Notes

To rollback the transaction...

transaction do
unless user.save && company.save
   raise raise ActiveRecord::Rollback
end
end

Or - catch anonymous exceptions, roll back and re-throw error

transaction do
user.save
company.save
x = 1/0
rescue
exp = $!...

I went back and looked at my notes from my previous project.

Yep, these methods were removed from ActiveRecord::Base in an early version, and moved into a Module called AttributeMethods, which is then included in ActiveRecord::Base.

So the methods are available in ActiveRecord::Base... but they ar...

THAiSi, and any others wondering this as well:

I've done some pretty extensive digging in to the rails code, for a couple of projects, and I've found that there are several methods that don't appear in APIDock. There are several reasons for this, but I'm not sure read_attribute falls under any of...

After calling reset on an association, it will be forced to be reloaded next time it's referenced. Useful after you manipulate an associated object/collection with SQL, and you want to make sure subsequent uses don't get the invalid cached version. Better than reload in that it doesn't actually relo...

The Link above doesnt work anymore. This one should be the new one: http://redcloth.org/

According to compute_asset_host as of rails 2.0.0 the %d expansion works in the same way, it's not a random number generated on each call but the source hash mod 4.

In my brief testing in rails 2.3.9, %d doesn't appear to work if you use a Proc, so manual generation is of use in that case.

If you are using Active Record, use a locale file like the one below to change a model's attribute's human name.

en:
activerecord:
  attributes:
    picture:
      explanation: Description

Without using the locale file:

ruby-1.9.2-p0 > Picture.human_attribute_name("explan...

If you need add complex conditions you can use this:

Model.where(:foo => 'bar').where(:attr => 1).update_all("author = 'David'")

Using rails 2.3.8 I kept getting an exception when i tried:

add_index :widgets, [:colour, :weight], :name => :index_by_colour_weight

it's solved by using:

add_index :widgets, [:colour, :weight], :name => 'index_by_colour_weight'

You can now add html options to select options by creating a container with items like the following: ==== Code Example ['display','value',:class => 'option_class']

This will produce: ==== Code Example display

ActionController::Steaming => ActionController::Streaming

In Rails 3, this has moved to ActionDispatch::Routing::PolymorphicRoutes[http://apidock.com/rails/ActionDispatch/Routing/PolymorphicRoutes/polymorphic_url].

It's easy to overlook the :accept option which dictates that the attribute shall be '1', not 'yes', not true, but '1' only for validation to pass.

For '1' shall the value be, no more, no less. '1' shall be the value thou shalt validate, and thy validation shall check for '1'. '2' shalt not thou val...

When the link_to_if condition is false you can get this helper to display nothing by doing something like this

<%= link_to_if(message.user, 'Poster', message.user){} %>

^ That will display nothing if message.user does not exist.

Returns the extension including the '.'.

E.g.

Pathname("/path/to/file.rb").extname
#=> ".rb"

because you can pass inline procs as well:

before_filter {authorize(args)}

====Code def breaking_word_wrap(text, *args) options = args.extract_options! unless args.blank? options[:line_width] = args[0] || 80 end options.reverse_merge!(:line_width => 80) text = text.split(" ").collect do |word| word.length > options[:line_wi...

Documentation for this module (taken from ActiveSupport 3.0.1):

# A typical module looks like this
#
#   module M
#     def self.included(base)
#       base.send(:extend, ClassMethods)
#       base.send(:include, InstanceMethods)
#       scope :foo, :conditions => { :cre...

In Rails 3 - this validation is moved to the HelperMethods

Just adding to what @diabolist said :

class House has_many :doors accepts_nested_attributes_for :doors

attr_accesible :address, :doors_attributes
# NOTE its plural

end