cycle
cycle(first_value, *values)
public
Returns a Cycle object whose to_s value cycles through items of an array every time it is called. This can be used to alternate classes for table rows:
<%- for item in @items do -%> <tr class="<%= cycle("even", "odd") %>"> ... use item ... </tr> <%- end -%>
You can use named cycles to prevent clashes in nested loops. You’ll have to reset the inner cycle, manually:
<%- for item in @items do -%> <tr class="<%= cycle("even", "odd", :name => "row_class") <td> <%- for value in item.values do -%> <span style="color:'<%= cycle("red", "green", "blue" :name => "colors") %>'"> item </span> <%- end -%> <%- reset_cycle("colors") -%> </td> </tr> <%- end -%>
Cycle with first and last
I needed a cycle that was also aware of the first and last items in the collection. This is adapted from a snippet I found while Googling:
def cycle_with_first_last(object, collection, options = { }) addition = "" addition += " #{options[:first]}" if object == collection.first addition += " #{options[:last]}"if object == collection.last cycle(options[:odd], options[:even]) + addition end
Just put that in your helpers…
CSS columns
You can also use this in a partial to create blocks of content into columns without setting a fixed height. This one is two columns.
.clear { clear: both;} .block { float:left;width:200px;} <div class="block">
<p>Content Item</p>
</div> <%= cycle("", "<div class=\"clear\"></div>") -%>