Ruby on Rails Tutorial 学习笔记-优快云博客

本文链接：https://blog.youkuaiyun.com/u010744827/article/details/84290535

第一章

1.在git中设置编辑器（用来编写比较多的评论）

$ git config --global core.editor "subl -w"

评论的时候，就不用git commit -m "XXX",忽略这里的-m,git会自动打开编辑器，在编辑器里面编辑评论内容

2.linux下删除文件夹

$ rm -rf app/controllers/

3.使用Git小技巧之一：在当前工作树中，没提交，想回到没做改动时候的版本（撤销本次修改）

$ git checkout -f
$ git status
# On branch master

4.创建新分支

$ git checkout -b modify-README
Switched to a new branch 'modify-README'
$ git branch
master
* modify-README

5.重命名命令：不算做是新文件

$ git mv README.rdoc README.md
$ sublime README.md（打开文件）

6.合并分支命令

$ git checkout master
Switched to branch 'master'
$ git merge modify-README
Updating 34f06b7..2c92bef

7.删除分支

$ git branch -d modify-README
Deleted branch modify-README (was 2c92bef).

8强制删除分支

$ git checkout -b topic-branch
$ <really screw up the branch>
$ git add .
$ git commit -a -m "Major screw up"
$ git checkout master
$ git branch -D topic-branch

9.之前项目中，比较常用的一种分支控制（合并时，--no-ff，可以保存历史信息，gitk命令可以看起来很漂亮）

$ git checkout develop
Switch to branch ‘develop’
$ git merge –no-ff myfeature
Updating ea1b82a..05e9557
(Summary of changes)
$ git branch -d myfeature
Deleted branch myfeature (was 05e9557).
$ git push origin develop

上述代码中的–no-ff标记会使合并永远创建一个新的commit对象，即使该合并能以fast-forward的方式进行。这么做可以避免丢失特性分支存在的历史信息，同时也能清晰的展现一组commit一起构成一个特性。

10.远程部署到heroku

先在heroku创建一个新项目

$ heroku create --stack cedar

(The --stack cedar argument arranges to use the latest and greatest version of Heroku, called the Celadon Cedar Stack.)

然后用git push到heroku

$ git push heroku master

第二章

1.现阶段项目使用的gemfile

source 'https://rubygems.org'

gem 'rails', '3.2.8'

group :development do
  gem 'sqlite3', '1.3.5'
end


# Gems used only for assets and not required
# in production environments by default.
group :assets do
  gem 'sass-rails',   '3.2.5'
  gem 'coffee-rails', '3.2.2'

  gem 'uglifier', '1.2.3'
end

gem 'jquery-rails', '2.0.2'

group :production do
  gem 'pg', '0.12.2'
end
 
    
 
   

其中，安装pg是为了部署在heroku上，因为heroku不支持sqlite3。然后

$ bundle install --without production

3.使用脚手架

$ rails generate scaffold User name:string email:string

4.数据迁移（使用gemfile中的rake）

$ bundle exec rake db:migrate

5.MVC in Rails

The browser issues a request for the /users URI.
Rails routes /users to the index action in the Users controller.
The index action asks the User model to retrieve all users (User.all).
The User model pulls all the users from the database.
The User model returns the list of users to the controller.
The controller captures the users in the @users variable, which is passed to the index view.
The view uses embedded Ruby to render the page as HTML.
The controller passes the HTML back to the browser.³

6RESTFul.

HTTP request	URI	Action	Purpose
`GET`	/users	`index`	page to list all users
`GET`	/users/1	`show`	page to show user with id `1`
`GET`	/users/new	`new`	page to make a new user
`POST`	/users	`create`	create a new user
`GET`	/users/1/edit	`edit`	page to edit user with id `1`
`PUT`	/users/1	`update`	update user with id `1`
`DELETE`	/users/1	`destroy`	delete user with id `1`

RESTful routes provided by the Users resource in Listing 2.2.

7.调用控制台与数据库交互

$ rails console
>> first_user = User.first
=> #<User id: 1, name: "Michael Hartl", email: "michael@example.org",
created_at: "2011-11-03 02:01:31", updated_at: "2011-11-03 02:01:31">
>> first_user.microposts

>> exit

这里，如果需要重载，键入：reload!

退出命令： Ctrl-d 或者 exit

第三章

1.新建一个忽略rails默认测试框架的新项目（我们使用RSpec来进行测试）

$ rails new sample_app --skip-test-unit

2.项目中使用到的gem清单

source 'https://rubygems.org'

gem 'rails', '3.2.8'

gem 'bootstrap-sass', '2.0.4'

gem 'bcrypt-ruby', '3.0.1'

gem 'faker', '1.0.1'

gem 'will_paginate', '3.0.3'

gem 'bootstrap-will_paginate', '0.0.6'

gem 'jquery-rails', '2.0.2'

group :development, :test do

gem 'sqlite3', '1.3.5'

gem 'rspec-rails', '2.11.0'

# gem 'guard-rspec', '0.5.5'

# gem 'guard-spork', '0.3.2'

# gem 'spork', '0.9.0'

end

# Gems used only for assets and not required

# in production environments by default.

group :assets do

gem 'sass-rails', '3.2.5'

gem 'coffee-rails', '3.2.2'

gem 'uglifier', '1.2.3'

end

group :test do

gem 'capybara', '1.1.2'

gem 'factory_girl_rails', '1.4.0'

gem 'cucumber-rails', '1.2.1', :require => false

gem 'database_cleaner', '0.7.0'

# gem 'launchy', '2.1.0'

# gem 'rb-fsevent', '0.9.1', :require => false

# gem 'growl', '1.0.3'

end

group :production do

gem 'pg', '0.12.2'

end

其中，pg是为了部署在heroku上面。

$ bundle install --without production

注意这里有一个细节，bundle install 后面的--without porduction是一个能够被记住的命令，以后bundle的时候，不用再敲这个可选命令，默认不再安装生产环境。

3.接着，我们配置Rails，让RSpec取代test:unit成为我们的测试工具

$ rails generate rspec:install

4.到这里，我们算是完成了项目的初始化，现在加入git

$ git init
$ git add .
$ git commit -m "Initial commit"

5.为了使readme这个文件更有帮助，而不是一大堆rails初始化之后的文字，我们将其变为markdown语言

# Ruby on Rails Tutorial: sample application

This is the sample application for
[*Ruby on Rails Tutorial: Learn Rails by Example*](http://railstutorial.org/)
by [Michael Hartl](http://michaelhartl.com/).

文件名称更改

$ git mv README.rdoc README.md
$ git commit -a -m "Improve the README"

6.现在在github上新建项目，然后提交git库代码上去。

7.顺便部署在heroku上呗

$ heroku create --stack cedar
$ git push heroku master

8.开始为项目加入静态页面

先确保我们安装了rspec，用来进行测试

$ rails generate rspec:install

然后，通过以下来创建一个控制器

$ rails generate controller StaticPages home help --no-test-framework

9.Rails中的“后悔药”。如果我们手一抖，打错了字，想更改某些东西，因为Rails g生成的不仅仅是某个主要文件，有很多附加的东西在rails g的时候也写入到rails项目当中了，所以，不能仅仅简单删除某个文件，下面有几个小方案：

  $ rails generate controller FooBars baz quux
  $ rails destroy  controller FooBars baz quux

这里不仅仅是针对controller，其他也适用。比如，第六章中，我们将要接触到的

 $ rails generate model Foo bar:string baz:integer

  $ rails destroy model Foo

10.欣赏以下routes.rb中，刚刚生成的 get "static_pages/home"

这句能够让URI与控制器连接起来，当用户请求/ static_pages/home这个URL的时候，路由器将调用控制器static_pages的help方法。这里也可以看到，路由/方法，这个规则。get，对应于HTTP的GET方法。

11.通过浏览器，访问服务器的HTTP传输协议，有四种方法 get , post , put , and delete

rails有对应。之前提到过。

12.项目中使用的是不同于TDD的测试方法-BDD行为驱动测试，主要的测试工具是集成测试和单元测试。

测试驱动项目的重要性不言而喻，虽然是一个书中的小例子，当作是做大项目的一个准则，在不是特别紧急的情况下，坚持测试驱动开发

13.集成测试，在RSpec的内容中就是我们所知的规格说明书测试，允许我们通过模拟用户在浏览器上的交互。

通过Capybara提供的自然语言语法，集成测试可以提供不需要手动用浏览器检测实现很多强大的功能。后面，我们也用另外一个工具，Cucumber来进行行为驱动测试。

第四章

('a'..'z').to_a.shuffle[0..7].join

Let’s build it up step-by-step:

>> ('a'..'z').to_a                     # An alphabet array
=> ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o",
"p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"]
>> ('a'..'z').to_a.shuffle             # Shuffle it.
=> ["c", "g", "l", "k", "h", "z", "s", "i", "n", "d", "y", "u", "t", "j", "q",
"b", "r", "o", "f", "e", "w", "v", "m", "a", "x", "p"]
>> ('a'..'z').to_a.shuffle[0..7]       # Pull out the first eight elements.
=> ["f", "w", "i", "a", "h", "p", "c", "x"]
>> ('a'..'z').to_a.shuffle[0..7].join  # Join them together to make one string.
=> "mznpybuj"

2.新旧hash符号对比

>> h1 = { :name => "Michael Hartl", :email => "michael@example.com" }
=> {:name=>"Michael Hartl", :email=>"michael@example.com"}
>> h2 = { name: "Michael Hartl", email: "michael@example.com" }
=> {:name=>"Michael Hartl", :email=>"michael@example.com"} 
>> h1 == h2
=> true

3.hash也响应each方法

>> flash = { success: "It worked!", error: "It failed." }
=> {:success=>"It worked!", :error=>"It failed."}
>> flash.each do |key, value|
?>   puts "Key #{key.inspect} has value #{value.inspect}"
>> end
Key :success has value "It worked!"
Key :error has value "It failed."

4.当hash作为参数的最后一个传递的时候，中括号是可以省略的

When hashes are the last argument in a function call, the curly braces are optional; these two lines are equivalent:

# Curly braces on final hash arguments are optional.
stylesheet_link_tag "application", { :media => "all" }
stylesheet_link_tag "application", :media => "all"

第五章

1. 用 match '/help' , to:'static_pages#help'，替换掉get "static_pages/help"

前者是定义了一种路由，到help方法，这时候会自动生成在控制器和view里用到的命名路由:help_path或者help_url,这两种

uri helper定义如下

about_path => '/about'
about_url  => 'http://localhost:3000/about'

第六章

1. rails c --sandbox

2.（做这里的时候出错，删除了本地文件，clone了github上的文件，遇到几个问题）：

一。 git clone到本地之后，运行bundle install提示我pg这个gem安装不成功，后来才发现，这是为生产环境所添加的gem,需要bundle install --without product这样的命令，一切都OK。

二。手动删除了本地public/index.html文件之后，发现提交时候一直出现delete项的提示，在github上看远程文件也还在，并没有更新远程代码。后来才发现，不能直接本地手动删除，需要git rm public/index.html这样删除，才能够提交到远程。

3.沙盒中练习对数据表的一些操作

$ rails console --sandbox
Loading development environment in sandbox
Any modifications you make will be rolled back on exit
>>

>> User.new
=> #<User id: nil, name: nil, email: nil, created_at: nil, updated_at: nil>

>> user = User.new(name: "Michael Hartl", email: "mhartl@example.com")
=> #<User id: nil, name: "Michael Hartl", email: "mhartl@example.com",
created_at: nil, updated_at: nil>

>> user.save
=> true

>> user
=> #<User id: 1, name: "Michael Hartl", email: "mhartl@example.com",
created_at: "2011-12-05 00:57:46", updated_at: "2011-12-05 00:57:46">

>> user.name
=> "Michael Hartl"
>> user.email
=> "mhartl@example.com"
>> user.updated_at
=> Tue, 05 Dec 2011 00:57:46 UTC +00:00

>> User.create(name: "A Nother", email: "another@example.org")
#<User id: 2, name: "A Nother", email: "another@example.org", created_at:
"2011-12-05 01:05:24", updated_at: "2011-12-05 01:05:24">
>> foo = User.create(name: "Foo", email: "foo@bar.com")
#<User id: 3, name: "Foo", email: "foo@bar.com", created_at: "2011-12-05
01:05:42", updated_at: "2011-12-05 01:05:42">

>> foo.destroy
=> #<User id: 3, name: "Foo", email: "foo@bar.com", created_at: "2011-12-05
01:05:42", updated_at: "2011-12-05 01:05:42">

>> foo
=> #<User id: 3, name: "Foo", email: "foo@bar.com", created_at: "2011-12-05
01:05:42", updated_at: "2011-12-05 01:05:42">

>> User.find(1)
=> #<User id: 1, name: "Michael Hartl", email: "mhartl@example.com",
created_at: "2011-12-05 00:57:46", updated_at: "2011-12-05 00:57:46">

>> User.find(3)
ActiveRecord::RecordNotFound: Couldn't find User with ID=3

>> User.find_by_email("mhartl@example.com")
=> #<User id: 1, name: "Michael Hartl", email: "mhartl@example.com",
created_at: "2011-12-05 00:57:46", updated_at: "2011-12-05 00:57:46">

>> User.first
=> #<User id: 1, name: "Michael Hartl", email: "mhartl@example.com",
created_at: "2011-12-05 00:57:46", updated_at: "2011-12-05 00:57:46"

一些更新练习

>> user           # Just a reminder about our user's attributes
=> #<User id: 1, name: "Michael Hartl", email: "mhartl@example.com",
created_at: "2011-12-05 00:57:46", updated_at: "2011-12-05 00:57:46">
>> user.email = "mhartl@example.net"
=> "mhartl@example.net"
>> user.save
=> true

>> user.email
=> "mhartl@example.net"
>> user.email = "foo@bar.com"
=> "foo@bar.com"
>> user.reload.email
=> "mhartl@example.net"

>> user.created_at
=> "2011-12-05 00:57:46"
>> user.updated_at
=> "2011-12-05 01:37:32"

6.2数据验证

验证存在

class User < ActiveRecord::Base 
  attr_accessible :name, :email

  validates :name, presence: true
end

可以通过控制台的沙盒查看

$ rails console --sandbox
>> user = User.new(name: "", email: "mhartl@example.com")
>> user.save
=> false
>> user.valid?
=> false

这里，我们还有一个函数，可以查看完整的出错信息

>> user.errors.full_messages
=> ["Name can't be blank"]

验证长度

class User < ActiveRecord::Base 
  attr_accessible :name, :email

  validates :name,  presence: true, length: { maximum: 50 }
  validates :email, presence: true
end

验证邮箱

class User < ActiveRecord::Base
  attr_accessible :name, :email

  validates :name,  presence: true, length: { maximum: 50 }
  VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
  validates :email, presence: true, format: { with: VALID_EMAIL_REGEX }
end

练习正则表达式：

http://www.rubular.com/

常用的正则表达式

Expression	Meaning
`/\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i`	full regex
`/`	start of regex
`\A`	match start of a string
`[\w+\-.]+`	at least one word character, plus, hyphen, or dot
`@`	literal “at sign”
`[a-z\d\-.]+`	at least one letter, digit, hyphen, or dot
`\.`	literal dot
`[a-z]+`	at least one letter
`\z`	match end of a string
`/`	end of regex
`i`	case insensitive

验证邮箱，并且是大小写不敏感的

class User < ActiveRecord::Base
  .
  .
  .
  validates :email, presence: true, format: { with: VALID_EMAIL_REGEX },
                    uniqueness: { case_sensitive: false }
end
 
    
 
   

但是，通过这样的验证，就能证明我们用户的邮箱保证不重叠么？不是这样的，设想，如果John提交了两次，这两次在极其短暂的时间，那么就会通过这两次验证，数据库中就会存在两个一样的email。在大量访问的情况下，这种情况就更普遍了，所以，为了避免这种情况，我们需要在数据库层级的email列创建一个索引，然后要求索引是惟一的。

这时候，我们需要添加一个索引

$ rails generate migration add_index_to_users_email

与产生users的时候不同，我们需要手动添加内容

class AddIndexToUsersEmail < ActiveRecord::Migration
  def change
    add_index :users, :email, unique: true
  end
end

然后数据迁移

bundle exec rake db:migrate

update-to Listing 6.22.

问题，数据库迁移没成功，以前遇到过这种问题，明晚重新启动再看看。

果然，重启之后，成功迁移。。。

Ruby on Rails Tutorial 学习笔记

6.3 Adding a secure password