Notes

In Ruby 1.8.7, the reported method names were those of the methods actually invoked, so if #b was an alias for #a, and #b was called, it would be reported as "... in b'". In Ruby 1.9, the same invocation is now reported as "... in a'".

Unfortunately, this change disables the hack that could forme...

There has been some indication that callee is intended to return the symbol with which the method was actually invoked, whereas method returns name with which the method was originally defined, but callee actually behaves identically to method in Ruby 1.9.1 1.9.2, and 1.9.3.

This di...

Note that in the example shown in the documentation, user.assign_attributes({ :name => 'Josh', :is_admin => true }) would raise a ActiveModel::MassAssignmentSecurity::Error and would not actually update user.name, contrary to what the example seems to demonstrate.

To block all mass assignments on a model, it's as simple as having an empty list of accessible attributes. ===== example

class Users < ActiveRecord::Base
 attr_accessible #none
end

In Rails 3.X console:

Rails.application.routes.recognize_path('/my_path')

Possible with following snippet of code (for instance if each branch has some different controller logic, but if the controller is not present, it should fallback to default controller).

Advantages are so we do not have to make blank inherited controllers and routes for them, to do it with plain in...

Emails need a fully qualified URL (with domain). Use the +:host+ parameter.

But note also that you need to specify a value that is not dependent upon the request context. http://api.rubyonrails.org/classes/ActionMailer/Base.html recommends setting a default host in +application.rb+ For those o...

There is an excellent guide on the use of this method located here:

http://guides.rubyonrails.org/active_record_querying.html#conditions

First of all, get all the necessary SES credentials and verify your email address.

Then, just edit your config/environments/*.rb files:

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  address: 'email-smtp.us-east-1.amazonaws.com',
  user_name...

in rails3 StatusCodes have been moved to Rack::Utils

You can use a setter with merge:

self.settings = settings.merge(key => value)

Reply to tvle83 and pgmcgee: the destructiveness of this method depends on your database. Some databases are better at converting between disparate types than others. For example, when changing a column from a numeric type to a string type, some databases drop the data where others will turn the num...

For those favoring YAML outputs, this methods simply and recursively outputs the keys and values in YAML (into a String) for your pleasure.

In section 'Bi-directional associations' an example:

d = Dungeon.first

t = d.traps.first

d.level == t.dungeon.level # => true

d.level = 10

d.level == t.dungeon.level # => false

Then use has_many associations, but lower than written 'for belongs_to associations has_many inverse associations are...

The logic for #try is shared between this method and Object#try – “Show source” here doesn’t show the whole story. Both methods are currently implemented in the file activesupport/lib/active_support/core_ext/object/try.rb .

If you click “Show source” here, you may get confused. The logic for #try is shared between this method and NilClass#try . Both versions are currently implemented in the file activesupport/lib/active_support/core_ext/object/try.rb .

This is pretty nice method allowing you to build stuff in a functional way.

Lets say you want to build a hash from an array, keyed by array object, where each value is the number of same objects in the array.

# imperative style :-P

h = Hash.new(0)
[1, 3, 2, 3, 1, 3].each { |i| h[i]...

==== Replacement

# Method using returning can replaced
def foo
returning Hash.new do |h|
  h[:foo] = "bar"
end
end

# By method using tap  
def foo
Hash.new.tap do |h|
  h[:foo] = "bar"
end
end

For Rails 2.x use #save(false) for Rails 3.x use #save(:validate => false)

Regarding schmidt's post.

The following will not have the expected behavior:

<% Car.each do |c| %>
  <%= check_box_tag "car_ids[]", c.id, :id => "car_ids_#{c.id}" %>
<% end %>

But, if you put the "checked" option to false (or true), it will.

<% Car.each do |c| %>
  <%= check_...