Api错误定制Rails 3,如Github api v3

Question

我在Rails3应用程序上添加了一个API,它非常好用.但我在http://developer.github.com/v3/看到了以下Github api v3

HTTP/1.1 422 Unprocessable Entity
 Content-Length: 149

 {
   "message": "Validation Failed",
   "errors": [
     {
       "resource": "Issue",
       "field": "title",
       "code": "missing_field"
     }
   ]
 }

我喜欢错误消息结构.但无法让它重现.我怎样才能让我的apis做出类似的回应？

Answer 1

通过为 JSON 格式添加 ActionController::Responder，您可以轻松实现该错误格式。有关此类的（极其模糊）文档，请参阅http://api.rubyonrails.org/classes/ActionController/Responder.html，但简而言之，您需要重写 to_json 方法。

在下面的示例中，我在 ActionController:Responder 中调用私有方法，该方法将构造 json 响应，包括您选择的自定义错误响应；你所要做的就是填补空白，真的：

def to_json
  json, status = response_data
  render :json => json, :status => status
end

def response_data
  status = options[:status] || 200
  message = options[:notice] || ''
  data = options[:data] || []

  if data.blank? && !resource.blank?
    if has_errors?
      # Do whatever you need to your response to make this happen.
      # You'll generally just want to munge resource.errors here into the format you want.
    else
      # Do something here for other types of responses.
    end
  end

  hash_for_json = { :data => data, :message => message }

  [hash_for_json, status]
end