helpers. Here's an example, using Maruku:

def markdown_filter(&block)
  concat(markdown(capture(&block)))
end

Then you can use this as so:

<% markdown_filter do %>
# Title

This is a *paragraph*.

This is **another paragraph**.
<% end %>

There are a few things to note here. First, it's important that all the text in the block have no indentation; you could get around this by figuring out the common indentation of the lines and removing it, but I didn't do that in the example helper above. Second, it uses Rails' #markdown helper, which could easily be implemented in other frameworks as so (replacing Maruku with your Markdown processor of choice):

def markdown(text)
  Maruku.new(text).to_html
end

Finally, it would work a little differently in Rails 3, since Rails 3 allows block helpers to return strings. Here's how it would be written there:

def markdown_filter(&block)
  markdown(capture(&block)).html_safe
end

And used as so:

<%= markdown_filter do %>
# Title

This is a *paragraph*.

This is **another paragraph**.
<% end %>