<price type="decimal">29.95</price>
<title>Pragmatic Project Automation</title>
<orders>
<order>
<address>dp</address>
<email>ilm</email>
<id type="integer">1</id>
<name>china</name>
<pay-type>cc</pay-type>
</order>
<order>
<address>china</address>
<email>[email]ilmf@eyou.com[/email]</email>
<id type="integer">2</id>
<name>lee</name>
<pay-type>cc</pay-type>
</order>
<order>
<address>lfjs</address>
<email>[email]fjd@china.com[/email]</email>
<id type="integer">3</id>
<name>chinaren</name>
<pay-type>cc</pay-type>
</order>
<order>
<address>dkf</address>
<email>[email]zllichO@eyou.com[/email]</email>
<id type="integer">4</id>
<name>zllicho</name>
<pay-type>check</pay-type>
</order>
</orders>
</product>
可以看到，默认情况下，to_xml方法会导出对象的所有信息。也可以要求它屏蔽某些属性，但这容易让代码变得凌乱。如果希望生成的XML符合特定的schema或者DTD，最后还是使用rxml模板。
扫尾工作
编程已经结束了，不过在将应用程序部署到生产环境之前，做一些整理工作。
为应用程序提供一份完整的文档。在Rails中可以运行Ruby提供的RDoc工具，为应用程序的所有源文件生成漂亮的开发者文档，不过在生成这些文档之前，可能需要创建一个介绍性的页面。这样未来开发者才会知道应用程序到底干了什么。为此编辑doc/README_FOR_APP文件，在里面写上有用的东西。稍后RDoc会对这个文件进行处理，所以可以随便在里面使用什么格式。
= The Depot Online Store
This application implements an online store, with a catalog, cart, and orders.
It is divided into three main sections:
* The buyer's side of the application manages the catalog, cart, and
checkout. It is implemented in StoreController and the associated
views.
* Only administrators can access stuff in the AdminController.
This is implemented by the LoginController, and is enforced by the
ApplicationController#authorize method.
* There's also a simple web service accessible via the InfoController.
This code was produced as an example for the book {Agile Web
Development with
Rails}[[url]http://pragmaticprogrammer.com/titles/rails2[/url]]. It should not be
run as a real online store.
=== Author
Dave Thomas, The Pragmatic Programmers, LLC
=== Warranty
This code is provided for educational purposes only, and comes with
absolutely no warranty. It should not be used in live applications.
== Copyright
This code is Copyright (c) 2006 The Pragmatic Programmers, LLC.
It is released under the same license as Ruby.
然后，用rake命令就可以生成HTML格式的文档。(/doc/app)
depot>rake doc:app
最后，想看看自己编写了多少代码，有一个rake任务可以完成
depot>rake stats
MVC
Model负责维持应用程序的状态。不仅是数据的容器，还是数据的监护者。
View生成用户界面，通常会根据模型中的数据来生成。
Controller负责协调整个应用程序的运转。控制器接收来自外界的事件，与Model进行交互，并将合适的view展现给用户。
本文转自 fsjoy1983 51CTO博客，原文链接：http://blog.51cto.com/fsjoy/75615，如需转载请自行联系原作者
