Rails вкратце

Rails in a Nutshell

Chapter 1. Rails

What makes you happy?

Programmer happiness comes from being able to quickly and correctly express the ideas you’ve got in your head so it’s easy for another person to understand and build on.

Surprises in code behaviour, having to repeat yourself, chores like filling out configuration files, designing a directory structure convention to keep everything in and finding libraries to do what you need are all common obstacles.

Rails sidesteps these problems by being predictable, following the DRY* principle whereever possible by coming with well-chosen defaults to minimize configuration chores, an easily-navigated file-structure, and bundled libraries for what you’re probably going to be doing with a web application – altogether, the general idea is convention over configuration.

By building an application with Rails, you get to concentrate on your own problem instead of those that have been solved already.

Architecture

After you’ve written a few web applications, you pick up on some patterns about how they’re best built and maintained.

Typically, there are three archaetypical team members working on it: a business person, a designer, and a manager to glue everything together when results need to be delivered. These experts perform better when they have complete control over their own domains, so give them space—separate all their code, and only let them talk to each other through explicitly defined public methods.

This idea of keeping concerns separate when it comes to business logic, presentation, and bringing it all together is formally known as the Model View Controller (MVC) pattern. Rails is built on this idea of separating concerns.

Model

A model contains business logic – whether or not to ship something somewhere, send a happy birthday notification, or launch a space ship. They act as models, or representations of things in real life. These decisions are often made based on past events, so a database is usually involved.

Rails handles the conversation with the database with ActiveRecord, leaving you to just fill in the parts relative to your business. Tests are done through the bundled UnitTest package.