Notes

Since 1.9 introduces native threads, we cannot assume the order of exectution and the example above is not thread safe and fails with a "deadlock detected (fatal)" error. Also Thread.pass is pointless in the context of native threads.

This will work as intended with native threads:

a = Thread....

If you're actually looking to cut down on code why not use .map instead of the longer .collect?

HTML5 officially supports block-level elements in the anchor tag and Rails 3 allows you to pass a block to image_tag:

<%= image_tag(some_path) do %> <%= content_tag(:p, "Your link text here") <% end %>

If you want to have only the path prefix without namespacing your controller, pass :module => false.

Normal:

namespace :account do
  resources :transactions, :only => [:index]
end

account_transactions GET /account/transactions(.:format)
{:controller=>"account/transactions", :a...

%e - Day of the month, without leading zero (1..31)

"In Ruby 1.9 and newer mb_chars returns self'"

This would seem to be a lie. At least in rails 3.1.0 and ruby 1.9.2, mb_chars still returns a proxy object with additional useful methods defined on it that aren't on a 1.9.2 String.

ruby-1.9.2-p180 :007 >  "àáâãäå".normalize(:kd)
NoMethodE...

Useful for when you need to create a Date object from these manually, such as for reporting.

If the date select input is start_date and it belongs to the report form object:

@start_date = Date.civil(params[:report]["start_date(1i)"].to_i,...

does it?

replace(klass.find(ids).index_by { |r| r.id }.values_at(*ids))

equals replace(klass.find(ids))

I see no point in making it that complicated

The example of adding to an array without effecting superclass:

# Use setters to not propagate changes:
Base.setting = []
Subclass.setting += [:foo]

That's right as far as it goes. But beware when you are in context of class definition:

class Subclass < Base
   # possibly wron...

You can find the selected option (or options for multiple select inputs) with the following:

assert_select('select#membership_year option[selected]').first['value']

Actually, use model_instance.errors.add :base, :invalid to have I18n working.

useful options are:

:root => 'object', :skip_instruct => true, :indent => 2

:builder can also be used to pass your own Builder::XmlMarkup instance.

When using Array as default value, it behaves more like cattr_accessor...

class A

attr_accessor_with_default :b, [] end

x = A.new
x.b << 1

#puts x.b.inspect => [1]

y = A.new
y.b << 2

#puts y.b.inspect => [1, 2]

Time.now.advance(:days => +2, :hours => +8)

The first code example may be simplified, since the call to method to_xml is made implicitly anyway:

def index @people = Person.find :all

respond_to do |format| format.html format.xml { render :xml => @people } end end

Per http://ar.rubyonrails.org/classes/ActiveRecord/Callbacks.html "If a before_* callback returns false, all the later callbacks and the associated action are cancelled. If an after_* callback returns false, all the later callbacks are cancelled." [and presumably associated action is not canceled]...

It is possible to pass an instance of a record to the method. See the documentation of polymorphic_url (http://apidock.com/rails/ActionDispatch/Routing/PolymorphicRoutes).

Thought it would be best to take the source code from pluralize and just remove the count from the output.

Create this helper method in application_helper.rb

# Pluralize without showing the count.
def simple_pluralize count, singular, plural=nil
((count == 1 || count =~ /^1(\\.0+)?$/...

If you are using this to validate that a has_one association has been made with another object this will not work, as the test used in the AssociatedValidator #validates_each method tests for nil and then ignores this object.

To test for association with a has_one association you can use the follow...

See: http://apidock.com/rails/ActionView/Helpers/FormTagHelper/number_field_tag