rails跑通第一个demo

rails -h 查看帮助

Usage:
  rails new APP_PATH [options]

Options:
  -r, [--ruby=PATH]              # Path to the Ruby binary of your choice
                                 # Default: D:/Rails/Ruby1.9.3/bin/ruby.exe
  -b, [--builder=BUILDER]        # Path to a application builder (can be a files
ystem path or URL)
  -m, [--template=TEMPLATE]      # Path to an application template (can be a fil
esystem path or URL)
      [--skip-gemfile]           # Don't create a Gemfile
      [--skip-bundle]            # Don't run bundle install
  -G, [--skip-git]               # Skip Git ignores and keeps
  -O, [--skip-active-record]     # Skip Active Record files
  -S, [--skip-sprockets]         # Skip Sprockets files
  -d, [--database=DATABASE]      # Preconfigure for selected database (options:
mysql/oracle/postgresql/sqlite3/frontbase/ibm_db/sqlserver/jdbcmysql/jdbcsqlite3
/jdbcpostgresql/jdbc)
                                 # Default: sqlite3
  -j, [--javascript=JAVASCRIPT]  # Preconfigure for selected JavaScript library
                                 # Default: jquery
  -J, [--skip-javascript]        # Skip JavaScript files
      [--dev]                    # Setup the application with Gemfile pointing t
o your Rails checkout
      [--edge]                   # Setup the application with Gemfile pointing t
o Rails repository
  -T, [--skip-test-unit]         # Skip Test::Unit files
      [--old-style-hash]         # Force using old style hash (:foo => 'bar') on
 Ruby >= 1.9

Runtime options:
  -f, [--force]    # Overwrite files that already exist
  -p, [--pretend]  # Run but do not make any changes
  -q, [--quiet]    # Supress status output
  -s, [--skip]     # Skip files that already exist

Rails options:
  -h, [--help]     # Show this help message and quit
  -v, [--version]  # Show Rails version number and quit

Description:
    The 'rails new' command creates a new Rails application with a default
    directory structure and configuration at the path you specify.

    You can specify extra command-line arguments to be used every time
    'rails new' runs in the .railsrc configuration file in your home directory.

    Note that the arguments specified in the .railsrc file don't affect the
    defaults values shown above in this help message.

Example:
    rails new ~/Code/Ruby/weblog

    This generates a skeletal Rails installation in ~/Code/Ruby/weblog.
    See the README in the newly created application to get going.

不要说没有文档，文档都在指令里面
rails --help

The most common rails commands are:
 generate    Generate new code (short-cut alias: "g")
 console     Start the Rails console (short-cut alias: "c")
 server      Start the Rails server (short-cut alias: "s")
 dbconsole   Start a console for the database specified in config/database.yml
             (short-cut alias: "db")
 new         Create a new Rails application. "rails new my_app" creates a
             new application called MyApp in "./my_app"

In addition to those, there are:
 application  Generate the Rails application code
 destroy      Undo code generated with "generate" (short-cut alias: "d")
 benchmarker  See how fast a piece of code runs
 profiler     Get profile information from a piece of code
 plugin       Install a plugin
 runner       Run a piece of code in the application environment (short-cut alia
s: "r")

All commands can be run with -h (or --help) for more information.

还有些帮助文档在项目当中
README.rdoc

这里的内容更详细

== Welcome to Rails

Rails is a web-application framework that includes everything needed to create
database-backed web applications according to the Model-View-Control pattern.

This pattern splits the view (also called the presentation) into "dumb"
templates that are primarily responsible for inserting pre-built data in between
HTML tags. The model contains the "smart" domain objects (such as Account,
Product, Person, Post) that holds all the business logic and knows how to
persist themselves to a database. The controller handles the incoming requests
(such as Save New Account, Update Product, Show Post) by manipulating the model
and directing data to the view.

In Rails, the model is handled by what's called an object-relational mapping
layer entitled Active Record. This layer allows you to present the data from
database rows as objects and embellish these data objects with business logic
methods. You can read more about Active Record in
link:files/vendor/rails/activerecord/README.html.

The controller and view are handled by the Action Pack, which handles both
layers by its two parts: Action View and Action Controller. These two layers
are bundled in a single package due to their heavy interdependence. This is
unlike the relationship between the Active Record and Action Pack that is much
more separate. Each of these packages can be used independently outside of
Rails. You can read more about Action Pack in
link:files/vendor/rails/actionpack/README.html.

== Getting Started

. At the command prompt, create a new Rails application:
       <tt>rails new myapp</tt> (where <tt>myapp</tt> is the application name)

. Change directory to <tt>myapp</tt> and start the web server:
       <tt>cd myapp; rails server</tt> (run with --help for options)

. Go to http://localhost:3000/ and you'll see:
       "Welcome aboard: You're riding Ruby on Rails!"

. Follow the guidelines to start developing your application. You can find
the following resources handy:

* The Getting Started Guide: http://guides.rubyonrails.org/getting_started.html
* Ruby on Rails Tutorial Book: http://www.railstutorial.org/

== Debugging Rails

Sometimes your application goes wrong. Fortunately there are a lot of tools that
will help you debug it and get it back on the rails.

First area to check is the application log files. Have "tail -f" commands
running on the server.log and development.log. Rails will automatically display
debugging and runtime information to these files. Debugging info will also be
shown in the browser on requests from 127.0.0.1.

You can also log your own messages directly into the log file from your code
using the Ruby logger class from inside your controllers. Example:

  class WeblogController < ActionController::Base
    def destroy
      @weblog = Weblog.find(params[:id])
      @weblog.destroy
      logger.info("#{Time.now} Destroyed Weblog ID ##{@weblog.id}!")
    end
  end

The result will be a message in your log file along the lines of:

  Mon Oct  :: +  Destroyed Weblog ID #!

More information on how to use the logger is at http://www.ruby-doc.org/core/

Also, Ruby documentation can be found at http://www.ruby-lang.org/. There are
several books available online as well:

* Programming Ruby: http://www.ruby-doc.org/docs/ProgrammingRuby/ (Pickaxe)
* Learn to Program: http://pine.fm/LearnToProgram/ (a beginners guide)

These two books will bring you up to speed on the Ruby language and also on
programming in general.

== Debugger

Debugger support is available through the debugger command when you start your
Mongrel or WEBrick server with --debugger. This means that you can break out of
execution at any point in the code, investigate and change the model, and then,
resume execution! You need to install ruby-debug to run the server in debugging
mode. With gems, use <tt>sudo gem install ruby-debug</tt>. Example:

  class WeblogController < ActionController::Base
    def index
      @posts = Post.all
      debugger
    end
  end

So the controller will accept the action, run the first line, then present you
with a IRB prompt in the server window. Here you can do things like:

  >> @posts.inspect
  => "[#<Post:0x14a6be8
          @attributes={"title"=>nil, "body"=>nil, "id"=>""}>,
       #<Post:0x14a6620
          @attributes={"title"=>"Rails", "body"=>"Only ten..", "id"=>""}>]"
  >> @posts.first.title = "hello from a debugger"
  => "hello from a debugger"

...and even better, you can examine how your runtime objects actually work:

  >> f = @posts.first
  => #<Post:0x13630c4 @attributes={"title"=>nil, "body"=>nil, "id"=>""}>
  >> f.
  Display all  possibilities? (y or n)

Finally, when you're ready to resume execution, you can enter "cont".

== Console

The console is a Ruby shell, which allows you to interact with your
application's domain model. Here you'll have all parts of the application
configured, just like it is when the application is running. You can inspect
domain models, change values, and save to the database. Starting the script
without arguments will launch it in the development environment.

To start the console, run <tt>rails console</tt> from the application
directory.

Options:

* Passing the <tt>-s, --sandbox</tt> argument will rollback any modifications
  made to the database.
* Passing an environment name as an argument will load the corresponding
  environment. Example: <tt>rails console production</tt>.

To reload your controllers and models after launching the console run
<tt>reload!</tt>

More information about irb can be found at:
link:http://www.rubycentral.org/pickaxe/irb.html

== dbconsole

You can go to the command line of your database directly through <tt>rails
dbconsole</tt>. You would be connected to the database with the credentials
defined in database.yml. Starting the script without arguments will connect you
to the development database. Passing an argument will connect you to a different
database, like <tt>rails dbconsole production</tt>. Currently works for MySQL,
PostgreSQL and SQLite .

== Description of Contents

The default directory structure of a generated Ruby on Rails application:

  |-- app
  |   |-- assets
  |       |-- images
  |       |-- javascripts
  |       `-- stylesheets
  |   |-- controllers
  |   |-- helpers
  |   |-- mailers
  |   |-- models
  |   `-- views
  |       `-- layouts
  |-- config
  |   |-- environments
  |   |-- initializers
  |   `-- locales
  |-- db
  |-- doc
  |-- lib
  |   `-- tasks
  |-- log
  |-- public
  |-- script
  |-- test
  |   |-- fixtures
  |   |-- functional
  |   |-- integration
  |   |-- performance
  |   `-- unit
  |-- tmp
  |   |-- cache
  |   |-- pids
  |   |-- sessions
  |   `-- sockets
  `-- vendor
      |-- assets
          `-- stylesheets
      `-- plugins

app
  Holds all the code that's specific to this particular application.

app/assets
  Contains subdirectories for images, stylesheets, and JavaScript files.

app/controllers
  Holds controllers that should be named like weblogs_controller.rb for
  automated URL mapping. All controllers should descend from
  ApplicationController which itself descends from ActionController::Base.

app/models
  Holds models that should be named like post.rb. Models descend from
  ActiveRecord::Base by default.

app/views
  Holds the template files for the view that should be named like
  weblogs/index.html.erb for the WeblogsController#index action. All views use
  eRuby syntax by default.

app/views/layouts
  Holds the template files for layouts to be used with views. This models the
  common header/footer method of wrapping views. In your views, define a layout
  using the <tt>layout :default</tt> and create a file named default.html.erb.
  Inside default.html.erb, call <% yield %> to render the view using this
  layout.

app/helpers
  Holds view helpers that should be named like weblogs_helper.rb. These are
  generated for you automatically when using generators for controllers.
  Helpers can be used to wrap functionality for your views into methods.

config
  Configuration files for the Rails environment, the routing map, the database,
  and other dependencies.

db
  Contains the database schema in schema.rb. db/migrate contains all the
  sequence of Migrations for your schema.

doc
  This directory is where your application documentation will be stored when
  generated using <tt>rake doc:app</tt>

lib
  Application specific libraries. Basically, any kind of custom code that
  doesn't belong under controllers, models, or helpers. This directory is in
  the load path.

public
  The directory available for the web server. Also contains the dispatchers and the
  default HTML files. This should be set as the DOCUMENT_ROOT of your web
  server.

script
  Helper scripts for automation and generation.

test
  Unit and functional tests along with fixtures. When using the rails generate
  command, template test files will be generated for you and placed in this
  directory.

vendor
  External libraries that the application depends on. Also includes the plugins
  subdirectory. If the app has frozen rails, those gems also go here, under
  vendor/rails/. This directory is in the load path.

我就根据这些帮助文档，以及网络上的帮助文档，尝试跑通第一个rails。

具体的帮助，请参考

http://guides.ruby.tw/rails3/getting_started.html

遇到的问题：

1.ruby与rails版本不匹配。

解决：下载RailsInstaller直接安装。

2.新建项目rails new demo，会在bundle install卡住很久。

解决：

rails new my_app --skip-bundle
cd my_app
bundle install --local

gem install bundler --pre

3.不知道怎么开启服务。

解决：

查看文档

发现到项目目录下dos中，开启rails server即可。

完了到浏览器中输入，localhost:3000就可以看到ruby程序跑通了。

截图如下：