Recent notes

You can add if: :query_method and unless: :query_method

You can make the callback conditional:

before_save :before_method, if: :needs_before_method?

private

def needs_before_method?
   false
end

def before_method
  # .. 
end

How to set request parameters (rails 3.2)

In Rails 3.2, this seems to work to create a TestRequest based on a certain url:

ActionController::TestRequest.new( Rack::MockRequest.env_for("http://something.tld/foo?one=two&three=four") )    

Example Regex format matching

for phone and email

validates_format_of :phone, with: /\A(\d{10}|\(?\d{3}\)?[-. ]\d{3}[-.]\d{4})\z/
validates_format_of :email, with: /\A[\w]([^@\s,;]+)@(([\w-]+\.)+(com|edu|org|net|gov|mil|biz|info))\z/i

another way

Perhaps a more efficient way:

def create
  @post = Post.new(post_params)
  if @post.save
    redirect_to @post, notice: "The post #{@post.title} was added to the system."
  else
    render action: 'new'
  end
end

where post_params is:

private

def post_params
  params.require(:post).permit(..attributes to permit..)
end

Security

In regards to @aamer’s comment on including the password salt this is a bad idea. `ActiveSupport::MessageVerifier` is NOT encrypted so:

verifier = ActiveSupport::MessageVerifier.new('secret')
id = 'id'
salt = 'salt'
verifier.generate("#{id}-#{salt}") # "BAhJIgxpZC1zYWx0BjoGRVQ=--c880254708d18ce4a686bcd96a25cf0d2117e1e0"

Base64.decode64(token.split("--").first) # "...id-salt..."

Note how the salt and id are both exposed! Instead a different token (reset_passowrd_token) should be used.

Passing an array of keys to exclude.

Use the “*” before passing the array in. For example:

PARAMS_TO_SCRUB = [ :created_at, :updated, :id, :format ]

params.except!( *PARAMS_TO_SCRUB )

First example's output is incorrect

Everything except the initially html_safe input should be escaped in the output.

The output of the first example should be:

# => "<p>foo</p>&lt;br /&gt;&lt;p&gt;bar&lt;/p&gt;"

Does not symbolize hashes in nested arrays

If you have a nested structure containing arrays of hashes, you still need to do that on your own, eg.

module SymbolizeHelper
  def symbolize_recursive(hash)
    {}.tap do |h|
      hash.each { |key, value| h[key.to_sym] = map_value(value) }
    end
  end

  def map_value(thing)
    case thing
    when Hash
      symbolize_recursive(thing)
    when Array
      thing.map { |v| map_value(v) }
    else
      thing
    end
  end
end

Or, if you want to get really fancy with Ruby refinements (YMMV), one could do

module SymbolizeHelper
  extend self

  def symbolize_recursive(hash)
    {}.tap do |h|
      hash.each { |key, value| h[key.to_sym] = transform(value) }
    end
  end

  private

  def transform(thing)
    case thing
    when Hash; symbolize_recursive(thing)
    when Array; thing.map { |v| transform(v) }
    else; thing
    end
  end

  refine Hash do
    def deep_symbolize_keys
      SymbolizeHelper.symbolize_recursive(self)
    end
  end
end

And later say

using SymbolizeHelper # augmented Hash#deep_symbolize_keys is now available

Does not work with ActionController::BadRequest

This method will not work with ActionController::BadRequest

Compatible with old docs

Library is moved, so old library documentation is compatible http://apidock.com/rails/v3.0.9/ActionController/Streaming/send_file

Sample

Here is a sample usage of its,

Code example

describe '#rate_for_date' do
  context 'with date with in the range' do
    subject do 
      FactoryGirl.build(:allocated_room_rate, 
          start_date: Time.zone.now, 
          end_date: 2.day.from_now, 
          price: 1000)
    end
    its(:daily_rate) { should == 500 }
  end
end

You could pass a range as the choices parameter

select :object, :method, (1..5)

Requires inheritance of ActionController::Metal

The example code will not work unless class inherits from ActionController::Metal (to get functioning controller) or at least AbstractController:Base.

link_to_if when URL helpers will throw an exception when condition fails

You can use an array to build a URL instead of a URL helper (e.g. edit_admin_user_path(event.user), which would fail when an event has no user:

link_to_if event.user, event.user_name, [:edit, :admin, event.user]

Sometimes, you need the "Oxford comma"

Re: Gramatical error

http://imgur.com/fycHx

We invited the strippers, JFK, and Stalin.

versus the appositive phrase:

We invited the strippers, JFK and Stalin.

(Really, you need to see the comic to appreciate the difference.)

Grammatical error

Hi - not sure where I would submit this so just putting here. My apologies if not in the right place.

default: “, and ” - this is grammatically wrong. There should be no comma with the last and.

Example:

[‘one’, ‘two’, ‘three’].to_sentence

should give: “one, two and three”

There is no ‘ .… , and ’ which is considered grammatically incorrect I feel. The ‘and’ does it’s job in the English language quite well by joining the two words it’s in between.

Thank you.

Update for Rails 4

In the example

select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, { include_blank: true })

It can be updated to

select("post", "person_id", Person.pluck(:name, :id), { include_blank: true })

Right Partitioning Filename extension

1.9.3p392 :013 > x = “picture.2.jpg”

=> "picture.2.jpg" 

1.9.3p392 :015 > x.rpartition(‘.’)

=> ["picture.2", ".", "jpg"] 

gives a parameter

As a note, you can use it like this:

after_save {|instance|

}

it will pass in the instance being saved.

form_for with :path route

Similar to danwich’s note, if you specify a route using the :path option

resource :posts, path: 'articles'

then the form_for tag must specify the :url option

form_for(@post), url: post_path(@post)

missing :through option

So the way to do the equivalent of a has_many :through is to use has_one :through, with the expected names.

so using the other example we could do

eg

class Person < ActiveRecord::Base
  belongs_to :team
  ...
end
class Task < ActiveRecord::Base
  belongs_to :person
  has_one :team, :through => :person
end

Article

Here is artice about this method http://blog.envylabs.com/post/75521798481/token-based-authentication-in-rails

Rendering JSONP

If you provide the :callback option with a nil value, then the default JSON object will be returned. As such, this makes creating JSONP response from the render syntax very easy in your controllers, like so:

render json: @object, callback: params[:jsoncallback]

Undocumented pile of ruby

> If you’d like to read someone’s RSS feed with your Ruby code, you’ve come to the right place

No, you’ve definitely come to wrong place. RSS is one of the worst documented libraries I’ve ever seen for Ruby. It’s as confusing and misleading as it can get.

Docs from activerecord-4.0.2/lib/active_record/relation/query_methods.rb:175

See http://apidock.com/rails/v4.0.2/ActiveRecord/QueryMethods/select

Alternative to :symbol

You can also pass string as an alternative to :symbol

k = Klass.new

k.send “hello”, “gentle”, “readers” #=> “Hello gentle readers”

Symbols more performant than strings

>> options_from_collection_for_select(@posts, :slug, :title, params[:slug])

Consider using symbols for performance, otherwise it will generate a string each time instead of a symbol which will reference the same object.

re: question?

Nope. Read it again:

> This generates a sequence of self.size n-element arrays

If any of the arguments are longer than the receiver, the elements beyond the receiver’s length are ignored

Storing array values

I tried to add a array value using hidden_field_tag and access it in jquery. It just returns the flattened version of array. eg:(If i try to store [1,[1,2,3]] in hidden_field_tag , in jquery iam just getting ‘1 1 2 3’) but if i use input field with type=hidden iam getting the correct value. Why is that?

using hash as order

order can be specified as a hash, e.g.:

order(id: :desc)

This will prevent “ambiguous column” errors when the order is used with joins or includes.