Ruby On Rails acts_as_tree select menu
This time I would like to share a helper I wrote for rails. I was trying to write a form to add categories and I wanted to present a neatly formatted select box of existing categories to select as the parent category. It also needed infinite nested subcategories. I could not find a tutorial or example code anywhere for what I was trying to do. So I wrote this little snippet.
application_helper.rb:
def tree_select(categories, model, name, selected=0, level=0, init=true)
html = ""
# The "Root" option is added
# so the user can choose a parent_id of 0
if init
# Add "Root" to the options
html << "
\\n" if init
return html
end
View:
<%= tree_select(Category.find(:all, :conditions => "parent_id = 0"),
'category', 'parent_id', @category) %>
Great helper! Thanks a lot!
February 21, 2008 at 11:53 pm
Perfect – just what I was looking for!
March 15, 2008 at 1:35 pm
There’s nobody I like more than the man who saves me time. Great post. Thanks for writing the snippit.
April 15, 2008 at 7:14 am
really cool! thanx!
December 23, 2008 at 11:55 am
This tag works wonderfully when editing records within the Category table. However, I need help making it work on my Tag table. My Tag table
belongs_to :category
I can get the select menu to display the existing tree of Cateogries, but not to select the preset value in the Tag table record’s “category_id” cell.
Any help you can supply would be appreciated.
January 4, 2009 at 11:57 pm
I figured this out. I just removed your “def tree_select” from the “application_helper.rb” file, and then placed it elsewhere with minor edits as follows:
1) I put it on the “categories_helper.rb” just as you had written it, with your two references to “selected.parent_id”.
2) I then put a slightly modified version of it on the other “…_helper.rb” templates where I want to use it, but replaced the “selected.parent_id” with “selected.id”. You can leave it as “selected.parent_id”, but will see that it selects the next higher node on the tree branch.
Note that one must remove the code from the “application_helper.rb” in order for this distributed instance model to work.
Your code is very sweet, and I thank you muchly!
January 6, 2009 at 11:03 am
Also, on the particular helper pages I replaced
html \n”
with hard-coded field “name” and “id”
html \n”
This one is for the “category_id” field on the “tag” helper.
January 6, 2009 at 11:53 am
Thank you for your item.
Note: In Rails with SQLite3
:conditions => “parent_id = 0″
replace by this:
:conditions => “parent_id IS NULL “
February 21, 2009 at 10:00 am
Sweet! After stumbling over it a little, I managed to get it. Thanks a million, George!
May 18, 2009 at 3:20 am
Much thanks for sharing this – I was just about to try to hack out something myself and am VERY happy not to have to do all that work
May 23, 2009 at 10:19 pm
def tree_options_for_select(categories, selected=nil, level=0)
result = ”
# if level==0
# end
categories.each do |c|
result #{c.name}”
result
August 17, 2009 at 3:30 am
def tree_options_for_select(categories, selected=nil, level=0)
result = ”
# if level==0
# end
categories.each do |c|
result #{c.name}”
result
August 17, 2009 at 3:31 am
I really liked your solution, thanks for this post
September 16, 2009 at 6:45 am