Ruby Cookbook

Recipe 15.1. Writing a Simple Rails Application to Show System Status Problem You would like to get started with Rails by building a very simple application. Solution This example displays the running processes on a Unix system. I...

Recipe 15.2. Passing Data from the Controller to the View Problem You want to pass data between a controller and its views. Solution The view is an ERB template that is interpreted within the context of its controller object. A view ...

Recipe 15.3. Creating a Layout for Your Header and Footer Problem You want to create a header and footer for every page on your web application. Certain pages should have special headers and footers, and you may want to dynami...

Recipe 15.4. Redirecting to a Different Location Problem You want to redirect your user to another of your application's actions, or to an external URL. Solution The class ActionController::Base (superclass of ApplicationController) defin...

Recipe 15.5. Displaying Templates with Render Problem Rails's default mapping of one action method to one view template is not flexible enough for you. You want to customize the template that gets rendered for a particular action by callin...

Recipe 15.6. Integrating a Database with Your Rails Application Problem You want your web application to store persistent data in a relational database. Solution The hardest part is setting things up: creating your database and ...

Recipe 15.7. Understanding Pluralization Rules Problem You want to understand and customize Rails's rules for automatically pluralizing nouns. Solution You can use Rails' pluralization functionality in any part of your application...

Recipe 15.8. Creating a Login System Problem You want your application to support a login system based on user accounts. Users will log in with a unique username and password, as in most commercial and community web sites. Solution C...

Recipe 15.9. Storing Hashed User Passwords in the Database Problem The database table defined in Recipe 15.8 stores users' passwords as plain text. This is a bad idea: if someone compromises the database, she will have all of your users' passwo...

Recipe 15.10. Escaping HTML and JavaScript for Display Problem You want to display data that might contain HTML or JavaScript without making browsers render it as HTML or interpret the JavaScript. This is especially important when dis...

Recipe 15.11. Setting and Retrieving Session Information Problem You want to associate some data with each distinct web client that's using your application. The data needs to persist across HTTP requests. Solution You can use cookies (se...

Recipe 15.12. Setting and Retrieving Cookies Problem You want to set a cookie from within Rails. Solution Recall from Recipe 15.11 that all Rails controllers, views, helpers, and mailers have access to a method called sessions that r...

Recipe 15.13. Extracting Code into Helper Functions Problem Your views are getting cluttered with Ruby code. Solution Let's create a controller with a fairly complex view to see how this can happen: $ ./scripts/gener...

Recipe 15.14. Refactoring the View into Partial Snippets of Views Problem Your view doesn't contain a lot of Ruby code, but it's still becoming more complicated than you'd like. You'd like to refactor the view logic into separate, reusable temp...

Recipe 15.15. Adding DHTML Effects with script.aculo.us Problem You want to add fancy effects such as fades to your application, without writing any JavaScript. Solution Every Rails application comes bundled with some JavaScr...

Recipe 15.16. Generating Forms for Manipulating Model Objects Problem You want to define actions that let a user create or edit objects stored in the database. Solution Let's create a simple model, and then build forms for it. H...

Recipe 15.17. Creating an Ajax Form Problem You want to build a web application that's responsive and easy to use. You don't want your users to spend lots of time waiting around for the browser to redraw the screen. Solution You can use J...

Recipe 15.18. Exposing Web Services on Your Web Site Problem You want to offer SOAP and XML-RPC web services from your web application. Solution Rails comes with a built-in web service generator that makes it easy to expose a con...

Recipe 15.19. Sending Mail with Rails Problem You want to send an email from within your Rails application: perhaps a confirmation of an order, or notification that some action has been taken on a user's behalf. Solution The first is t...

Recipe 15.20. Automatically Sending Error Messages to Your Email Problem You want to receive a descriptive email message every time one of your users encounters an application error. Solution Any errors that occur while running your ap...

Recipe 15.21. Documenting Your Web Site Problem You want to document the controllers, models, and helpers of your web application so that the developers responsible for maintaining the application can understand how it works. Solution...

Recipe 15.22. Unit Testing Your Web Site Problem You want to create a suite of automated tests that test the functionality of your Rails application. Solution Rails can't write your test code any more than it can write your view...