Rails局部和HAML

Question

I have a ajax method that renderes a @collection of users. This code is from the users partial. Now what I need to do is wrap a ul tag around the 3 li tags for every third object. How do I do this with HAML? I can't just add the %ul tag to "when 1" - because HAML closes the tag when that object has been rendered.

-case user_counter + 1
-when 1
  %li.first
    @user.login
-when 2
  %li
    @uer.login
-when 3
  %li.last
    @user.login

This is the result I am looking for:

<ul>
  <li>user1</li>
  <li>user2</li>
  <li>user3</li>
</ul>

<ul>
  <li>user4</li>
  <li>user5</li>
  <li>user6</li>
</ul>

etc.

Answer 1

I think you want each_slice . It splits an Enumerable into groups of a specified size. You could do something like:

- @collection.each_slice(3) do |slice|
  %ul
    %li.first= slice[0].login
    %li= slice[1].login
    %li.last= slice[2].login

Answer 2

This should be functionally equivalent to Chuck's answer, just a tad shorter.

I prefer the simplicity in Chuck's answer, but this does work as well.

- @collection.each_slice(3) do |slice|
  %ul
    - slice.zip([:first,nil,:last]).each do |user, klass|
      %li{:class => klass}= user.login