BlogJava-火星中转站-随笔分类-Ruby On Rails

Rails中namespace的layout

Martian — Wed, 15 Apr 2009 02:57:00 GMT

在rails中提供了namespace的功能，但是如何实现namespace的layout呢？
假如这样一个场景：
routes.rb中这样定义:

map.namespace :admin do |admin|
admin.resources :articles
admin.resources :tags
end

需要对articles,tags提供一个统一的后台管理界面，根据rails中的layout功能，猜想是否会有layouts/admin.html.erb这样一个针对namespace的模板页，但尝试后发现根据不行，下面是google到的一个问题：

Do controllers in namespaces somehow get their own default layout
file?  For instance, the UsersController will use layouts/users.rhtml
if it exists.  Is there something similar for Admin::UsersController
or will it default to the same file?  I tried layouts/
admin_users.rhtml and layouts/admin/users.rhtml with no luck.

他也尝试了同样的问题，layouts/users.rhtml, layouts/admin_users.rhtml, layouts/admin/users.rhtml，都是no luck.

这里可以使用一个取巧的方法，在controller中可以通过layout 方法来指定使用哪个模板页，这里可以写一个BaseController:

class Admin::BaseController < ApplicationController
layout 'admin'
end

在BaseController中指定模板页为admin.html.erb

然后将articles和tags的Controller都改为继承自BaseController。

Martian 2009-04-15 10:57 发表评论

Rails中的namespace

Martian — Fri, 10 Apr 2009 08:56:00 GMT

在Rails中可以通过namespace来管理controller。
首先生成scaffold:
script/generate scaffold article title:string body:text
在routes.rb中添加如下路由：

map.namespace :admin do |admin|
admin.resources :articles
end

由意味着给article增加了一个名为admin的namespace,将controllers中的articles_controller.rb修改为controllers/admin/articles_controller.rb，也就是将这个控制器放到admin这个文件夹中。

先看一下相应的路由规则,执行rake roures:

              admin_articles GET    /admin/articles                  {:action=>"index", :controller=>"admin/articles"}
    formatted_admin_articles GET    /admin/articles.:format          {:action=>"index", :controller=>"admin/articles"}
                             POST   /admin/articles                  {:action=>"create", :controller=>"admin/articles"}
                             POST   /admin/articles.:format          {:action=>"create", :controller=>"admin/articles"}
           new_admin_article GET    /admin/articles/new              {:action=>"new", :controller=>"admin/articles"}
formatted_new_admin_article GET    /admin/articles/new.:format      {:action=>"new", :controller=>"admin/articles"}
          edit_admin_article GET    /admin/articles/:id/edit         {:action=>"edit", :controller=>"admin/articles"}
formatted_edit_admin_article GET    /admin/articles/:id/edit.:format {:action=>"edit", :controller=>"admin/articles"}
               admin_article GET    /admin/articles/:id              {:action=>"show", :controller=>"admin/articles"}
     formatted_admin_article GET    /admin/articles/:id.:format      {:action=>"show", :controller=>"admin/articles"}
                             PUT    /admin/articles/:id              {:action=>"update", :controller=>"admin/articles"}
                             PUT    /admin/articles/:id.:format      {:action=>"update", :controller=>"admin/articles"}
                             DELETE /admin/articles/:id              {:action=>"destroy", :controller=>"admin/articles"}

                             DELETE /admin/articles/:id.:format      {:action=>"destroy", :controller=>"admin/articles"}

                                    /:controller/:action/:id
                                    /:controller/:action/:id.:format

对比一下不加admin这个namespace时的路由：

          article_index GET    /article                         {:action=>"index", :controller=>"article"}
formatted_article_index GET    /article.:format                 {:action=>"index", :controller=>"article"}
                        POST   /article                         {:action=>"create", :controller=>"article"}
                        POST   /article.:format                 {:action=>"create", :controller=>"article"}
            new_article GET    /article/new                     {:action=>"new", :controller=>"article"}
  formatted_new_article GET    /article/new.:format             {:action=>"new", :controller=>"article"}
           edit_article GET    /article/:id/edit                {:action=>"edit", :controller=>"article"}
formatted_edit_article GET    /article/:id/edit.:format        {:action=>"edit", :controller=>"article"}
                article GET    /article/:id                     {:action=>"show", :controller=>"article"}
      formatted_article GET    /article/:id.:format             {:action=>"show", :controller=>"article"}
                        PUT    /article/:id                     {:action=>"update", :controller=>"article"}
                        PUT    /article/:id.:format             {:action=>"update", :controller=>"article"}
                        DELETE /article/:id                     {:action=>"destroy", :controller=>"article"}
                        DELETE /article/:id.:format             {:action=>"destroy", :controller=>"article"}
                               /:controller/:action/:id
                               /:controller/:action/:id.:format

所有的路由规则上面，都加上了admin这个namespace。

下面就要将views目录下面的articles目录改到views/admin目录下面，因为根据路由规则，会到views/admin/articles/目录下面去查找相应的模板。

另外，还需要将原来的new_article_url | new_article_path等helper方法修改为new_admin_article_url | new_admin_article_path，将这些helper方法全部加上admin这个namespace。

Martian 2009-04-10 16:56 发表评论

[转]Why I like Ruby #1: alias_method

Martian — Fri, 03 Apr 2009 08:18:00 GMT

So you found yourself in the need to override a method but still count on it’s old behaviour?

No problem! Override it with your new code, call super and…. Uh oh!! Suddenly this turned into a problem… Let me give some more context.

I was testing Ferret (and the acts_as_ferret plugin) in a project to provide full text search capabilities to our models. One of the things the plugin does is to add a new method to ActiveRecord, called find_with_ferret. That way, every model can use it. Great!

So I thought that would make sense for me to remove all diatrictics from the input text before letting ferret do its job. You know, like removing umlauts and all that.

I could do that by overriding this method with code to remove the undesired chars and then call its older version to finally do the search - something like calling super, but not quite. And I didn’t want my models to inherit from anything else than ActiveRecord::Base. That wouldn’t make any sense.

alias_method to the rescue!

You know that to redefine a method in an existing class you can open it up and rewrite it. But since you don’t wanna loose the behaviour provided by the original method, this is how you can achieve this:

module ActiveRecord
  class Base
    alias_method :find_with_ferret_original, :find_with_ferret

    def find_with_ferret(q, options = {}, find_options = {})
      remove_diatrictics!(q)
      find_with_ferret_original(q, options, find_options)
    end
  end
end

And you’re good to go. On line 3 you’re just giving the original method an alias, making a copy of it.

Then you redefine it the way you like and on line 6 you call the old version to make sure u still got the same behaviour.
Now all my models can benefit of this change without requiring them to call another method nor inherit from another class.

Cool, huh?

Martian 2009-04-03 16:18 发表评论

修改Easy_Fckeditor上传图片的目录

Martian — Fri, 03 Apr 2009 01:32:00 GMT

修改文件上传目录
easy_fckeditor默认的文件上传目录为
public/uploads/Image，全部上传的图片都会被上传的该目录下，为了方便管理，将上传的图片根据上传日期上传到不同的日期目录下：
需要修改几个方法：

def current_directory_path
    base_dir = "#{UPLOADED_ROOT}/#{params[:Type]}/#{ Time.now.strftime('%Y%m%d') }"
#    Dir.mkdir(base_dir, 0775) unless File.exists?(base_dir)
    FileUtils.mkdir_p base_dir
    check_path("#{base_dir}#{params[:CurrentFolder]}")
    "#{base_dir}"
end

def upload_directory_path
    #    uploaded = request.relative_url_root.to_s + "#{UPLOAD_FOLDER}/#{params[:Type]}"
    uploaded = ActionController::Base.relative_url_root.to_s+"#{UPLOADED}/#{params[:Type]}" + "/"  + Time.now.strftime('%Y%m%d')
    "#{uploaded}#{params[:CurrentFolder]}"
end

主要是加个日期Time.now.strftime('%Y%m%d'),将上传后的图片上传到public/uploads/Image/20090403/目录下，如果要换另一种形式，也很方便，将Time.now.strftime('%Y%m%d')改成自己需要的就可以了。

Martian 2009-04-03 09:32 发表评论

Rails Plugin: Easy Fckeditor

Martian — Thu, 02 Apr 2009 14:57:00 GMT

#安装easy fckeditor插件，需要首先安装git
ruby script/plugin install git://github.com/gramos/easy-fckeditor.git

#使用rake安装fckeditor
rake fckeditor:install

** Installing FCKEditor Plugin version 0.8.1
Creating directory editor
Creating directory css
Creating directory behaviors
  Installing file disablehandles.htc
  Installing file showtableborders.htc
  Installing file fck_editorarea.css
  Installing file fck_internal.css
  Installing file fck_showtableborders_gecko.css
Creating directory images
  Installing file block_address.png
  Installing file block_blockquote.png
  Installing file block_div.png
.
.
.
  Installing file fckplugin.js
  Installing file _upgrade.html
  Installing file _whatsnew.html
  Installing file _whatsnew_history.html
** Successfully installed FCKEditor Plugin version 0.8.1

#在需要使用Fckeditor的页面引入fckeditor.js文件

<%= javascript_include_tag :fckeditor %>

#使用fckeditor_textarea

<%= fckeditor_textarea :article, :body, {:toolbarSet => 'Easy', :width => '100%', :height => '300px'} %>

#更详细的使用说明，可以参看http://github.com/gramos/easy-fckeditor/tree/master

解决上传图片问题

1. 在上传图片的时候(rails2.2.2)，会出现如下的错误：

NoMethodError (undefined method `relative_url_root' for #):

解决方法参考 http://github.com/salicio/fckeditor/commit/fcf8fbee8cfad3a3df0df50172e448727909ccb9
1. 将/vendor/plugins/easy_fckeditor/app/controllers/fckeditor_controller.rb中的
uploaded = request.relative_url_root.to_s+"#{UPLOADED}/#{params[:Type]}"
修改为:
uploaded = ActionController::Base.relative_url_root.to_s+"#{UPLOADED}/#{params[:Type]}"
2. 将/vendor/plugins/easy_fckeditor/lib/fckeditor.rb中的
js_path = "#{controller.relative_url_root}/javascripts"
修改为：
js_path = "#{ActionController::Base.relative_url_root}/javascripts"

2. 该plugins版本少定义了一个变量：
会出现如下错误：

NameError (uninitialized constant FckeditorController::UPLOADED):

修改很简单，只要修改
/vendor/plugins/easy_fckeditor/app/controllers/fckeditor_controller.rb,增加:
UPLOADED = "/uploads"

完成之后，能够正常上传图片，并预览。

Martian 2009-04-02 22:57 发表评论

install ruby on rails, sqlite3, sqlite3-ruby under ubuntu8.10

Martian — Wed, 01 Apr 2009 06:57:00 GMT

nothing but the script I used:

#install Ruby and relative
apt-get install ruby

#install wget
sudo apt-get install wget

#install rubygems
wget http://rubyforge.org/frs/download.php/45905/rubygems-1.3.1.tgz
tar xzf rubygems-1.3.1.tgz
cd rubygems-1.3.1
sudo ruby setup.rb
gem -v
1.3.1

# or update rubygems
sudo gem install rubygems-update -v 1.3.1

#install Rails and dependencies
gem install rails –include-dependencies -v=2.2.2

#install Sqlite3

apt-get install sqlite3 swig libsqlite3-ruby libsqlite3-dev

apt-get install ruby1.8-dev libsqlite3-dev (required)

gem install sqlite3-ruby #compile this need libsqlite.h

Martian 2009-04-01 14:57 发表评论

ActiveRecord级联删除

Martian — Mon, 30 Mar 2009 13:00:00 GMT

Rails在关联关系中，han_one和has_many都有一个:dependent选项，告诉ActiveRecord在删除父记录时该如何处理子记录，它有五个属性(AWDWR)：

:dependent => :destroy(或true) --- 删除父记录的同时删除子表中的记录
:dependent => :nullify --- 删除父记录之后保留子记录，同时将子记录的外键值设置为null
:dependent => :false(或nil) --- 删除父记录时不改变子记录。

但是在使用的过程中，设置为:destroy或:nullify，都没有达到效果，由于使用的是rails2.2.2，看了一下has_many的源码：

      # [:dependent]
      #   If set to :destroy all the associated objects are destroyed
      #   alongside this object by calling their +destroy+ method.  If set to :delete_all all associated
      #   objects are deleted *without* calling their +destroy+ method.  If set to :nullify all associated
      #   objects' foreign keys are set to +NULL+ *without* calling their +save+ callbacks. *Warning:* This option is ignored when also using
      #   the :through option.

发现选项已经变成了：

:destroy
:delete_all
:nullify

但发现也没有达到要求。

最后发现controller代码中调用的是ActiveRecord的delete方法，换成destroy方法后，发现能够正常地级联删除子记录。
对于ActiveRecord，delete方法不能级联删除子记录，而要使用destroy方法。

Martian 2009-03-30 21:00 发表评论

MySQL5.1.x的驱动有问题？

Martian — Sun, 29 Mar 2009 10:36:00 GMT

今天把MySQL换成了5.1版本的，使用rake db:create的时候，出现了一个error，但是能够正常地在数据库中创建database，但使用rake db:migrate的时候，就报错说无法使用"show tables"这个命令，但表还是正常的生成了。可在使用过程中，只要涉及到写数据库的操作，都会异常退出server，把MySQL换成5.0版本的，问题就解决了，估计是驱动问题。

Martian 2009-03-29 18:36 发表评论