Acts_as_tree: Sorting by full hierarchy

Rails
1

I’m new to RoR, and I’m having trouble sorting a list of categories
using acts_as_tree. Specifically, my list produces something like:

History > Modern > 20th Century
History > United States > 20th Century
Juvenile Fiction > Historical > United States > 20th Century
Juvenile Non-Fiction > History > United States > 20th Century
History > Modern > 21st Century

That’s because I’m sorting by “name,” rather than the full ancestry plus
the name. What I would like to do is produce a list like this:

History > Modern > 20th Century
History > Modern > 21st Century
History > United States > 20th Century
Juvenile Fiction > Historical > United States > 20th Century
Juvenile Non-Fiction > History > United States > 20th Century

For the life of me, I can’t figure out how to sort on the “long name”
(ancestry + name). Everything I try seems to error out.

For background information, my model looks like this:

class Category < ActiveRecord::Base
acts_as_tree

def ancestors_name
if parent
parent.ancestors_name + parent.name + ’ > ’
else
“”
end
end

def long_name
ancestors_name + name
end

end

The pertinent parts of my controller look like this:

class CategoriesController < ApplicationController

def list
@all_categories = Category.find(:all, :order => “name”)
end

And the list.rhtml looks like this:

Listing categories

<% for category in @all_categories %>
<tr>
    <td><%=h category.long_name %></td>
<td><%= link_to 'Edit', :action => 'edit', :id => category %></td>
<td><%= link_to 'Destroy', { :action => 'destroy', :id => category

}, :confirm => ‘Are you sure?’, :method => :post %>

<% end %>
Name

<%= link_to ‘New category’, :action => ‘new’ %>

Of course, I would like to do a lot more with this than just the list,
but if I can figure out how to do the list, I should be able to figure
out the rest.

Any help would be most appreciated!

2

Larry Lutz wrote:

the name. What I would like to do is produce a list like this:

History > Modern > 20th Century
History > Modern > 21st Century
History > United States > 20th Century
Juvenile Fiction > Historical > United States > 20th Century
Juvenile Non-Fiction > History > United States > 20th Century

For the life of me, I can’t figure out how to sort on the “long name”
(ancestry + name). Everything I try seems to error out.

Try adding nested set capability to your category model.
Then get depth-first order by sorting by the “lft” field.

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