Ruby

Facebook Twitter

Rolling with Ruby on Rails Revisited, Part 2. By Bill Walton 01/05/2007 Editor's note: this is the second part of Rolling with Ruby on Rails Revisited, an update to Curt Hibbs's influential Rolling with Ruby on Rails and Rolling with Ruby on Rails Part 2.

Rolling with Ruby on Rails Revisited, Part 2

Also check out Bill Walton's monthly series, Cookin' With Ruby on Rails. NOTE TO READER: This tutorial is intended for use with Rails 1.2.6. It has not yet been updated to support Rails 2.x. Paul: Good pizza. Boss: Actually, Paul, I'm pretty interested in seeing that myself. CB: No problem. Figure 12. Boss: That's quite a bit of code, and I get most of it. CB: That's one of the differences between a real web-based application and site that's just a bunch of static pages with some scripting, Boss. Boss: OK. Paul: Sure, Boss. CB: OK, then. I tell Rails about the relationship between recipes and categories in their models. Has_many :recipes Figure 13.

Belongs_to :category Figure 14. Now Rails knows about the relationship between the two models. RailsPlayTime. Ruby on Rails Documentation. Intermediate Rails: Understanding Models, Views and Controllers. I’m glad people liked the introduction to Rails; now you scallawags get to avoid my headaches with the model-view-controller (MVC) pattern.

Intermediate Rails: Understanding Models, Views and Controllers

This isn’t quite an intro to MVC, it’s a list of gotchas as you plod through MVC the first few times. Here’s the big picture as I understand it: The browser makes a request, such as web server (mongrel, WEBrick, etc.) receives the request. It uses routes to find out which controller to use: the default route pattern is “/controller/action/id” as defined in config/routes.rb. In our case, it’s the “video” controller, method “show”, id “15″. It’s more fun to imagine a story with “fat model, skinny controller” instead of a sterile “3-tiered architecture”. Many MVC discussions ignore the role of the web server. SuperModels Models are fat in Railsville: they do the heavy lifting so the controller stays lean, mean, and ignorant of the details. Using ActiveRecord class User < ActiveRecord::Base end Ruby can also handle “undefined” methods with ease.

Becomes. What is ruby? Ruby is "an interpreted scripting language for quick and easy object-oriented programming" -- what does this mean?

What is ruby?

Interpreted scripting language: ability to make operating system calls directlypowerful string operations and regular expressionsimmediate feedback during development quick and easy: variable declarations are unnecessaryvariables are not typedsyntax is simple and consistentmemory management is automatic object oriented programming: everything is an objectclasses, methods, inheritance, etc.singleton methods"mixin" functionality by moduleiterators and closures also: multiple precision integersconvenient exception processingdynamic loadingthreading support If you are unfamiliar with some of the concepts above, read on, and don't worry.

String. Str % arg → new_str click to toggle source Format—Uses str as a format specification, and returns the result of applying it to arg.

String

If the format specification contains more than one substitution, then arg must be an Array or Hash containing the values to be substituted. See Kernel::sprintf for details of the format string. static VALUE rb_str_format_m(VALUE str, VALUE arg) { volatile VALUE tmp = rb_check_array_type(arg); if (! NIL_P(tmp)) { return rb_str_format(RARRAY_LENINT(tmp), RARRAY_PTR(tmp), str); } return rb_str_format(1, &arg, str); } str * integer → new_str click to toggle source Copy—Returns a new String containing integer copies of the receiver.

"Ho! Str + other_str → new_str click to toggle source Concatenation—Returns a new String containing other_str concatenated to str. "Hello from " + self.to_s.