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author | James Miller <james@jkmillertech.com> | 2008-09-08 12:36:04 -0700 |
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committer | James Miller <james@jkmillertech.com> | 2008-09-08 12:36:04 -0700 |
commit | f173ead371010af9332f7aa22b1f6cc309cac8a5 (patch) | |
tree | 8ba4a59531e1e7990d64d75961038b268827923a /railties/doc/guides/getting_started_with_rails | |
parent | ba1e3037058dd67d1748f07ef8282ef2082f2001 (diff) | |
download | rails-f173ead371010af9332f7aa22b1f6cc309cac8a5.tar.gz rails-f173ead371010af9332f7aa22b1f6cc309cac8a5.tar.bz2 rails-f173ead371010af9332f7aa22b1f6cc309cac8a5.zip |
Continued work on the MVC/REST section
Diffstat (limited to 'railties/doc/guides/getting_started_with_rails')
-rw-r--r-- | railties/doc/guides/getting_started_with_rails/getting_started_with_rails.txt | 86 |
1 files changed, 54 insertions, 32 deletions
diff --git a/railties/doc/guides/getting_started_with_rails/getting_started_with_rails.txt b/railties/doc/guides/getting_started_with_rails/getting_started_with_rails.txt index b8557dd52a..a798bfa218 100644 --- a/railties/doc/guides/getting_started_with_rails/getting_started_with_rails.txt +++ b/railties/doc/guides/getting_started_with_rails/getting_started_with_rails.txt @@ -16,18 +16,17 @@ This guide is designed for beginners who want to get started with a Rails applic Rails is a web development framework written in the Ruby language. It is designed to make programming web applications easier by making several assumptions about what every developer needs to get started. It allows you to write less code while accomplishing more than other languages and frameworks. == Installing Rails ------------------ -gem install rails ------------------ + +`gem install rails` == Create a new Rails project We're going to create a Rails project called "blog", which is the project that we will build off of for this guide. From your terminal, type: ----------- -rails blog ----------- + +`rails blog` + This will create the a folder in your working directory called "blog". Open up that folder and have a look. For the majority of this tutorial, we will live in the app/ folder, but here's a basic rundown on the function of each folder in a Rails app: [grid="all"] @@ -76,18 +75,18 @@ production: timeout: 5000 -------------------------------------------------------------------- If you're not running OS X 10.5 or greater, you'll need to install the SQLite gem. Similar to installing Rails you just need to run: ------------------------- -gem install sqlite3-ruby ------------------------- + +`gem install sqlite3-ruby` + Because we're using SQLite, there's really nothing else you need to do to setup your database! === Configure MySQL Database .MySQL Tip ******************************* If you want to skip directly to using MySQL on your development machine, type the following will get you setup with a MySQL configuration file that assumes MySQL is running locally and that the root password is blank: ------------------ -rails blog -d mysql ------------------ + +`rails blog -d mysql` + You'll need to make sure you have MySQL up and running on your system with the correct permissions. MySQL installation and configuration is outside the scope of this document. ******************************* If you choose to use MySQL, your +config/database.yml+ will look a little different: @@ -136,19 +135,17 @@ production: socket: /tmp/mysql.sock ---------------------------------------------------------------------- -== Starting the webserver -Rails comes bundled with the lightweight Webrick web server, which (like SQLite) works great in development, but is not designed for a production environment. +== Starting the web server +Rails comes bundled with the lightweight Webrick web server, which (like SQLite) works great in development, but is not designed for a production environment. If you install Mongrel with `gem install mongrel`, Rails will use the Mongrel web server as the default instead (recommended). ******************* If you're interested in alternative web servers for development and/or production, check out mod_rails (a.k.a Passenger) ******************* Rails lets you run in development, test, and production environments (you can also add an unlimited number of additional environments if necessary). In this guide, we're going to work with the development environment only, which is the default when starting the server. From the root of your application folder, simply type the following to startup the web server: ---------------- -./script/server ---------------- -This will start a process that allows you to connect to your application via a web browser on port 3000. Open up a browser to: ----------------------- -http://localhost:3000/ ----------------------- + +`./script/server` + +This will start a process that allows you to connect to your application via a web browser on port 3000. Open up a browser to +http://localhost:3000/+ + You should see the "Welcome Aboard" default Rails screen, and can click on the "About your application's environment" link to see a brief summary of your current configuration. If you've gotten this far, you're riding rails! Let's dive into the code! == Models, Views, and Controllers @@ -158,20 +155,21 @@ Rails uses Model, View, Controller (MVC) architecture because it isolates busine The model represents the information (data) of the application and the rules to manipulate that data. In the case of Rails, models are primarily used for managing the rules of interaction with a corresponding database table. Assume that for every table in your database, you will have a corresponding model (not necessarily the other way around, but that's beyond the scope of this guide). Models in Rails use a singular name, and their corresponding database tables use a plural name. In the case of our "Blog" application, we're going to need a table for our blog posts. Because we're generating a model, we want to use the singular name: ----------------------------- -./script/generate model Post ----------------------------- + +`./script/generate model Post` + You'll see that this generates several files, we're going to focus on two. First, let's take a look at +app/models/post.rb+ ------------------------------- class Post < ActiveRecord::Base end ------------------------------- -This is what each model you create will look like by default. Here Rails is making the assumption that your Post model will be tied to a database, because it is telling the Post class to inherit from the ActiveRecord::Base class, which is where all the database magic happens. Let's leave the model alone for now and move onto migrations. +This is what each model you create will look like by default. Here Rails is making the assumption that your Post model will be tied to a database, because it is telling the Post class to descend from the ActiveRecord::Base class, which is where all the database magic happens. Let's leave the model alone for now and move onto migrations. ==== Migrations Database migrations make it simple to add/remove/modify tables, columns, and indexes while allowing you to roll back or forward between states with ease. Have a look at +db/migrate/2008XXXXXXXXXX_create_posts.rb+ (Yours will have numbers specific to the time that the file was generated), which was generated when creating our Post model: + ------------------------------------------- class CreatePosts < ActiveRecord::Migration def self.up @@ -186,9 +184,11 @@ class CreatePosts < ActiveRecord::Migration end end ------------------------------------------- + By default, Rails creates a database migration that will create the table for "posts" (plural name of model). The +create_table+ method takes a ruby block, and by default you'll see +t.timestamps+ in there, which automatically creates and automatically handles +created_at+ and +updated_at+ datetime columns. The +self.up+ section handles progression of the database, whereas the +self.down+ handles regression (or rollback) of the migration. Let's add some more columns to our migration that suit our post table. We'll create a +name+ column for the person who wrote the post, a +title+ column for the title of the post, and a +content+ column for the actual post content. + ------------------------------------------- class CreatePosts < ActiveRecord::Migration def self.up @@ -206,9 +206,9 @@ class CreatePosts < ActiveRecord::Migration end ------------------------------------------- Now that we have our migration just right, we can run the migration (the +self.up+ portion) by returning to the terminal and running: ---------------- -rake db:migrate ---------------- + +`rake db:migrate` + This command will always run any migrations that have not yet been run. .Singular and Plural Inflections @@ -223,21 +223,43 @@ The controller communicates input from the user (the view) to the model. The REST idea will likely take some time to wrap your brain around if you're new to the concept. But know the following: * It is best to keep your controllers RESTful at all times if possible -* Resources must be defined in +config/routes.rb+ in order for the RESTful architecture to work properly +* Resources must be defined in +config/routes.rb+ in order for the RESTful architecture to work properly, so let's add that now: -------------------- map.resources :posts -------------------- -* The seven actions that are automatically part of the RESTful design in Rails are +index+, +show+, +create+, +edit+, +update+, and +destroy+ +* The seven actions that are automatically part of the RESTful design in Rails are +index+, +show+, +new+, +create+, +edit+, +update+, and +destroy+. -=== The View -The view is where you put all the code that gets seen by the user: divs, tables, text, checkboxes, etc. Think of the view as the home of your HTML. If done correctly, there should be no business logic in the view. +Let's generate a controller: + +`./script/generate controller Posts` + +Open up the controller that it generates in +app/controllers/posts_controller.rb+. It should look like: +--------------------------------------------- +class PostsController < ApplicationController +end +--------------------------------------------- +Because of the +map.resources :posts+ line in your +config/routes.rb+ file, this controller is ready to take on all seven actions listed above. But we're going to need some logic in this controller in order to interact with the model, and we're going to need to generate our view files so the user can interact with your application from their browser. + +We're going to use the scaffold generator to create all the files and basic logic to make this work, now that you know how to generate models and controllers manually. + +To do that, let's completely start over. Back out of your Rails project folder, and *remove it completely* (`rm -rf blog`). +Create the project again and enter the directory by running the commands: + +`rails blog` +`cd blog` +=== Rails Scaffold +Whenever you are dealing with a resource and you know you'll need a way to manage that resource in your application, you can start by generating a scaffold. The reason that this guide did not start with generating the scaffold is because it is not all that useful once you For our blog, we want our "Post" resource, so let's generate that now: +`./script/generate scaffold Post name:string title:string content:text` +=== The View +The view is where you put all the code that gets seen by the user: divs, tables, text, checkboxes, etc. Think of the view as the home of your HTML. If done correctly, there should be no business logic in the view. + |