Loop & output content_tags within content_tag in helper

Question

I\'m trying a helper method that will output a list of items, to be called like so:

foo_list( [\'item_one\', link_to( \'item_two\', \'#\' ) ... ] )


        

Answer 1

You could use content_tag_for, which works with collections:

def foo_list(items)
  content_tag(:ul) { content_tag_for :li, items }
end

Update: In Rails 5 content_tag_for (and div_for) were moved into a separate gem. You have to install the record_tag_helper gem in order to use them.

Answer 2

Along with answers above, this worked for me well:

(1..14).to_a.each do |age|
  concat content_tag :li, "#{link_to age, '#'}".html_safe
end

Answer 3

I couldn't get that work any better.

If you were using HAML already, you could write your helper like this:

def foo_list(items)
  haml_tag :ul do
    items.each do |item|
      haml_tag :li, item
    end
  end
end

Usage from view:

- foo_list(["item_one", link_to("item_two", "#"), ... ])

Output would be correctly intended.

Answer 4

The big issue is that content_tag isn't doing anything smart when it receives arrays, you need to send it already processed content. I've found that a good way to do this is to fold/reduce your array to concat it all together.

For example, your first and third example can use the following instead of your items.map/collect line:

items.reduce(''.html_safe) { |x, item| x << content_tag(:li, item) }

For reference, here is the definition of concat that you're running into when you execute this code (from actionpack/lib/action_view/helpers/tag_helper.rb).

def concat(value)
  if dirty? || value.html_safe?
    super(value)
  else
    super(ERB::Util.h(value))
  end
end
alias << concat

Answer 5

Try this:

def foo_list items
  content_tag :ul do
      items.collect {|item| concat(content_tag(:li, item))}
  end
end