README
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r2376 | == Welcome to Rails | ||
Rails is a web-application and persistence framework that includes everything | ||||
needed to create database-backed web-applications according to the | ||||
Model-View-Control pattern of separation. 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 | ||||
1. 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 ExecCGI | ||||
should be on and ".cgi" should respond. All requests from 127.0.0.1 go | ||||
through CGI, so no Apache restart is necessary for changes. All other requests | ||||
go through FCGI (or mod_ruby), which requires a restart to show changes. | ||||
== Debugging Rails | ||||
Have "tail -f" commands running on both the server.log, production.log, and | ||||
test.log files. 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. | ||||
== Breakpoints | ||||
Breakpoint support is available through the script/breakpointer client. This | ||||
means that you can break out of execution at any point in the code, investigate | ||||
and 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 you | ||||
with 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 | ||||
== Console | ||||
You 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 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. | ||||
Passing an argument will specify a different environment, like <tt>console production</tt>. | ||||
== Description of contents | ||||
app | ||||
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. | ||||