Creating subcategories with acts_as_tree

Rails
1

I’ve been working on my first real RoR project and seemingly everything
is going well except I’m at a loss right now trying to figure out how to
create subcategories.

This is what I have so far:

Database:
Category Table
id
name
parent_id

News Table
id
title
content
category_id

Models:
CATEGORY
acts_as_tree
has_many :news

NEWS
belongs_to category

In my Application Helper I’ve set up the following:

def display_categories(categories)
ret = “

    ”
    for category in categories
    if category.parent_id == 0
    ret += “
  • ”
    ret += link_to category.name
    ret += find_all_subcategories(category)
    ret += “
    • ”
    end
    end
    ret += “
”
end

def find_all_subcategories(category)
if category.children.size > 0
ret = ‘

    ’
    category.children.each { |subcat|
    if subcat.children.size > 0
    ret += ‘
  • ’
    ret += link_to h(subcat.name), :action => ‘edit’, :id => subcat
    ret += find_all_subcategories(subcat)
    ret += ‘
    • ’
    else
    ret += ‘
  • ’
    ret += link_to h(subcat.name), :action => ‘edit’, :id => subcat
    ret += ‘
    • ’
    end
    }
    ret += ‘
’
end
end

In my controller I have set up create for news:
def create
@news = News.new(params[:news])
if @news.save
flash[:notice] = ‘News was successfully created.’
redirect_to :action => ‘list’
else
render :action => ‘new’
end
end

But I’m not sure what to add to this and what to put in my layout to be
able to select what category/subcategory when creating a news item, and
how to create subcategories with-in the parent. If I manually go into
the database and change the id numbers it will display properly, I’m
just confused as how to create.

Thanks for any help… Very much appreciated.