Frustrating Problem - Acts As Tree

Rails
1

I am a ruby on Rails Novice and I am having an extremely frustrating
problem - not sure whether acts_as_tree plug in is causing this or not
(or me lacking a fundamental misunderstanding of rails)

I have the following table schema:

create_table “destinations”, :force => true do |t|
t.string “name”
t.string “description”
t.integer “commissions_rate”,
:default => 0
t.integer “destinations_count”,
:default => 0
t.integer “position”
t.datetime “created_at”
t.datetime “updated_at”
end

and model def:

class Destination < ActiveRecord::Base
attr_accessible :id, :name, :parent_id, :centre_longitude,
:centre_latitude, :commissions_rate, :position, :startzoom,
:description, :destinations_count

acts_as_tree :counter_cache => true

end

I am trying to adjust the update method in my controller so that if the
parent commissions_rate is modified the “children” records of the parent
are automatically updated with this value, code as follows:

def update
@destination = Destination.find(params[:id])
@rate = @destination.commissions_rate || 0
@children = @destination.children
if (@destination.destinations_count > 0)
for child in @children do
child.commissions_rate = @rate
end
end
respond_to do |format|
if @destination.update_attributes(params[:destination])
flash[:notice] = ‘Destination was successfully updated.’
…
end

The form only send data for the parent model (not using nested model)

Everything works when I test the above code in the Rails console however
when running the server the children are failing to have the
commission_rate variable updated.
Would appreciate any help anyone can provide me.

Thanks

David

2

On 15 February 2010 10:46, David K. [email protected] wrote:

I am a ruby on Rails Novice and I am having an extremely frustrating problem - not sure whether acts_as_tree plug in is causing this or not (or me lacking a fundamental misunderstanding of rails)

Everything works when I test the above code in the Rails console however when running the server the children are failing to have the commission_rate variable updated.
Would appreciate any help anyone can provide me.

You’re not saving the child after you update it’s value

for child in @children do
  child.commissions_rate = @rate
  child.save
end

or

for child in @children do
  child.update_attribute(:commissions_rate,  @rate)
end

.update_attribute automatically saves, check the Rails API docs for
more info on using this method.

PS You’re using a lot of instance variables there, which seem like
there would be better scoped as local variables (ie drop the @ from
the variables unless you need them to be accessible on an instance of
the object - @destination is probably the only legitimate instance
variable)

3

Many thanks Michael, it solved the problem, and thanks for the extra
advice I need it! as where I am based (Indonesia) no one teaches
rails.