Community contributions, tips, and corrections to the documentation. (1708 notes)
...to automatically define default scopes of inherited classes.
class Asset < ActiveRecord::Base
belongs_to :resource, :polymorphic => true before_save :set_asset_type
def set_asset_type self.asset_type = self.class.name end
def self.inherited(subclass) super...
Here is the formatted string for the W3CDTF datetime format (http://www.w3.org/TR/NOTE-datetime). It has a semicolon in the timezone part, therefore you cannot use '%z':
Time::DATE_FORMATS[:w3cdtf] = lambda { |time| time.strftime("%Y-%m-%dT%H:%M:%S#{time.formatted_offset}") }
If you have a string containing html and want to assert_select against it, as the doc states you have to pass in an element (HTML::Node) as the first argument. You can do something like this:
doc = HTML::Document.new('<p><span>example</span></p>')
assert_select doc.root, 'span'
If you need to escape brackets in a selector, this is the way to do it:
assert_select "input[type=hidden][name='user[role_ids][]']"
Reverse version of camelize is underscore
Accepts a single argument record_separator which is the character or string to chomp.
Why isn't this shown in the method def at the top?
Accepts a single argument sep_string
The undeprecated version of this function is here: ActionView::Helpers::PrototypeHelper#link_to_remote
You can check your current Rails environment using nice methods such as:
Rails.env.development?
Rails.env.test?
Rails.env.production?
Rails.env.your_custom_environment?
Sometimes you're gonna need this in controllers. Just put this in the controller:
include ActionView::Helpers::NumberHelper
The documentation says that the :find keywords "may include the :conditions, :joins, :include, :offset, :limit, and :readonly options". Note that this does not mean that only those options are supported. :sort also works like it should, for example.
Will this method get rid of existing data?
You can specifly :default option which is useful when the translation is not found. For example:
t(:this_translation_doesnt_exist, :default => 'Ooops!')
# => Ooops!
Or even any number of "fallbacks" - the first not nil is returned:
t(:missing, :default => [:missing_too, :existing, 'S...
May be helpful to know that this returns true if B is any ancestor of A, not just a direct one. As an example:
class Foo; end class Bar < Foo; end class Baz < Bar; end
Foo >= Bar #=> true Foo >= Baz #=> true
May be helpful to know that this returns true if B is any ancestor of A, not just a direct one. As an example:
class Foo; end class Bar < Foo; end class Baz < Bar; end
Foo > Bar #=> true Foo > Baz #=> true
May be helpful to know that this returns true if A is any descendant of B, not just a direct one. As an example:
class Foo; end class Bar < Foo; end class Baz < Bar; end
Bar <= Foo #=> true Baz <= Foo #=> true
May be helpful to know that this returns true if A is any descendant of B, not just a direct one. As an example:
class Foo; end class Bar < Foo; end class Baz < Bar; end
Bar < Foo #=> true Baz < Foo #=> true
If you want direct descendance try Class#superclass:
Bar.superclass == Foo #=> t...
Full detail: http://en.wikipedia.org/wiki/List_of_HTTP_status_codes