== Welcome to RailsRails is a web-application and persistence framework that includes everythingneeded to create database-backed web-applications according to theModel-View-Control pattern of separation. This pattern splits the view (alsocalled the presentation) into "dumb" templates that are primarily responsiblefor inserting pre-built data in between HTML tags. The model contains the"smart" domain objects (such as Account, Product, Person, Post) that holds allthe business logic and knows how to persist themselves to a database. Thecontroller handles the incoming requests (such as Save New Account, UpdateProduct, 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 mappinglayer entitled Active Record. This layer allows you to present the data fromdatabase rows as objects and embellish these data objects with business logicmethods. 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 bothlayers by its two parts: Action View and Action Controller. These two layersare bundled in a single package due to their heavy interdependence. This isunlike the relationship between the Active Record and Action Pack that is muchmore separate. Each of these packages can be used independently outside ofRails.  You can read more about Action Pack in link:files/vendor/rails/actionpack/README.html.== Getting started1. Run the WEBrick servlet: <tt>ruby script/server</tt> (run with --help for options)   ...or if you have lighttpd installed: <tt>ruby script/lighttpd</tt> (it's faster)2. Go to http://localhost:3000/ and get "Congratulations, you've put Ruby on Rails!"3. Follow the guidelines on the "Congratulations, you've put Ruby on Rails!" screen== Example for Apache conf  <VirtualHost *:80>    ServerName rails    DocumentRoot /path/application/public/    ErrorLog /path/application/log/server.log      <Directory /path/application/public/>      Options ExecCGI FollowSymLinks      AllowOverride all      Allow from all      Order allow,deny    </Directory>  </VirtualHost>NOTE: Be sure that CGIs can be executed in that directory as well. So ExecCGIshould be on and ".cgi" should respond. All requests from 127.0.0.1 gothrough CGI, so no Apache restart is necessary for changes. All other requestsgo through FCGI (or mod_ruby), which requires a restart to show changes.== Debugging RailsHave "tail -f" commands running on both the server.log, production.log, andtest.log files. Rails will automatically display debugging and runtimeinformation to these files. Debugging info will also be shown in the browseron requests from 127.0.0.1.== BreakpointsBreakpoint support is available through the script/breakpointer client. Thismeans that you can break out of execution at any point in the code, investigateand change the model, AND then resume execution! Example:  class WeblogController < ActionController::Base    def index      @posts = Post.find_all      breakpoint "Breaking out from the list"    end  end  So the controller will accept the action, run the first line, then present youwith a IRB prompt in the breakpointer window. Here you can do things like:Executing breakpoint "Breaking out from the list" at .../webrick_server.rb:16 in 'breakpoint'  >> @posts.inspect  => "[#<Post:0x14a6be8 @attributes={\"title\"=>nil, \"body\"=>nil, \"id\"=>\"1\"}>,        #<Post:0x14a6620 @attributes={\"title\"=>\"Rails you know!\", \"body\"=>\"Only ten..\", \"id\"=>\"2\"}>]"  >> @posts.first.title = "hello from a breakpoint"  => "hello from a breakpoint"...and even better is that you can examine how your runtime objects actually work:  >> f = @posts.first   => #<Post:0x13630c4 @attributes={"title"=>nil, "body"=>nil, "id"=>"1"}>  >> f.  Display all 152 possibilities? (y or n)Finally, when you're ready to resume execution, you press CTRL-D== ConsoleYou can interact with the domain model by starting the console through script/console. Here you'll have all parts of the application configured, just like it is when theapplication is running. You can inspect domain models, change values, and save to thedatabase. Starting the script without arguments will launch it in the development environment.Passing an argument will specify a different environment, like <tt>console production</tt>.== Description of contentsapp  Holds all the code that's specific to this particular application.app/controllers  Holds controllers that should be named like weblog_controller.rb for  automated URL mapping. All controllers should descend from  ActionController::Base.app/models  Holds models that should be named like post.rb.  Most models will descend from ActiveRecord::Base.  app/views  Holds the template files for the view that should be named like  weblog/index.rhtml for the WeblogController#index action. All views use eRuby  syntax. This directory can also be used to keep stylesheets, images, and so on  that can be symlinked to public.  app/helpers  Holds view helpers that should be named like weblog_helper.rb.config  Configuration files for the Rails environment, the routing map, the database, and other dependencies.components  Self-contained mini-applications that can bundle together controllers, models, and views.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. Contains subdirectories for images, stylesheets,  and javascripts. Also contains the dispatchers and the default HTML files.script  Helper scripts for automation and generation.test  Unit and functional tests along with fixtures.vendor  External libraries that the application depends on. Also includes the plugins subdirectory.  This directory is in the load path.