0
+Rails is a web-application and persistence framework that includes everything
0
+needed to create database-backed web-applications according to the
0
+Model-View-Control pattern of separation. This pattern splits the view (also
0
+called the presentation) into "dumb" templates that are primarily responsible
0
+for inserting pre-built data in between HTML tags. The model contains the
0
+"smart" domain objects (such as Account, Product, Person, Post) that holds all
0
+the business logic and knows how to persist themselves to a database. The
0
+controller handles the incoming requests (such as Save New Account, Update
0
+Product, Show Post) by manipulating the model and directing data to the view.
0
+In Rails, the model is handled by what's called an object-relational mapping
0
+layer entitled Active Record. This layer allows you to present the data from
0
+database rows as objects and embellish these data objects with business logic
0
+methods. You can read more about Active Record in
0
+link:files/vendor/rails/activerecord/README.html.
0
+The controller and view are handled by the Action Pack, which handles both
0
+layers by its two parts: Action View and Action Controller. These two layers
0
+are bundled in a single package due to their heavy interdependence. This is
0
+unlike the relationship between the Active Record and Action Pack that is much
0
+more separate. Each of these packages can be used independently outside of
0
+Rails. You can read more about Action Pack in
0
+link:files/vendor/rails/actionpack/README.html.
0
+1. At the command prompt, start a new Rails application using the <tt>rails</tt> command
0
+ and your application name. Ex: rails myapp
0
+ (If you've downloaded Rails in a complete tgz or zip, this step is already done)
0
+2. Change directory into myapp and start the web server: <tt>script/server</tt> (run with --help for options)
0
+3. Go to http://localhost:3000/ and get "Welcome aboard: You’re riding the Rails!"
0
+4. Follow the guidelines to start developing your application
0
+By default, Rails will try to use Mongrel and lighttpd if they are installed, otherwise
0
+Rails will use WEBrick, the webserver that ships with Ruby. When you run script/server,
0
+Rails will check if Mongrel exists, then lighttpd and finally fall back to WEBrick. This ensures
0
+that you can always get up and running quickly.
0
+Mongrel is a Ruby-based webserver with a C component (which requires compilation) that is
0
+suitable for development and deployment of Rails applications. If you have Ruby Gems installed,
0
+getting up and running with mongrel is as easy as: <tt>gem install mongrel</tt>.
0
+More info at: http://mongrel.rubyforge.org
0
+If Mongrel is not installed, Rails will look for lighttpd. It's considerably faster than
0
+Mongrel and WEBrick and also suited for production use, but requires additional
0
+installation and currently only works well on OS X/Unix (Windows users are encouraged
0
+to start with Mongrel). We recommend version 1.4.11 and higher. You can download it from
0
+http://www.lighttpd.net.
0
+And finally, if neither Mongrel or lighttpd are installed, Rails will use the built-in Ruby
0
+web server, WEBrick. WEBrick is a small Ruby web server suitable for development, but not
0
+But of course its also possible to run Rails on any platform that supports FCGI.
0
+Apache, LiteSpeed, IIS are just a few. For more information on FCGI,
0
+please visit: http://wiki.rubyonrails.com/rails/pages/FastCGI
0
+Sometimes your application goes wrong. Fortunately there are a lot of tools that
0
+will help you debug it and get it back on the rails.
0
+First area to check is the application log files. Have "tail -f" commands running
0
+on the server.log and development.log. Rails will automatically display debugging
0
+and runtime information to these files. Debugging info will also be shown in the
0
+browser on requests from 127.0.0.1.
0
+You can also log your own messages directly into the log file from your code using
0
+the Ruby logger class from inside your controllers. Example:
0
+ class WeblogController < ActionController::Base
0
+ @weblog = Weblog.find(params[:id])
0
+ logger.info("#{Time.now} Destroyed Weblog ID ##{@weblog.id}!")
0
+The result will be a message in your log file along the lines of:
0
+ Mon Oct 08 14:22:29 +1000 2007 Destroyed Weblog ID #1
0
+More information on how to use the logger is at http://www.ruby-doc.org/core/
0
+Also, Ruby documentation can be found at http://www.ruby-lang.org/ including:
0
+* The Learning Ruby (Pickaxe) Book: http://www.ruby-doc.org/docs/ProgrammingRuby/
0
+* Learn to Program: http://pine.fm/LearnToProgram/ (a beginners guide)
0
+These two online (and free) books will bring you up to speed on the Ruby language
0
+and also on programming in general.
0
+Debugger support is available through the debugger command when you start your Mongrel or
0
+Webrick server with --debugger. This means that you can break out of execution at any point
0
+in the code, investigate and change the model, AND then resume execution! Example:
0
+ class WeblogController < ActionController::Base
0
+ @posts = Post.find(:all)
0
+So the controller will accept the action, run the first line, then present you
0
+with a IRB prompt in the server window. Here you can do things like:
0
+ => "[#<Post:0x14a6be8 @attributes={\"title\"=>nil, \"body\"=>nil, \"id\"=>\"1\"}>,
0
+ #<Post:0x14a6620 @attributes={\"title\"=>\"Rails you know!\", \"body\"=>\"Only ten..\", \"id\"=>\"2\"}>]"
0
+ >> @posts.first.title = "hello from a debugger"
0
+ => "hello from a debugger"
0
+...and even better is that you can examine how your runtime objects actually work:
0
+ => #<Post:0x13630c4 @attributes={"title"=>nil, "body"=>nil, "id"=>"1"}>
0
+ Display all 152 possibilities? (y or n)
0
+Finally, when you're ready to resume execution, you enter "cont"
0
+You can interact with the domain model by starting the console through <tt>script/console</tt>.
0
+Here you'll have all parts of the application configured, just like it is when the
0
+application is running. You can inspect domain models, change values, and save to the
0
+database. Starting the script without arguments will launch it in the development environment.
0
+Passing an argument will specify a different environment, like <tt>script/console production</tt>.
0
+To reload your controllers and models after launching the console run <tt>reload!</tt>
0
+== Description of Contents
0
+ Holds all the code that's specific to this particular application.
0
+ Holds controllers that should be named like weblogs_controller.rb for
0
+ automated URL mapping. All controllers should descend from ApplicationController
0
+ which itself descends from ActionController::Base.
0
+ Holds models that should be named like post.rb.
0
+ Most models will descend from ActiveRecord::Base.
0
+ Holds the template files for the view that should be named like
0
+ weblogs/index.erb for the WeblogsController#index action. All views use eRuby
0
+ Holds the template files for layouts to be used with views. This models the common
0
+ header/footer method of wrapping views. In your views, define a layout using the
0
+ <tt>layout :default</tt> and create a file named default.erb. Inside default.erb,
0
+ call <% yield %> to render the view using this layout.
0
+ Holds view helpers that should be named like weblogs_helper.rb. These are generated
0
+ for you automatically when using script/generate for controllers. Helpers can be used to
0
+ wrap functionality for your views into methods.
0
+ Configuration files for the Rails environment, the routing map, the database, and other dependencies.
0
+ Contains the database schema in schema.rb. db/migrate contains all
0
+ the sequence of Migrations for your schema.
0
+ This directory is where your application documentation will be stored when generated
0
+ using <tt>rake doc:app</tt>
0
+ Application specific libraries. Basically, any kind of custom code that doesn't
0
+ belong under controllers, models, or helpers. This directory is in the load path.
0
+ The directory available for the web server. Contains subdirectories for images, stylesheets,
0
+ and javascripts. Also contains the dispatchers and the default HTML files. This should be
0
+ set as the DOCUMENT_ROOT of your web server.
0
+ Helper scripts for automation and generation.
0
+ Unit and functional tests along with fixtures. When using the script/generate scripts, template
0
+ test files will be generated for you and placed in this directory.
0
+ External libraries that the application depends on. Also includes the plugins subdirectory.
0
+ This directory is in the load path.