Rails Study(I)Getting Started with Rails

Rails Study(I)Getting Started with Rails

1. MVC Architecture
1.1. Models
One table in my database will correspond to one model in my application.
The bulk of my application's bussiness logic will be concentrated in the models.

1.2. Views
Views are often HTML files with embedded Ruby code that perform tasks related solely to the presentation of the data.

1.3. Controllers
Controllers provide the "glue" between models and views.

2. The Components of Rails
Action Pack
Action Controller
Action Dispatch
Action View
Action Mailer
Action Model
Action Record
Action Resource
Active Support
Railties

2.1 Action Pack
2.1.1 Action Controller
Action Controller processes incoming requests to a Rails application, extracts parameters, and dispatches them to the intended
action.

Services provided by Action Controller include session management, template rendering, and redirect management.

2.1.2 Action view
Action view can create both HTML and XML output. Action View manages rendering templates, including nested and partial
templates, and includes built-in AJAX support.

2.1.3 Action Dispatch
2.1.4 Action Mailer
A framework for building e-mail services.

2.1.5 Action Model
Action Model -----> Business Logic -----> ORM

2.1.6 Action Record
CRUD functionality

2.1.7 Action Resource
2.1.8 Action Support

2.2 REST

3. Creating a New Rails Project
Creating a Blog Application
>rails new railsexample

or I can create a rails project in eclipse.

type >rails -h in eclipse command console for more information.

File Purpose
Gemfile This file allows you to specify what gem dependencies are needed for your Rails application
Readme
Rakefile This file contains batch jobs that can be run from the terminal
config.ru Rack configuration for Rack based servers used to start the application.

Folder Purpose
app Contains the controllers, models, and views for your application. You'll focus on this folder for the remainder of this
guide.
config Configure your application's runtime rules, routes, database, and more.
db Shows your current database schema
doc
lib Extended modules for my application
log
public This is where you put your images, javasript, stylesheets(CSS), and other static files.
script Contains the rails script that starts your app and can contain other scripts you use to deploy or run applications
test
tmp
vendor A place for all third-party code. In a typical Rails application, this includes Ruby Gems, the Rails source code (if you install
it into your project) and plugins containing additional prepackaged functionality.

3.1 Installing the Required Gems
>bundle install

3.2 Configuring a Database
config/database.yml

3.2.1 Configuring an SQLite3 Database
development:
adapter: sqlite3
database: db/development.sqlite3
pool: 5
timeout: 5000

3.2.2 Configuring a MySQL Database
development:
adapter: mysql2
encoding: utf8
database: example_development
pool: 5
username: root
password:
socket: /tmp/mysql.sock

3.3 Creating the Database
>rake db:create

error message:
rake aborted!
uninitialized constant Rake::DSL
d:/tool/Ruby192/lib/ruby/1.9.1/rake.rb:2482:in `const_missing'
d:/tool/Ruby192/lib/ruby/gems/1.9.1/gems/rake-0.9.2/lib/rake/tasklib.rb:8:in `<class:TaskLib>'

Solutions:
Change the Rakefile

require File.expand_path('../config/application', __FILE__)
require 'rake/dsl_definition'

module ::Railsexample
class Application
include Rake::DSL
end
end

module ::RakeFileUtils
extend Rake::FileUtilsExt
end

Railsexample::Application.load_tasks

>bundle update
>rake db:create

error message:
uninitialized constant Mysql2

solution:
>gem install mysql2
Fetching: mysql2-0.3.6.gem (100%)

error message:
ERROR: Error installing mysql2:
The 'mysql2' native gem requires installed build tools.

Please update your PATH to include build tools or download the DevKit
from 'http://rubyinstaller.org/downloads' and follow the instructions
at 'http://github.com/oneclick/rubyinstaller/wiki/Development-Kit'

solution:
Download the file DevKit-tdm-32-4.5.2-20110712-1620-sfx.exe in 7zip format from that URL
Create a directory devkit and unzip the file there with 7zip software.
Copy the directory devkit to d:/tool/devkit
>cd d:/tool/devkit
>ruby dk.rb init
This step will list the installation of ruby and generate a file named config.yml
>ruby dk.rb install

After all the steps, do install mysql2 again.
>gem install mysql2
No, but the problem is still there.

>gem install mysql2 -v 0.2.6 --platform x86-mingw32

change Gemfile and add one line
gem 'mysql2', '0.2.6'

>rake db:create

error message:
The program can't start because LIBMYSQL.dll is missing from your
computer. Try reinstalling the program to fix this problem.

solution:
Copy file D:\ProgramFiles\MySQL\MySQL Server 5.5\lib\libmysql.dll to directory D:\tool\Ruby192\bin

try again. >rake db:create

error message:
193: %1 is not a valid Win32 application. - d:/tool/Ruby192/lib/ruby/gems/1.9.1/gems/mysql2-0.2.6-x
86-mingw32/lib/mysql2/1.9/mysql2.so

try other ways
>gem install mysql2 -v 0.2.6 -- --with-mysql-dir="D:\ProgramFiles\MySQL\MySQL Server 5.5"

try other ways
>gem install mysql2 -- --with-mysql-lib="D:\ProgramFiles\MySQL\MySQL Server 5.5\lib" --with-mysql-include="D:\ProgramFiles\MySQL\MySQL Server 5.5\include" --with-mysql-dir="D:\ProgramFiles\MySQL\MySQL Server 5.5"

try other ways
Gemfile
gem 'mysql', '2.8.1'

adapter mysql

>bundle install
>rake db:create
>gem list -d mysql
Same problem.

Finally I download the file from http://instantrails.rubyforge.org/svn/trunk/InstantRails-win/InstantRails/mysql/bin/libmySQL.dll
and put this file to ruby_home/bin.
>rake db:create
It works.

references:
http://guides.rubyonrails.org/
https://github.com/oneclick/rubyinstaller/wiki/Development-Kit
http://www.iteye.com/topic/1001758