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January 25, 2010
2 thanks

custom uniq method

Build hash from elements of your Array using attribute as key and the element as value and return values of Hash:

Hash[*ary.map {|obj| [obj.name, obj]}.flatten].values
January 22, 2010
1 thank

Interesting usage for polymorphic asset model :)

…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
    subclass.send(:default_scope, :conditions => "asset_type='#{subclass.name}'")
  end
end
January 21, 2010
3 thanks

W3CDTF Format

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}") }
January 20, 2010
4 thanks

Using html text instead of default response

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'
January 20, 2010
2 thanks

Escape brackets in selector

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][]']"
January 20, 2010
3 thanks
January 19, 2010
2 thanks

Argument Accepted

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?

January 19, 2010
2 thanks

Argument Accepted

Accepts a single argument sep_string

January 18, 2010
1 thank

Undeprecated version

The undeprecated version of this function is here: ActionView::Helpers::PrototypeHelper#link_to_remote

January 16, 2010 - (>= v2.2.1)
8 thanks

Pretty way to test for current environment

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?
January 15, 2010
3 thanks

Use this in controllers

Sometimes you’re gonna need this in controllers. Just put this in the controller:

include ActionView::Helpers::NumberHelper
January 14, 2010
0 thanks

:find takes more keys than written

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.

January 14, 2010
1 thank

Will this method get rid of existing data?

Will this method get rid of existing data?

January 11, 2010 - (>= v2.2.1)
2 thanks

Default fallback

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, 'Sad panda'])
# => :existing translation

Good introduction to Rails I18n is http://guides.rubyonrails.org/i18n.html

January 11, 2010
2 thanks
January 11, 2010
0 thanks

Includes all ancestors

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
January 11, 2010
0 thanks

Includes all ancestors

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
January 11, 2010
0 thanks

Includes descendants

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
January 11, 2010
0 thanks

Includes descendants

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 #=> true
Baz.superclass == Foo #=> false
January 8, 2010
1 thank

Status Codes

Full detail: http://en.wikipedia.org/wiki/List_of_HTTP_status_codes

  • 100 - Continue

  • 101 - Switching Protocols

  • 200 - OK

  • 201 - Created

  • 202 - Accepted

  • 203 - Non-Authoritative Information

  • 204 - No Content

  • 205 - Reset Content

  • 206 - Partial Content

  • 300 - Multiple Choices

  • 301 - Moved Permanently

  • 302 - Found

  • 303 - See Other

  • 304 - Not Modified

  • 305 - Use Proxy

  • 306 - No Longer Used

  • 307 - Temporary Redirect

  • 400 - Bad Request

  • 401 - Not Authorised

  • 402 - Payment Required

  • 403 - Forbidden

  • 404 - Not Found

  • 405 - Method Not Allowed

  • 406 - Not Acceptable

  • 407 - Proxy Authentication Required

  • 408 - Request Timeout

  • 409 - Conflict

  • 410 - Gone

  • 411 - Length Required

  • 412 - Precondition Failed

  • 413 - Request Entity Too Large

  • 414 - Request URI Too Long

  • 415 - Unsupported Media Type

  • 416 - Requested Range Not Satisfiable

  • 417 - Expectation Failed

  • 500 - Internal Server Error

  • 501 - Not Implemented

  • 502 - Bad Gateway

  • 503 - Service Unavailable

  • 504 - Gateway Timeout

  • 505 - HTTP Version Not Supported

January 6, 2010
6 thanks

Doesn't return nil if the object you try from isn't nil.

Note that this doesn’t prevent a NoMethodError if you attempt to call a method that doesn’t exist on a valid object.

a = Article.new

a.try(:author) #=> #<Author ...>

nil.try(:doesnt_exist) #=> nil

a.try(:doesnt_exist) #=> NoMethodError: undefined method `doesnt_exist' for #<Article:0x106c7d5d8>

This is on Ruby 1.8.7 patchlevel 174

January 6, 2010
1 thank

Alternative:

without using at

[:a, :b, :c].try(:[], 1)
December 31, 2009
2 thanks

Replacing with "\" and match — a simple solution

A somewhat different approach to the same problem:

v.gsub(/(?=\W)/, '\\') #=> Foo\ Bar\!

But from what you are trying to achieve I suspect you might be interested in Regexp.escape method :)

December 28, 2009
4 thanks

Attribute names are Strings, not Symbols

Another possible gotcha – the returned hash keys are of type String, not Symbol:

user.attributes["login"] # => "joe"
user.attributes[:login] # => nil
December 23, 2009 - (<= v2.3.2)
0 thanks

Compare dates

You can check a date resides between two dates.

Date.today.between?(Date.yesterday, Date.tomorrow)

will return true

Date.yesterday.between?(Date.today, Date.tomorrow)

will return false

December 21, 2009
0 thanks

expire_page outside controller and sweepers

If you want to expire cached pages from scripts or console just use class-method expire_page. But don’t forget about difference between instance and class method. In class-method you pass page url, not a hash of action/controller:

ActionController::Base.expire_page your_page_url
December 21, 2009 - (>= v2.0.0)
0 thanks

Expire cache from console or whatever...

I know only one possible method:

ApplicationController.new.expire_fragment(:your_fragment)

December 18, 2009
4 thanks

Version Ranges

To specify a version range, use array syntax like this:

config.gem 'paperclip', :version => ['>= 2.3.1.1', '< 3.0']

The example will, of course, match any version 2.3.1.1 or newer up until (not including) 3.0 or later.

December 16, 2009
0 thanks

path

send_file always uses the absolute path /www/somewebsite/public/downloads/file