自从升级到Rails 3.1，我在我的开发日志中看到了这条警告消息:

警告无法确定响应体的内容长度。设置响应的content-length或设置response #chunked = true

这是什么意思，我如何删除它?有问题吗?

我正在寻找一种简单的方法来解析JSON，提取值并将其写入Rails中的数据库。

具体来说，我正在寻找的是一种方法，从从位返回的JSON中提取shortUrl。ly API:

{
  "errorCode": 0,
  "errorMessage": "",
  "results":
  {
    "http://www.foo.com":
    {
       "hash": "e5TEd",
       "shortKeywordUrl": "",
       "shortUrl": "http://bit.ly/1a0p8G",
       "userHash": "1a0p8G"
    }
  },
  "statusCode": "OK"
}

然后把那个短URL写进一个与长URL相关的ActiveRecord对象。

这是我可以完全从概念上思考的事情之一，当我坐下来执行时，我意识到我有很多东西要学习。

每次我运行rails 4.0服务器时，都会得到这样的输出。

Started GET "/" for 127.0.0.1 at 2013-11-06 23:56:36 -0500

PG::ConnectionBad - could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Connection refused
Is the server running on host "localhost" (fe80::1) and accepting
TCP/IP connections on port 5432?
:
 activerecord (4.0.0) lib/active_record/connection_adapters/postgresql_adapter.rb:825:in `connect'
 activerecord (4.0.0) lib/active_record/connection_adapters/postgresql_adapter.rb:542:in `initialize'
 activerecord (4.0.0) lib/active_record/connection_adapters/postgresql_adapter.rb:41:in `postgresql_connection'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:440:in `new_connection'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:450:in `checkout_new_connection'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:421:in `acquire_connection'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:356:in `block in checkout'
 /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:355:in `checkout'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
 /System/Library/Frameworks/Ruby.framework/Versions/2.0/usr/lib/ruby/2.0.0/monitor.rb:211:in `mon_synchronize'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
 activerecord (4.0.0) lib/active_record/connection_adapters/abstract/connection_pool.rb:546:in `retrieve_connection'
 activerecord (4.0.0) lib/active_record/connection_handling.rb:79:in `retrieve_connection'
 activerecord (4.0.0) lib/active_record/connection_handling.rb:53:in `connection'
 activerecord (4.0.0) lib/active_record/migration.rb:792:in `current_version'
 activerecord (4.0.0) lib/active_record/migration.rb:800:in `needs_migration?'
 activerecord (4.0.0) lib/active_record/migration.rb:379:in `check_pending!'
 activerecord (4.0.0) lib/active_record/migration.rb:366:in `call'
 actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:29:in `block in call'
 activesupport (4.0.0) lib/active_support/callbacks.rb:373:in `_run__1613334440513032208__call__callbacks'
 activesupport (4.0.0) lib/active_support/callbacks.rb:80:in `run_callbacks'
 actionpack (4.0.0) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
 actionpack (4.0.0) lib/action_dispatch/middleware/reloader.rb:64:in `call'
 actionpack (4.0.0) lib/action_dispatch/middleware/remote_ip.rb:76:in `call'
 better_errors (0.9.0) lib/better_errors/middleware.rb:84:in `protected_app_call'
 better_errors (0.9.0) lib/better_errors/middleware.rb:79:in `better_errors_call'
 better_errors (0.9.0) lib/better_errors/middleware.rb:56:in `call'
 actionpack (4.0.0) lib/action_dispatch/middleware/debug_exceptions.rb:17:in `call'
 actionpack (4.0.0) lib/action_dispatch/middleware/show_exceptions.rb:30:in `call'
 railties (4.0.0) lib/rails/rack/logger.rb:38:in `call_app'
 railties (4.0.0) lib/rails/rack/logger.rb:21:in `block in call'
 activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `block in tagged'
 activesupport (4.0.0) lib/active_support/tagged_logging.rb:25:in `tagged'
 activesupport (4.0.0) lib/active_support/tagged_logging.rb:67:in `tagged'
 railties (4.0.0) lib/rails/rack/logger.rb:21:in `call'
 quiet_assets (1.0.2) lib/quiet_assets.rb:18:in `call_with_quiet_assets'
 actionpack (4.0.0) lib/action_dispatch/middleware/request_id.rb:21:in `call'
 rack (1.5.2) lib/rack/methodoverride.rb:21:in `call'
 rack (1.5.2) lib/rack/runtime.rb:17:in `call'
 activesupport (4.0.0) lib/active_support/cache/strategy/local_cache.rb:83:in `call'
 rack (1.5.2) lib/rack/lock.rb:17:in `call'
 actionpack (4.0.0) lib/action_dispatch/middleware/static.rb:64:in `call'
 railties (4.0.0) lib/rails/engine.rb:511:in `call'
 railties (4.0.0) lib/rails/application.rb:97:in `call'
 rack (1.5.2) lib/rack/content_length.rb:14:in `call'
 thin (1.5.1) lib/thin/connection.rb:81:in `block in pre_process'
 thin (1.5.1) lib/thin/connection.rb:79:in `pre_process'
 thin (1.5.1) lib/thin/connection.rb:54:in `process'
 thin (1.5.1) lib/thin/connection.rb:39:in `receive_data'
 eventmachine (1.0.3) lib/eventmachine.rb:187:in `run'
 thin (1.5.1) lib/thin/backends/base.rb:63:in `start'
 thin (1.5.1) lib/thin/server.rb:159:in `start'
 rack (1.5.2) lib/rack/handler/thin.rb:16:in `run'
 rack (1.5.2) lib/rack/server.rb:264:in `start'
 railties (4.0.0) lib/rails/commands/server.rb:84:in `start'
 railties (4.0.0) lib/rails/commands.rb:78:in `block in <top (required)>'
 railties (4.0.0) lib/rails/commands.rb:73:in `<top (required)>'
 bin/rails:4:in `<main>'

我运行的是Mavericks OS X 10.9，所以我不知道这是否是问题所在。我已经尽力了，但似乎都没用。我已经卸载和安装postgres和pg gem多次了。

这是我的数据库。yml文件

development:
  adapter: postgresql
  encoding: unicode
  database: metals-directory_development
  pool: 5
  username: 
  password: 
  template: template0
  host: localhost
  port: 5432

test: &test
  adapter: postgresql
  encoding: unicode
  database: metals-directory_test
  pool: 5
  username: 
  password: 
  template: template0
  host: localhost
  port: 5432

staging:
  adapter: postgresql
  encoding: unicode
  database: metals-directory_production
  pool: 5
  username:
  password:
  template: template0
  host: localhost

production:
  adapter: postgresql
  encoding: unicode
  database: metals-directory_production
  pool: 5
  username:
  password:
  template: template0
  host: localhost

cucumber:
  <<: *test

如何获取Rails应用程序的根目录路径?

Rails用命名路由定义了一堆神奇的东西，它们为你的路由提供了帮助。有时候，特别是对于嵌套路由，跟踪给定路由助手方法调用的URL可能会让人有点困惑。是否可以使用Ruby控制台查看给定的helper函数将生成什么链接?例如，给定一个像post_path(post)这样的命名助手，我想看看生成了什么URL。

我正在开发一个非常基本的购物车系统。

我有一个表items，它的列价格类型为整型。

我在视图中显示包含欧元和美分的价格时遇到了麻烦。在Rails框架中处理货币时，我是否遗漏了一些明显的东西?

我们最近遇到了一个问题，在一系列提交之后，一个后端进程无法运行。现在，我们都很乖，每次签入后都会运行rake测试，但是，由于Rails库加载中的一些奇怪之处，它只在我们直接从Mongrel在生产模式下运行时才会发生。

我追踪了这个bug，它是由于一个新的Rails gem覆盖了String类中的一个方法，这种方法破坏了运行时Rails代码中的一个狭窄使用。

总之，长话短说，有没有一种方法，在运行时，问Ruby在哪里定义了一个方法?类似于whereami(:foo)，返回/path/to/some/file。Rb线45号?在这种情况下，告诉我它是在类String中定义的是没有帮助的，因为它被一些库重载了。

我不能保证源生活在我的项目，所以grepping 'def foo'不一定给我我需要的，更不用说，如果我有很多def foo's，有时我不知道，直到运行时，我可能会使用哪一个。

我有一些字体被配置在我的Scss文件如下:

@font-face {
  font-family: 'Icomoon';
  src: asset-url('icoMoon.eot?#iefix', font) format('embedded-opentype'),
       asset-url('icoMoon.woff', font) format('woff'),
       asset-url('icoMoon.ttf', font)  format('truetype'),
       asset-url('icoMoon.svg#Icomoon', font) format('svg');
}

实际的字体文件存储在/app/assets/fonts/中

我添加了config.assets.paths << Rails.root。加入(“应用程序”，“资产”，“字体”)到我的应用程序。rb文件

编译CSS源代码如下:

@font-face {
  font-family: 'Icomoon';
  src: url(/assets/icoMoon.eot?#iefix) format("embedded-opentype"), url(/assets/icoMoon.woff) format("woff"), url(/assets/icoMoon.ttf) format("truetype"), url(/assets/icoMoon.svg#Icomoon) format("svg");
}

但当我运行应用程序的字体文件没有被发现。日志:

start GET "/assets/icoMoon.ttf" for 127.0.0.1 at 2012-06-05 23:21:17 +0100 已服务资产/icoMoon.ttf - 404 Not Found (13ms)

为什么资产管道不把字体文件压缩成/assets?

大家有什么想法吗?

亲切的问候, 尼尔。

额外信息:

当检查rails控制台的资产路径和assetprecompile时，我得到如下:

1.9.2p320 :001 > y Rails.application.config.assets.precompile
---
- !ruby/object:Proc {}
- !ruby/regexp /(?:\/|\\|\A)application\.(css|js)$/
- .svg
- .eot
- .woff
- .ttf
=> nil



1.9.2p320 :002 > y Rails.application.config.assets.paths
---
- /Users/neiltonge/code/neiltonge/app/assets/fonts
- /Users/neiltonge/code/neiltonge/app/assets/images
- /Users/neiltonge/code/neiltonge/app/assets/javascripts
- /Users/neiltonge/code/neiltonge/app/assets/stylesheets
- /Users/neiltonge/code/neiltonge/vendor/assets/images
- /Users/neiltonge/code/neiltonge/vendor/assets/javascripts
- /Users/neiltonge/code/neiltonge/vendor/assets/stylesheets
- /Users/neiltonge/.rvm/gems/ruby-1.9.2-p320@neiltonge/gems/jquery-rails-2.0.0/vendor/assets/javascripts
- /Users/neiltonge/.rvm/gems/ruby-1.9.2-p320@neiltonge/gems/coffee-rails-3.2.1/lib/assets/javascripts
- /Users/neiltonge/.rvm/gems/ruby-1.9.2-p320@neiltonge/gems/bourbon-1.3.0/app/assets/stylesheets
- !ruby/object:Pathname
  path: /Users/neiltonge/code/neiltonge/app/assets/fonts
 => nil

假设我有下面的字符串

@x = "<a href='#'>Turn me into a link</a>"

在我的视图中，我希望显示一个链接。也就是说，我不希望@x中的所有内容都未转义并显示为字符串。使用有什么区别

<%= raw @x %>
<%= h @x %>
<%= @x.html_safe %>

?

在rails >4.0.0生成器使用before_action而不是before_filter创建CRUD操作。它似乎做着同样的事情。这两者有什么区别呢?