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Пример рефакторинга с использованием транзакций

Опять рассмотрим tasks#create экшен.

В экшене 3 разных логики, которые выполняются последовательно:

1. валидация данных - необходимый шаг;
2. сохраниение таска - необходимый шаг, если какая-то ошибка, необходимо возвращать failed значение;
3. отправка нотификаций - мы не хотим, что бы наша транзакия не выполнялась, если отправка нотификации не выполнится;

Поэтому напишем нашу транзакцию. Так же мы будем использовать Either монаду для возвращения статуса шага транзакции. Right для успешного, Left - не успешного:

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// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

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source 'https://rubygems.org'

BUNDLE_RAILS_VERSION = '~> 4.2.4'

# Rails
gem 'railties',      BUNDLE_RAILS_VERSION
gem 'activesupport', BUNDLE_RAILS_VERSION
gem 'actionpack',    BUNDLE_RAILS_VERSION
gem 'actionmailer',  BUNDLE_RAILS_VERSION
gem 'activejob',     BUNDLE_RAILS_VERSION

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module AuthHelper
  def http_login
    user = 'username'
    pw = 'password'
    request.env['HTTP_AUTHORIZATION'] = ActionController::HttpAuthentication::Basic.encode_credentials(user,pw)
  end
end

module AuthRequestHelper
  #

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class PagesController < ApplicationController
  before_filter :login_required, :except => [ :show ]
  
  # GET /pages
  # GET /pages.xml
  def index
    @pages = Page.find(:all)

    respond_to do |format|
      format.html # index.html.erb

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Render and Redirect

The normal controller/view flow is to display a view template corresponding to the current controller action, but sometimes we want to change that. We use render in a controller when we want to respond within the current request, and redirect_to when we want to spawn a new request.

Render

The render method is very overloaded in Rails. Most developers encounter it within the view template, using render :partial => 'form' or render @post.comments, but here we'll focus on usage within the controller.

:action

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#Model 

@user.should have(1).error_on(:username) # Checks whether there is an error in username 
@user.errors[:username].should include("can't be blank")  # check for the error message 

#Rendering
response.should render_template(:index)

#Redirecting 
response.should redirect_to(movies_path)

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In Rails 3

NOTE: This post now lives (and kept up to date) on my blog: http://hakunin.com/rails3-load-paths

If you add a dir directly under app/

Do nothing. All files in this dir are eager loaded in production and lazy loaded in development by default.

If you add a dir under app/something/

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# Permissions cheatsheet

`chmod [a]bcd`

* bit a — sticky:1/setgid:2/setuid:4 (optional, default: 0)
* bit b — owner    | x:1/w:2/r:4 - xw:3/xr:5/wr:6/xwr:7
* bit c — group    | x:1/w:2/r:4 - xw:3/xr:5/wr:6/xwr:7
* bit d — everyone | x:1/w:2/r:4 - xw:3/xr:5/wr:6/xwr:7

note: only file/dir owner can chmod it

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=Navigating=
    visit('/projects')
    visit(post_comments_path(post))

=Clicking links and buttons=
    click_link('id-of-link')
    click_link('Link Text')
    click_button('Save')
    click('Link Text') # Click either a link or a button
    click('Button Value')