Works

named_scope :public, :conditions => "public = true"

Works

PUBLIC_CONDITIONS = "public = true"
named_scope :public, :conditions => SomeModel::PUBLIC_CONDITIONS

Works

named_scope :public, lamba { {:conditions => SomeModel.public_conditions} }
def self.public_conditions...

In the third example there is no sense to set onchange event since it will never happen...

If you're on Rails 3, you should look into http://apidock.com/rails/ActiveRecord/Relation/update_all

If you have

class Topic < ActiveRecord::Base
default_scope :conditions => "forums.preferences > 1", :include => [:forum]
end

and you do a

Topic.update_all(...)

it’ll fail with

Mysql::Error: Unknown column 'forums.preferences' in 'where clause'

The work around for this is:...

==== Code example

Google = Struct.new(:address) do
def latitude
  -1
end

def longitude
  -2
end

def with_address
  "with #{address}"
end
end

g = Google.new("Some Addres")

puts g.address
puts g.latitude
puts g.longitude
puts...

If you remove any values from the batch, the while loop in find_in_batches breaks even if there are additional batches:

People.count # => 3000

People.find_in_batches do |peeps|
peeps.reject!(&:bad?)
# ... more operations on peeps
puts 'Tick'
end

Running the above code, you...

When you create a nested form, and want the main object to validate all nested models, you should make all the nested models dirty or validations will not run upon them.

class Order < ActiveRecord::Base
has_many :order_lines
accepts_nested_attributes_for :order_lines

before_vali...

I inherited some code that used form_remote_tag. send_file and send_data did not work.

Changing from from_remote_tag to form_tag and all worked as expected.

Rails.env

or possibly:

ActionController::TestRequest.new (which has a demo of how to set env vars on a controller test)

This method relies on #blank? to determine if the attribute is valid.

When you call #blank? on an ActiveRecord object, it returns true as long as there are no changes to the object.

So you can validate the base attribute (i.e.: product_id), but you'll have no guarantee that it points to a valid re...

See the documentation for link_to_remote to see the common AJAX options, like +:before+ and +:completed+.

====
Person.sum(:age, :group => "sex") # =>[["male",2500],["female",2200]]

====
Person.sum(:age, :group => "sex") # =>[["male",2500],["female",2200]]

What is documented here about Rails parameter extraction always getting the first occurrence of a key is apparently incorrect (in Rails 2.3 it gets the last occurrence).

See the following email thread on [rubyonrails-core]:

http://www.mail-archive.com/[email protected]/msg08719.htm...

I had to add "self.inheritance_column" as opposed to simply "inheritance_column" to get this to work.

==== Code example
class MyModel < ActiveRecord::Base # disable STI self.inheritance_column = :_type_disabled end

For Rails 3 see ActionDispatch::Routing::UrlFor#url_for

I've been upgradings an app to Rails 3 and it took me a bit to find this-

If you were using

include ActionController::UrlWriter

to get the url helpers in rails 2, you should switch to

include Rails.application.routes.url_helpers 

for Rails 3

From: http://snipplr.com/view/37063...

To configure caching of f.ex. a :mem_cache_store you can pass additional parameters just after the cache type symbol:

ActionController::Base.cache_store = \\
:mem_cache_store, 'a.example.org:11211', 'b.example.org:11211'

all parameters after the cache type symbol will be passed on to the c...

If you want to pass in parameters you can do it like this:

User.get(:find_by_name, headers = {:name => "bob"})
=> /users/find_by_name.xml?name=bob

For nested routes...

routes.rb resources :companies do resources :users do member do get :find_by_name end en...

If you want to throw the exception after rolling back you can do something like this:

Company.transaction do
user.save
company.save
x = 1/0
rescue
exp = $!
begin
  raise ActiveRecord::Rollback
rescue
end
raise exp
end