DataMapper的使用与现有的Rails应用程序 [英] Using Datamapper with existing rails application

问题描述

我有一个现有的Rails 3应用程序中使用的ActiveRecord，我想切换到的DataMapper。在DM-轨页给出的说明只说说创建一个新的应用程序。有谁知道如何扔掉所有的ActiveRecord依赖关系，并迁移到DataMapper的？

I have an existing Rails 3 application using ActiveRecord, and I want to switch to Datamapper. The instructions given in the dm-rails page only talk about creating a new application. Does anyone know how to throw away all activerecord dependancies and migrate to datamapper?

谢谢！

推荐答案

这是realtively简单，但也有几件事情你需要做的。

It's realtively straightforward, but there are a couple of things you need to do.

在你的Gemfile，删除轨道，而是需要把下面的。

In your Gemfile, remove "rails" and instead require the following.

gem 'activesupport',      RAILS_VERSION, :require => 'active_support'
gem 'actionpack',         RAILS_VERSION, :require => 'action_pack'
gem 'actionmailer',       RAILS_VERSION, :require => 'action_mailer'
gem 'railties',           RAILS_VERSION, :require => 'rails'

其中， RAILS_VERSION 是Rails的，你要使用的版本（例如〜＆GT; 3.1 ）。这基本上是所有的轨道，除了ActiveRecord的。

Where RAILS_VERSION is the version of Rails you want to use (e.g. ~> 3.1). This is basically all of rails except ActiveRecord.

在配置/ application.rb中的顶部，去掉要求对轨（我忘了原来要求的样子），取而代之的是与特定的需要您需要的railties。

At the top of config/application.rb, remove the require for rails (I forget what the original require looks like) and replace it with specific requires for the railties you need.

require "action_controller/railtie"
require "action_mailer/railtie"

我想唯一的另一种是测试::单位railtie，但我们不使用测试::单位，所以我们不包括它。

I think the only other one is a Test::Unit railtie, but we're not using Test::Unit, so we don't include it.

最后，如果你想使用标识映射（我建议你做，但它并不需要），发生在你的ApplicationController的类主体：

Finally, if you want to use the identity map (I suggest you do, but it's not needed), place in your ApplicationController's class body:

use Rails::DataMapper::Middleware::IdentityMap

这应该是一切;根据README剩下的只是配置的database.yml（它的pretty的多交叉兼容标准轨了一艘）。

That should be everything; the rest is just configuring your database.yml according to the README (it's pretty much cross-compatible with a standard rails one anyway).

作为参考，看看什么样的发电机的作用：

For reference, take a look at what the generators does:

-zsh$  curl http://datamapper.org/templates/rails.rb
apply 'http://datamapper.org/templates/rails/gemfile.rb'
apply 'http://datamapper.org/templates/rails/application.rb'

如果你看一下这两个文件的内容，你会看到多余的东西，你会得到，如果你已经使用发电机。

If you look at the contents of those two files you'll see the extra stuff you'd get if you had used the generator.

这篇关于DataMapper的使用与现有的Rails应用程序的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！