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| -== Welcome to Rails |
| 1 | +== Exemplo usando a gem css_sprite == |
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|
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| -Rails is a web-application framework that includes everything needed to create |
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| -database-backed web applications according to the Model-View-Control pattern. |
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|
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| -This pattern splits the view (also called the presentation) into "dumb" templates |
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| -that are primarily responsible for inserting pre-built data in between HTML tags. |
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| -The model contains the "smart" domain objects (such as Account, Product, Person, |
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| -Post) that holds all the business logic and knows how to persist themselves to |
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| -a database. The controller handles the incoming requests (such as Save New Account, |
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| -Update Product, Show Post) by manipulating the model and directing data to the view. |
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| - |
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| -In Rails, the model is handled by what's called an object-relational mapping |
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| -layer entitled Active Record. This layer allows you to present the data from |
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| -database rows as objects and embellish these data objects with business logic |
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| -methods. You can read more about Active Record in |
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| -link:files/vendor/rails/activerecord/README.html. |
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| - |
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| -The controller and view are handled by the Action Pack, which handles both |
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| -layers by its two parts: Action View and Action Controller. These two layers |
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| -are bundled in a single package due to their heavy interdependence. This is |
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| -unlike the relationship between the Active Record and Action Pack that is much |
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| -more separate. Each of these packages can be used independently outside of |
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| -Rails. You can read more about Action Pack in |
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| -link:files/vendor/rails/actionpack/README.html. |
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| - |
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| - |
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| -== Getting Started |
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| - |
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| -1. At the command prompt, start a new Rails application using the <tt>rails</tt> command |
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| - and your application name. Ex: rails myapp |
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| -2. Change directory into myapp and start the web server: <tt>script/server</tt> (run with --help for options) |
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| -3. Go to http://localhost:3000/ and get "Welcome aboard: You're riding the Rails!" |
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| -4. Follow the guidelines to start developing your application |
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| - |
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| - |
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| -== Web Servers |
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| - |
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| -By default, Rails will try to use Mongrel if it's are installed when started with script/server, otherwise Rails will use WEBrick, the webserver that ships with Ruby. But you can also use Rails |
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| -with a variety of other web servers. |
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| - |
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| -Mongrel is a Ruby-based webserver with a C component (which requires compilation) that is |
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| -suitable for development and deployment of Rails applications. If you have Ruby Gems installed, |
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| -getting up and running with mongrel is as easy as: <tt>gem install mongrel</tt>. |
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| -More info at: http://mongrel.rubyforge.org |
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| - |
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| -Say other Ruby web servers like Thin and Ebb or regular web servers like Apache or LiteSpeed or |
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| -Lighttpd or IIS. The Ruby web servers are run through Rack and the latter can either be setup to use |
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| -FCGI or proxy to a pack of Mongrels/Thin/Ebb servers. |
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| - |
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| -== Apache .htaccess example for FCGI/CGI |
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| - |
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| -# General Apache options |
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| -AddHandler fastcgi-script .fcgi |
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| -AddHandler cgi-script .cgi |
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| -Options +FollowSymLinks +ExecCGI |
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| - |
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| -# If you don't want Rails to look in certain directories, |
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| -# use the following rewrite rules so that Apache won't rewrite certain requests |
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| -# |
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| -# Example: |
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| -# RewriteCond %{REQUEST_URI} ^/notrails.* |
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| -# RewriteRule .* - [L] |
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| - |
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| -# Redirect all requests not available on the filesystem to Rails |
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| -# By default the cgi dispatcher is used which is very slow |
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| -# |
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| -# For better performance replace the dispatcher with the fastcgi one |
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| -# |
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| -# Example: |
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| -# RewriteRule ^(.*)$ dispatch.fcgi [QSA,L] |
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| -RewriteEngine On |
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| - |
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| -# If your Rails application is accessed via an Alias directive, |
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| -# then you MUST also set the RewriteBase in this htaccess file. |
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| -# |
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| -# Example: |
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| -# Alias /myrailsapp /path/to/myrailsapp/public |
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| -# RewriteBase /myrailsapp |
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| - |
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| -RewriteRule ^$ index.html [QSA] |
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| -RewriteRule ^([^.]+)$ $1.html [QSA] |
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| -RewriteCond %{REQUEST_FILENAME} !-f |
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| -RewriteRule ^(.*)$ dispatch.cgi [QSA,L] |
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| - |
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| -# In case Rails experiences terminal errors |
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| -# Instead of displaying this message you can supply a file here which will be rendered instead |
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| -# |
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| -# Example: |
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| -# ErrorDocument 500 /500.html |
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| - |
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| -ErrorDocument 500 "<h2>Application error</h2>Rails application failed to start properly" |
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| - |
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| - |
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| -== Debugging Rails |
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| - |
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| -Sometimes your application goes wrong. Fortunately there are a lot of tools that |
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| -will help you debug it and get it back on the rails. |
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| - |
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| -First area to check is the application log files. Have "tail -f" commands running |
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| -on the server.log and development.log. Rails will automatically display debugging |
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| -and runtime information to these files. Debugging info will also be shown in the |
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| -browser on requests from 127.0.0.1. |
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| - |
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| -You can also log your own messages directly into the log file from your code using |
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| -the Ruby logger class from inside your controllers. Example: |
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| - |
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| - class WeblogController < ActionController::Base |
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| - def destroy |
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| - @weblog = Weblog.find(params[:id]) |
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| - @weblog.destroy |
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| - logger.info("#{Time.now} Destroyed Weblog ID ##{@weblog.id}!") |
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| - end |
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| - end |
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| - |
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| -The result will be a message in your log file along the lines of: |
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| - Mon Oct 08 14:22:29 +1000 2007 Destroyed Weblog ID #1 |
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| - |
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| -More information on how to use the logger is at http://www.ruby-doc.org/core/ |
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| - |
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| -Also, Ruby documentation can be found at http://www.ruby-lang.org/ including: |
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| - |
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| -* The Learning Ruby (Pickaxe) Book: http://www.ruby-doc.org/docs/ProgrammingRuby/ |
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| -* Learn to Program: http://pine.fm/LearnToProgram/ (a beginners guide) |
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| - |
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| -These two online (and free) books will bring you up to speed on the Ruby language |
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| -and also on programming in general. |
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| - |
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| - |
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| -== Debugger |
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| - |
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| -Debugger support is available through the debugger command when you start your Mongrel or |
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| -Webrick server with --debugger. This means that you can break out of execution at any point |
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| -in the code, investigate and change the model, AND then resume execution! |
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| -You need to install ruby-debug to run the server in debugging mode. With gems, use 'gem install ruby-debug' |
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| -Example: |
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| - |
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| - class WeblogController < ActionController::Base |
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| - def index |
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| - @posts = Post.find(:all) |
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| - debugger |
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| - end |
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| - end |
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| - |
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| -So the controller will accept the action, run the first line, then present you |
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| -with a IRB prompt in the server window. Here you can do things like: |
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| - |
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| - >> @posts.inspect |
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| - => "[#<Post:0x14a6be8 @attributes={\"title\"=>nil, \"body\"=>nil, \"id\"=>\"1\"}>, |
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| - #<Post:0x14a6620 @attributes={\"title\"=>\"Rails you know!\", \"body\"=>\"Only ten..\", \"id\"=>\"2\"}>]" |
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| - >> @posts.first.title = "hello from a debugger" |
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| - => "hello from a debugger" |
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| - |
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| -...and even better is that you can examine how your runtime objects actually work: |
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| - |
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| - >> f = @posts.first |
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| - => #<Post:0x13630c4 @attributes={"title"=>nil, "body"=>nil, "id"=>"1"}> |
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| - >> f. |
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| - Display all 152 possibilities? (y or n) |
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| - |
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| -Finally, when you're ready to resume execution, you enter "cont" |
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| - |
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| - |
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| -== Console |
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| - |
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| -You can interact with the domain model by starting the console through <tt>script/console</tt>. |
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| -Here you'll have all parts of the application configured, just like it is when the |
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| -application is running. You can inspect domain models, change values, and save to the |
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| -database. Starting the script without arguments will launch it in the development environment. |
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| -Passing an argument will specify a different environment, like <tt>script/console production</tt>. |
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| - |
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| -To reload your controllers and models after launching the console run <tt>reload!</tt> |
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| - |
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| -== dbconsole |
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| - |
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| -You can go to the command line of your database directly through <tt>script/dbconsole</tt>. |
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| -You would be connected to the database with the credentials defined in database.yml. |
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| -Starting the script without arguments will connect you to the development database. Passing an |
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| -argument will connect you to a different database, like <tt>script/dbconsole production</tt>. |
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| -Currently works for mysql, postgresql and sqlite. |
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| - |
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| -== Description of Contents |
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| - |
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| -app |
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| - Holds all the code that's specific to this particular application. |
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| - |
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| -app/controllers |
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| - Holds controllers that should be named like weblogs_controller.rb for |
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| - automated URL mapping. All controllers should descend from ApplicationController |
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| - which itself descends from ActionController::Base. |
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| - |
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| -app/models |
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| - Holds models that should be named like post.rb. |
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| - Most models will descend from ActiveRecord::Base. |
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| - |
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| -app/views |
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| - Holds the template files for the view that should be named like |
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| - weblogs/index.html.erb for the WeblogsController#index action. All views use eRuby |
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| - syntax. |
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| - |
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| -app/views/layouts |
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| - Holds the template files for layouts to be used with views. This models the common |
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| - header/footer method of wrapping views. In your views, define a layout using the |
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| - <tt>layout :default</tt> and create a file named default.html.erb. Inside default.html.erb, |
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| - call <% yield %> to render the view using this layout. |
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| - |
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| -app/helpers |
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| - Holds view helpers that should be named like weblogs_helper.rb. These are generated |
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| - for you automatically when using script/generate for controllers. Helpers can be used to |
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| - wrap functionality for your views into methods. |
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| - |
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| -config |
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| - Configuration files for the Rails environment, the routing map, the database, and other dependencies. |
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| - |
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| -db |
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| - Contains the database schema in schema.rb. db/migrate contains all |
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| - the sequence of Migrations for your schema. |
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| - |
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| -doc |
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| - This directory is where your application documentation will be stored when generated |
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| - using <tt>rake doc:app</tt> |
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| - |
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| -lib |
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| - Application specific libraries. Basically, any kind of custom code that doesn't |
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| - belong under controllers, models, or helpers. This directory is in the load path. |
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| - |
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| -public |
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| - The directory available for the web server. Contains subdirectories for images, stylesheets, |
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| - and javascripts. Also contains the dispatchers and the default HTML files. This should be |
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| - set as the DOCUMENT_ROOT of your web server. |
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| - |
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| -script |
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| - Helper scripts for automation and generation. |
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| - |
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| -test |
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| - Unit and functional tests along with fixtures. When using the script/generate scripts, template |
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| - test files will be generated for you and placed in this directory. |
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| - |
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| -vendor |
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| - External libraries that the application depends on. Also includes the plugins subdirectory. |
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| - If the app has frozen rails, those gems also go here, under vendor/rails/. |
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| - This directory is in the load path. |
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